study unit basic metalworking and machine tool operation

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Study Unit

Basic Metalworking andMachine Tool OperationBy

William Schumaker

Education Direct

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About the Author

William “Bill” Schumaker was born of Swiss immigrant parents on October 19, 1915, on a

backwoods homestead near Colville, Washington. Elk, deer, bear, pheasants, grouse, rabbits,

and other small game were plentiful in Bill’s youth. No wonder he took an intense early inter-

est in hunting and guns. Bill hand filed his first “gunsmithing” work while in the fifth grade—

a front sight made from a fire-annealed piece of half-round file and a copper penny. Somehow,

this tiny creation still sits in a box somewhere in Bill’s shop despite endless moves, and a

world war!

While in high school, Bill joined the Fort Colville Gun Club. He became small-bore rifle champi-

on within two years. Bill thrived on competition and so he won many events prior to becoming

Washington State Gallery Champion in 1941. In 1942, he set a new national record.

World War II sent Bill through Aircraft mechanics school, but his firearms skills prevailed.

Soon he was armament chief on a squadron of B-17s and B-24s, as well as becoming top

Non-Com of Air Force ground training in small arms at Bradley Field, Connecticut.

After World War II, Bill resumed his civilian rifle competition with a vengeance. He recaptured

the Washington State Championship in 1949, and he won the Idaho State Championship in

1956. Between triumphs he was Inland Empire Aggregate Winner from 1947 through 1949,

high man on Spokane’s winning 1949 Hearst team, and NRA Sectional Champion in 1953

and 1956.

Bill loved the English language from his youth, although he spoke fluent German before learning

English. Bill loved writing also and he sold his first gun-hunting story to GUNS magazine in

1948. He soon began writing the “Gunsmithing Bench” column for Shooting Industry Magazine,

a post he kept for about 25 years. Bill also wrote the “Workshop” column for New York’s Guns

& Game Magazine for about six years. He has authored for Guns & Ammo, Shooting Times,

Gun World, Outdoor Life, and Petersens Hunting. His color photographs have appeared on the

covers of American Rifleman, GUNS, and Guns & Game Magazines, Spokesman-Review Hunting

Edition.

Bill still does gunsmithing work at his near-the-home shop. He still takes photo and writing

assignments, and yes, he still shoots rifle with his local club.

iii

In this study unit, you’ll learn how various

metalworking tools serve the gunsmith.

Some tools are simply prerequisite to gainful

employment in the field and you should

purchase them immediately. A quality drill

press for drill and tap scope work is just one

example. An assortment of hand tools, a grinder, and a good

solid vise are others. Fortunately, most of these basic tools

are relatively inexpensive. Unfortunately, some tools, like a

lathe, milling machine, and welding equipment, are quite

expensive. These too, however, soon become a necessity for

those pursuing specialty gunsmithing.

We approach this unit from a task-oriented perspective. We

stress that those purchasing more advanced metalworking

tools should be sensible enough to obtain proper training in

their use. We cover practical application and safety rather

than basic startup procedures. Those coming to this unit

with an eye to identifying metalworking tools and how they

can generate profit will find themselves well served. Those

who already possess a metalworking background, along

with those who don’t, will learn much from this gunsmithing

legend.

When you complete this study unit, you’ll be able to • Recognize various metalworking tools and identify their uses

• Demonstrate how to fit a gun barrel to an action

• Explain how to open a bolt face in a lathe

• Discuss how to alter military and other bolt handles forscope mounting

• Perform precision sear facing with mini-tool post grinders

• Summarize drill and tap and scope mounting procedures

• Diagnose and correct cartridge feeding problems

• Jewel a bolt

• Build your own glass bead blasting cabinet

• Build your own belt sander

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PROFESSIONAL HAND AND POWER GUNSMITHING TOOLS 1

Introduction 1Fitting New Military Barrels 2Bench Grinders 3Hand Tools around the Benches 4Drilling and Tapping 5

STRAIN-FREE SCOPE MOUNTING 15

Shooting a Scope under Strain 18Scope Alignment Rods Are Helpful 18Scope Centers Vary 19Bolt Jeweling with a Drill Press 23

MILITARY RIFLE BOLT FORGING 20

Longer Bolt Handle Breakthrough 23The Bench Grinder 31Grinder-trimming Forged Bolts 33The Importance of Bench Grinders 34Shop-required Buffing Equipment 35

DIAGNOSING AND CORRECTING CARTRIDGE FEEDING PROBLEMS 39

Whipping Knife-sharp Extractor without Tension 42Emergency Alteration 44Action-rail Tolerances 44Correcting Cartridge Jump-outs 47Influential Magazine Follower Dimensions 47Wrong Feeding Diagnosis on Military Krag Rifle 48

THE LATHE: KING OF GUNSMITHING TOOLS 50

A Barrel Vise 51Gunsmith-built Action Wrench Hammer 52The Complete Shop 53Details of a Barrel Fitting 53Stainless Steel vs Chrome-moly Barrels 59Shop Tips 60

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Contentsvi

BOLT FACE OPENING (MANGUMIZING) IN THE LATHE 62

Precision Sear Facing with Mini-tool Post Grinders 66Drill Rod for Making Parts 68W-1 Water-hardening Drill Rod 69

SHAPING MUZZLES 72

Growing Barrel Muzzels (Sporters/Target) 72How to Crown (Face-off) Shotgun Muzzles 73

ADVANCED GUNSMITHING SKILLS 77

The Palmgren Milling Attachment for the Lathe 77Lathe-making a Tap 79The Milling Machine 81Welding Requirements 83Soft-soldering vs Silver Soldering 86Front Sight Installation 86Parts-holding at the Workbenches 88Joining Two Firing Pins 91

BUILDING YOUR OWN EQUIPMENT 94

Building a Glass Bead Blasting Cabinet 94Plans for a Belt Sander 95

SELF-CHECK ANSWERS 107

EXAMINATION 117

1

PROFESSIONAL HAND ANDPOWER GUNSMITHING TOOLS

Introduction

The old adage that a craftsman is only as good as his or her

tools is especially true of gunsmithing. I remember when I

started out. For several years an ever-prevailing financial

bottleneck prevented me from purchasing adequate equip-

ment and tools. My earning potential suffered as well as my

professional development. For example, although my shop

had a homemade buffer, a medium-value drill press, welding

outfit, and a good eight inch bench grinder, I had to send

rebarreling work to an “equipped” gunsmith, which was both

costly and time-consuming. I felt I conveyed the impression

that I was merely a dealer—not a gunsmith. Initial public

impressions about a new business are difficult to change.

I begin this study unit by conveying an important message to

you, a message you’ll undoubtedly hear from other Gunsmith

authors—if you haven’t heard it already. The message is that

good tools pay for themselves. You can accomplish a lot of

work and make a lot of money using quality hand tools. Then,

if and when needs arise and finances allow, you can add a

quality drill press and a bench grinder to your shop. Also,

those who specialize in metalwork might find that a lathe

and/or milling machine and welding equipment are in order.

There’s no denying that such equipment is expensive. Before

making an investment, carefully evaluate whether the invest-

ment is warranted. On an almost daily basis, gunsmithing

supply houses introduce tools that make task completion

Basic Metalworking and Machine Tool Operation

easier and less expensive. For example, you can order a

semifinished prethreaded barrel and do the final fitting with

relatively inexpensive (compared to a lathe) hand tools. Also,

you may decide to send the action out to a shop that special-

izes in barrel work. Most barrel shops offer dealer discounts,

so you can still make some money for handling such work.

I believe that if you use a tool frequently, it will pay for itself.

I do a lot of metalwork in my shop, and I consider a lathe

and welding equipment to be necessities. Although I have

(and frequently use) a milling machine, we can accomplish

some gunsmithing tasks covered later in this unit with a

Palmgren milling attachment on the lathe. I present this

option in light of avoiding the steep cost of a milling machine.

When I began gunsmithing, I didn’t purchase any expensive

machinery right away. I don’t recommend that you do either.

In fact, you shouldn’t even consider expensive machinery

until you’re properly schooled in its operation and qualified

to evaluate its worth. This way, if and when you do make an

expensive new or used purchase, you’ll be sure to get your

money’s worth.

Warning: Lathes, milling machines, welding equipment, and

hand tools are dangerous in inexperienced hands. In the case

of hand tools, always follow instructions provided for their

proper and safe use and heed manufacturer warnings!

Concerning operating advanced equipment and machinery,

many technical trade schools and community colleges offer

“hands-on” instruction in the proper use of advanced equip-

ment and machinery. Seek these schools out and obtain

proper training before trying to use advanced equipment and

machinery. When I was starting out, because of necessity, I

learned a lot through trial and error. Fortunately, times have

changed. Take advantage of available training.

Fitting New Military Barrels

Early in my gunsmithing career, many customers came to

my shop with surplus 1903 Springfields and 1917 Enfields

that had badly worn and damaged barrels. New ones were

available by the dozen at a modest cost then. Fortunately,

most new military barrels were chambered slightly short. A

Basic Metalworking and Machine Tool Operation2

Basic Metalworking and Machine Tool Operation 3

new .30–06 removable piloted finishing reamer in conjunction

with a heavy Vickerman barrel vise enabled me to handle

this situation, although hand-reaming—which I no longer

advise—was necessary then.

Sometimes, the new barrel chamber was already too deep

(with excessive headspace), or those nuisance Springfield and

Enfield extractor slots and cone-shaped chamber approaches

required altering. Consequently, I had to wrap up a package,

write a letter, and send a check to another gunsmith. I felt

that I was losing profits, time, and reputation. Eventually,

I purchased a lathe.

You’ll never realize how many types of jobs you can do with a

lathe until you learn to operate one. If your shop is in a rural

or small-town area and time allows, you’ll also be making

parts for equipment besides guns. A shop with equipment

attracts and impresses customers and visitors. My point,

again, is that increased business will pay for better and more

equipment.

Bench Grinders

Those who claim you won’t ever need a bench grinder don’t

remember the early military conversion heydays when grind-

ing off big 1917 Enfield ears was an almost daily task. The

work required a heavy-duty, 8 inch wheel grinder to do a

good job, and the grinder has many other uses.

Further into this unit when discussing low bolt forging, I

mention a medium-class grinder fitted with cut-off wheels,

plus a smaller 1/4 hp (horsepower) grinder near the main

workbench. My point is that as business picks up, you can’t

beneficially change grinding wheels on your “one” grinder.

Grinder wheels must be diamond trimmed into balance and

left in that position on their respective machines. I have

instant access to six different wheels. As soon as you can

afford it, you should too. You’ll realize the need even more

if your shop graduates to having a helper.

Hand Tools around the Benches

Files, hammers, wrenches, punches of many types, stocking

chisels, scrapers, knives and endless other items line the

fringes of gun shop workbenches. It’s important that you

keep your tools easily visible and accessible. Wooden clothes-

pins work great for small tools and won’t scar or magnetize

them. Take one half of the clothespin off its spring clamp,

drill small holes in the tapered thin end, and tack it to a ply-

wood back plate on the wall behind the benches. Arrange

their height and spacing according to tools and your taste

(Figure 1).

As you progress, you’ll need a 1 inch and a 2 inch microme-

ter, a depth micrometer, calipers, and endless other tools.

Listing everything I can think of is useless because you


FIGURE 1—Shown is mysimple, low-cost, minimum-effort wall toolholder. Itreated the back sides ofthe wooden clothes pinswith 3 minute epoxy to holdthe pins in place. With thisarrangement, dozens oftools are within sight andinstant reach.


already have the Brownell’s gunsmithing supply catalog.

Common sense and logic dictate a good starting lineup.

You should acquire more tools as the need arises.

Drilling and Tapping

Most gunsmiths have probably spent more time drilling and

tapping and installing scope mounts and sight bases than

they’ve devoted to all other in-shop activities. This was espe-

cially true directly after World War II when countless military

rifles were transferred to civilian ownership. While the big

rush is over, new supplies of old military rifles keep coming;

hence, the importance of becoming adept at drilling and

tapping (Figure 2).

Many barrels are hard and extremely difficult to work with

despite the latest super-hard drills and better taps. Although

we can drill almost anything, cutting a thread in the drilled

holes is still a leading troublemaker.

Before hole location action jigs were available, it was com-

mon to use a parallel-jawed caliper to square the scope base

on the action top relative to the underside of the action flat.

Then a gunsmith would use a thin, hard scribe to reach

through the screw attaching holes to scribe the hole position.

FIGURE 1—Shown is my FIG-URE 2—You can sharpen dulltaps with a small emery stonein a Dremel tool post grinder.

Next the gunsmith would center-punch and drill the holes

one at a time. Often it was merely a “try-to-drill-the-hole”

effort unless you used some hard drills available through

gunsmiths’ supply houses. Unfortunately, super-hard (car-

bide) drills break easily—especially as they go through the

action.

The easiest and best thing to do is to purchase #31 “hard”

drills, along with the best taps available. A three-flute carbon

tap has narrow cutting lands. It won’t endure as much cut-

ting torque as a two-flute high-speed steel tap. However, if

you ever break a two-flute high-speed tap in a hole, you’ve

had it! Or more aptly, it has you! Unless you have room to

reposition the hole, the only out is sending the barreled

action to a shop equipped with an ultramodern electric

discharge machine (EDM), which can actually burn it out,

yet save the thread. This is why many gunsmiths went to

carbon, three-flute taps. If broken, you can shatter and

chip them out of the hole—sometimes!

Depending on how tight the tap is at breakage, the three-

prong tap removal tools sometimes work. Due to the extra

thread-lands surface of the two-flute taps, the removal tool

can seldom move them, which emphasizes the need to han-

dle small 6–48 taps delicately. Use tapping compounds/oils

liberally, such as Do-Drill and others. Start the thread with a

new taper tap. If it’s a bottomed hole, grind off the dead point

tip of the tap to lengthen the reach. The original grind of

some taper taps prohibits use in a bottomed hole.

Alternate Taps

Every tap is slightly different. After you easily turn one tap

into a hole as far as your skilled hands safely determine,

carefully remove it. Take another tap to try threading deeper,

or slightly enlarge the thread. I never throw away a tap until

it’s down to a mere stub. Keep grinding away the worn front

end and relieve the lands’ heel clearance a bit on a grit-coat-

ed buffing wheel. I’ve worked many a satisfactory thread into

a hard, tight hole by using the alternate-taps system. You

must develop a genuine, tender-yet-firm feel for safe tapping.

Experience teaches you how much pressure you can apply

on your tap wrench for a given tap, hole, and situation.



Anneal Hole Area

Annealing (softening metal) the spot to be drilled makes

tapping much easier. When working with different actions,

steels, and heat treatments, annealing is difficult. Inexpe-

rienced gunsmiths have probably “hardened” more actions

than they’ve annealed, which creates danger.

Warning: Never apply heat to an entire unshielded receiver

ring area! Preferably, remove military barrels from actions

before annealing, drilling, and tapping.

Removing barrels from actions takes longer only theoretically!

With the barrel out, you can drill all the way through the

front of the action. It’s much easier to tap. You can deburr the

hole(s) on the inside breakthrough area, saving tap chipping.

In the event you drill a hole with a super-tough professional

drill, you can anneal it after drilling (and much more evenly).

Furthermore, in the event a carbon tap gets broken in a

through-hold, it’s easier to punch it through, shatter, or pick

it out. You should apply heat with a medium-small acetylene

torch tip to the hole or receiver spot, protected with wet

asbestos around outside extremities. Prior to applying torch

heat, you should polish the metal surface white. Watch the

metal color slowly draw to blue, hold briefly with retracted

flame tip, retract more, and allow the steel to cool slowly.

Warning: Removing all heat immediately, and letting the

steel cool rapidly via the mass of adjoining metal usually

hardens it, causing both danger and more troubles.

Grinding Drilling Location Spots

Whether you use a parallel clamp, calipers, or an elaborate

drilling jig, rescribing, concave spot grinding, and rescribing

several times as you progressively grind is probably most

important to accurate hole location and drilling. If the action

steel will take center-punch, this (added to the concave spot-

ting) does no harm. However, it’s usually not helpful, as

drills follow concave grinding spots nicely.

Using a Scope-mounting Jig

For scope mounting, the B-Square Professional Scope-

mounting Jig is available with complete directions (Figure 3).

Its flat base block, bore align arbor, V-bushings, drill bush-

ing, and jig bars for different actions assure you of perfect

top-of-the-actions holes positioning (Figure 4). It’s still to

your advantage to scribe the hole locations through the drill

bushing, remove the jig, and then concave grind the tiny drill

spot locations (Figures 5 and 6).


FIGURE 3—Drilling MauserM-98 with B-Square Scope-mounting Jig and Drill Bushing


FIGURE 4—A hardened drillbushing guides the drill andensures correct hole location.

FIGURE 5—After light center-punching through the drill jig,use an electric grinder with ainch emery stone to concavethe drill-starting spots. Afterrepositioning in the jig, re-center-punch through the jig’sdrill guide. Make a centerpunch from a broken carbidedrill for perfect alignmentthrough the drill guide. Thepunch can be accuratelypointed using your small toolpost grinder in a lathe.Center-punching through thedrill bushing provides perfectcentering.

Note: Starting a drill perfectly is important. You can make a

small effective center punch from a broken super-hard #31

drill.

More on Annealing

Another popular method for annealing is to use a steel block

or rod approximately 1 inch in diameter � 2 inches long.

Contour the end of the steel to contact hole areas of the

receiver. Heat the steel piece red-hot. Place it against the

receiver contacting the holes area and allow it to cool com-

pletely. This offers slightly better heat control. Cooling slowly

should condition the steel to drill and tap.

Note: Concerning drilling and tapping, one line of thought is

that if the metal is too hard to drill, it’s certainly too hard to

tap. If you can drill without hardened drills using only con-

ventional screw machine short drills, which also wander less,

then you can be reasonably sure you can also tap the metal.

There’s much truth to the saying that carbide drills just pre-

pare a hole in which you break your tap.


FIGURE 6—Sides of 1 1/4inch V-blocks provide an idealbase surface for the bottomflat of the Mauser and otherrifle actions. Slight shimmingin the drill press compoundvise allows tightening foraccurate drilling (Brownell’shard-coated #31 drill).


Standardizing Hole Spacing

There’s been an increased availability of military Mauser

rifles, and some Springfields and Enfields have been finding

their way back home. Consequently, most new gunsmiths

will discover that drilling and tapping such rifles is still a test

of gunsmithing skill. One still-unsolved problem is the various

scope base hole spacing used by different manufacturers.

Makers of quality adjustable scope mounts such as Redfield

and Beuhler give their bases a recoil lip that butts against

the rear of the receiver ring. Weaver and the lower-cost

imports lack a recoil lip and are installed at various fore and

aft positions. Inaccurate hole drilling and the fact that scopes

don’t all have perfect optical centers quite often make it

impossible to zero in a scope after it’s mounted.

You could adjust elevation with shimming, but left-right

(windage) remains fixed by the mounting screw holes’ loca-

tions (if there’s insufficient windage adjustment in the scope).

Therefore, military actions drilled for the nonstandard plain

aluminum bases by various gunsmiths wouldn’t accept a

substitute adjustable base. Factory rifles, on the other hand,

had drillings matched by the mount manufacturers. If non-

adjustable bases prevented a scope from being zeroed,

switching to an adjustable mount was easy! At the height of

scope mounting work in my shop, we ran into this situation

up to seven times annually.

When a customer insisted on the low-budget nonadjustable

scope, the gunsmith solved the problem by using an

adjustable base as a template. Then, if the need arose, it was

still possible to install the adjustable base.

Another trick often used on super-hard Enfield actions made

by Eddystone was to enlarge the hole made by the #31 drill

by running a #30 drill into it. This often made tapping possi-

ble without danger of stripping in that super-hard action.

Hand Tapping

Handheld tap wrenches and the chucked tap, even though

it’s a taper-tap, don’t always start in perfect alignment with

the hole. This can make an imperfect hole beginning, and in

shallow holes it could strip.

B-Square’s Tru-Tapper is a small secondary chuck with a

free vertical movement mandrel and T-handles for hand

working (Figure 7).

After drilling the hole, you must lower the drill press table

enough to remove the drill from the press and chuck up the

Tru-Tapper shank. Then, you realign the table. Use a new

and sharp, well-lubed taper-tap, and turn the Tru-Tapper

carefully with its T-handles, using slight downward feed-in

pressure to start the thread cut. After the tap is nicely start-

ed (straight), I prefer to take the action to the bench vise and

use my small, hand-operated tap wrench to finish the thread

(Figure 8).


FIGURE 7—The Tru-Tappergives positive in-line hole tapping. The jig keeps theaction level and in line.


FIGURE 8—Hand-Tapping theFront Scope Base Hole


Self-Check 1

At the end of each section of Basic Metalwork and Machine Tool Operation, you’ll be asked to pause and check your understanding of what you have just read by completing a “Self-Check” exercise. Answering these questions will help you review what you’ve studied so far. Please complete Self-Check 1 now.

Indicate whether the following statements are True or False.

_____ 1. Super-hard carbon drills are tough to break.

_____ 2. You should never apply heat to an unshielded receiver ring area.

_____ 3. You should never start a thread with a new taper tap.

_____ 4. A three-flute carbon tap has narrow cutting lands and won’t endure as much cuttingtorque as a three-flute high-speed steel tap.

_____ 5. Annealing the spot to be drilled will make tapping much easier.

Check your answers with those on page 107.


STRAIN-FREE SCOPE MOUNTING

Besides drilling and tapping for scope sight mounting, fixing

installations done by the customer on predrilled and tapped

factory rifles undoubtedly surpasses in frequency all other

facets of gunsmithing and gun work. Customers will bring

in a multitude of errors, mistakes, and “done-it-wrong” work

for you to correct. That’s where gunsmithing instructions,

training, and experience pay off.

Note: Prospective gunsmiths must learn to read, understand,

and practice all manufacturer’s instructions. Additionally,

gunsmiths must keep abreast of the latest developments and

never close their minds to further learning!

Before we get into the evils of scope strain within the mount

system, we need to first address the need for perfect rings-to-

scope fitting. You must follow the instructions with Buehler

scope mount rings. The majority of home install-it-yourself

hobbyists somehow fail to either read or follow them. If you

can read, study, and follow instructions, you’ll get substantial

work.

The first problem is that the so-called 1 inch diameter scope

bodies are seldom a true inch. You’ll discover this if you use

your micrometer on them from beginning to end. The high-

quality adjustable Buehler rings are machined and polished

in place for perfect fit. Their laminated shim pack peels off in

sections as required to bring the “into-the-front-base” ring

spud opening to a mating match with the bottom ring spud.

The diameter split and cross-screw are tensioned “tight” to

finalize a perfect fit.

Now we can proceed in obtaining a strain-free position for

your telescope sight. The Buehler mount (as does the

Redfield) employs a left and right opposing windage screw

system. The first big mistake many hobbyists make is leaving

the left windage screw in position at the mount rear as they

bring the ringed scope swing up to it. They presume in-bar-

rel-line, but careful observation reveals that swinging the

scope up to the left windage screw won’t positively position it

there. The scope is under some tension and recoils lightly to

the right. Far too many scope installers simply bring that

right windage screw into position and then force the rear

scope ring up against the left windage screw (under tension),

without worrying about it.

However, that’s the wrong way to do it! The left windage

screw should have been removed, as well as the right. When

swinging the ringed scope into barrel line under slight ten-

sion, move it slightly past center left and right, and with

increasingly shorter left-right movements, work out any left-

right tension (strain). Next, note if the bottom of the rear

scope ring easily bears onto the top of the rear scope base

between the windage screws. If it does, you’ve got it made.

Your scope is strain-free from front to rear rings. Turn in the

left and right windage screws to the relaxed centered rear

ring base, firm them up, bore-sight, and zero in on the range.

Note: Never rely on bore-sighting fixtures for a final zero.

If you have to push the rear scope ring and scope downward

(or upward) to contact the top of the scope mounting base

between the windage screws, you have damaging-to-zero

scope strain.

Scope strain isn’t always easy to work out. Often you can

have a strain-free scope pointing so far out of line with the

bore center that sighting in is impossible with the existing

internal scope adjustments. This calls for steel shims, often

ground to a taper, to laboriously bring the scope mounting

bases and rings into strain-free alignment.

Strain-free alignment might matter little to the average deer

hunter or plinker, but it’s a super item for target, silhouette,

and bench rest shooters, and most long-range varmint shoot-

ers are precisionists plus! “Scope strain” has become univer-

sally recognized by bench rest (BR) gunsmiths. So much so

that they work a 1 inch steel bar treated with lapping grit

back, forth, and around with a wrench to progressively tight-

en the rings as they lap until total inside contact is achieved.

Split steel rings respond best.

Note: It’s wise to get elevation alignment as close as possible

before doing the final lapping to bring the scope into a

relaxed position (from which it’s least likely to change).



Shooting a Scope under Strain

Scope body metals forcibly held in a bind (strain) can do

strange things. Some gradually shift hither and yon, but

most yearn to relax their way out of the position they were

forced into. Like an archery bow left strung for long periods

of time, a scope under strain eventually responds to most of

the force that overwhelms it, in this case strong scope rings

and mount bases. However, the process takes time. Response

may not be complete for years, and the shooter will suffer

accordingly throughout this period. Knowledge and good

gunsmithing can prevent such problems.

Scope Alignment Rods Are Helpful

Professionally made scope alignment rods consist of two alu-

minum rods that are pointed 60 degrees, 41/4 inches long,

and either 1 inch or 30 millimeters in diameter. After

installing a scope base on a rifle action, you should mount

the rods in the scope rings, points facing each other. If every-

thing is in line and you can bring the points to touch, the

scope taking their place in the rings is probably not under

any strain. If the alignment rod points can’t be perfectly

touch matched, some careful work remains.

The most common cause of mismatching rods is variation in

rifle actions, especially military types. Inaccurate drilling-tap-

ping work also causes problems. Front and rear scope bases

and/or one-piece scope bases must not only be level but

basically level with the axis of the rifle bore to a degree easily

adjusted with the scope’s internal adjustments.

Quality mounts have provisions for windage (left and right)

adjustment, which makes it easy to line up the alignment

rod points windage-wise. The big culprit can be elevation. In

Figure 9, the right rod point (at the arrow) is visibly higher

than the rod point mounted in the rear scope ring.

A scope installed in rings as pictured in Figure 9 would place

an undesirable bend and strain onto the scope body. The

strain affects accuracy, zero holding, and possibly the internal

optical system.

The easiest way out is to shape a steel shim the approximate

thickness of the elevation shortfall. The only other answer is

to contour-mill the underside of the front scope base.

The top overall surface length of the two rods should also be

level, as it’s possible for the points to touch without the rods’

bodies being in line. It’s touchy work that requires a good eye

and hands, plus know-how, understanding, and judgment.

There will be times when the basic height of the bases will be

level. Still, the front or rear of either the front or back base

can be pointing slightly down or up. Carefully tapered shims

will be required.

Note: To this point, we’re assuming the barrel in the action is

straight and/or not an ultralight model with heavy stock

upward or other directional tension that can actually change

barrel point zeroing. You can witness the effect of barrel

pressure by placing a barrel blank heavy chamber end into a

three-jaw lather chuck and locking it up firmly. Then, with a

bit blank in place, move the lathe carriage and toolpost just


FIGURE 9—The front scopemount’s alignment rod pointis higher than the rear ringrod point. The rear scopebase must be shimmed “up”to level. Windage adjustmentin the rings accommodatesleft-right movement.


touching the barrel muzzle or any other part. Back off the

crossfeed a given number of thousandths and then advance

enough to take up the slack. This puts you in position to

measure the actual amount of spring-out from its natural

position that a mere light or medium finger pressure can

exert.

Now, think about force-locking up a scope in misaligned

rings and/or bases, and realize the force being exerted by

the powerful leverage of screws. The slightest deviation

from a relaxed central position for a scope can cause serious

troubles. I made my scope alignment rods from round plastic

stock. It took less than 30 minutes. Though not a cure-all,

they help in diagnosing trouble-causing scope strains.

Scope Centers Vary

You should be aware that scope centers coming from the fac-

tory aren’t identical. Suppose a scope, mounted with a

Weaver-type, nonadjustable mount, just happened to be so

close that a few clicks of windage and elevation centered bul-

let impact point on the target. Then the second, fourth, or

tenth such identical scope will usually shoot elsewhere when

installed in the same mount on the same firearm in a strain-

free installation. Variation will be even greater if the scope is

held in the rings under strain.

During the post-World War II “scope boom,” even small deal-

ers ordered scopes by the dozens. One midwinter lull-season

customer wanted his 2 1/2 power scope in a nonadjustable

mount replaced with a better-class, higher-powered glass. He

hoped a new mount wouldn’t be necessary. Having about 10

scopes of the type sought in stock, I conducted the following

experiment. I mounted each scope in his rings and carefully

bore-sighted it on his rifle, making notations on each. They

varied from an almost impossible 1 1/2 feet in windage at

50 yards to less than 2 inches. Similar vertical differences

existed.

I went back to the closest one, pleased the customer, and

chalked up the experience to “learning.” This experience also

proved that some scopes could be under strain in the identical

mount that left others relaxed. Hence, we can’t overemphasize

the importance of individual fitting.

Bolt Jeweling with a Drill Press

Jeweling or damascening is an ancient form of decorating

metal. It has a series of overlapping, highly polished circular

spots, usually holding the overlap just short of the swirl

centers, which loom out as jewels in the lengthwise rows.

On firearms, you usually find jeweling applied to rifle bolts,

cartridge followers, ejector housings, and the flats of bolt

handles.

In jeweling, the bolt body may be coated with abrasive com-

pound and the “whirls” made with a special flexible wire

brush. Or, a dry grit-impregnated rubber tip is held in the

drill press chuck jeweling fixture, which must be sufficient

length to clear the bolt handle. No grit compound is used

with the dry self-impregnated rubber tips.

The wire brush system of jeweling is more popular, as after

slight wear, it conforms more closely to the bolt’s contour

and is more attractive (Figure 10). The special wire brushes

have a tendency to flare when the necessary slight contact

working pressure is applied. Special tiny “O” rings, shrink

tubing, and even a shallow nylon thread wrapping around

and next to the mandrel hold the steel bristles at uniform

round diameter. With the drill press running at high speed,

the operator raises and lowers the jeweling tip slightly to

allow the brush surface to swell out and contract slightly.

Fine jeweling with wire brushes depends on the base polish,

your manipulation of the drill press, and fixture indexing.

This is where the value of a compound table shows up. The

table enables you to move your spots progression uniformly

(Figure 11).

Otherwise, you can use a “fence” clamped to the press table

and manually moved for spots locations. Or, you can go the

expensive route and purchase an elaborate fixture wherein

the indexed adjustments are incorporated. As with other

gunsmithing, there’s room to experiment: with jeweling

you use grits, fixtures, and tips. When you’ve finished a job,

thoroughly wash and rinse all jeweled surfaces in cleaning

solvent and air-blow dry inside and out. Then wipe with a

quality light oil.



FIGURE 10—This photographdepicts jeweling with a wirebrush tip.

FIGURE 11—A compound drillpress table gives accuratespacing with a B-Square jew-eling jig. The brush tip in thephoto is thread-wrapped foruniform medium “swirls.”


Self-Check 2

Fill in the blanks in the following statements.

1. The special wire brushes used in jeweling have a tendency to _______ when the necessary slight contact working pressure is applied.

2. Buehler scope mount rings are adjustable via their laminated _______.

3. The _______ method is the most popular type of jeweling.

4. You can’t rely on _______ fixtures for establishing a final zero.

5. Adjustable scope mounts have windage screws that provide adjustment to the _______and _______.



MILITARY RIFLE BOLT FORGING

Altering Mauser, Springfield, and M-54 Winchester bolts

via forging (not welding) isn’t just a matter of turning on

an acetylene torch, heating the bolt, and pounding it down.

That theory has practically ruined thousands of perfect bolts.

Forging (forming metal by heating and hammering) a bolt

properly isn’t easily learned—especially without proper

instruction. Involved with bolt forging from its beginning,

I had to learn by my mistakes; however, in a way I was

fortunate. Experience taught me to correct the mistakes.

Shortly after World War II, I obtained my first set of forging

blocks. I had found it impossible to turn out an acceptable

job by taking my bolts and blocks to the nearest welding

shop and attempting to coach people on heat application.

The forging service I used was far from perfect. The bolts

were pounded down too much, which led to too short a bolt

handle. Sometimes the bolt handle shank base was still too

high to give an adequate clearance for low scope rings and

large scopes.

Longer Bolt Handle Breakthrough

No one seemed to have the answer. The best known gun-

smiths in the nation were sawing off the military bolts and

skillfully welding on knurled and fancy handles and knobs.

Many others clumsily welded on replacements (some only

surface welded) that broke off in the field, causing hunters

to lose game.

My bolt forging efforts were acceptable but still produced bolt

shanks a little shorter than desired. One day, a “mechanical

bell” went off in my brain. Why did I so often get a nicer bolt

forging job from the Mauser straight-handled bolts? There

had to be a mechanical reason. Months of brain scratching

climaxed one night about 3 A.M. when I awoke with a possi-

ble solution! It was so clear, I grabbed a pencil and pad and

made notes for some time. I couldn’t sleep until going to the

shop and trying my idea!

It was simple logic: you don’t pound it down, or forge it

down! The straight bolt handles were vertical as held in the

forging blocks. This made it impossible to pound downward

after the handle was heated dull-red for forging. Therefore,

I forged over and outward, not downward. This was why I

was getting a longer, nicer forged bolt on the straight-han-

dled Mausers. After all, when forging metal, you move it in

the desired direction and in desired proportion. My first effort

turned out better than ever (Figures 12 and 13).

Elated with success, I forged a second bolt, determined I

could move whatever portion of that square-like rectangular

Mauser bolt shank base I wanted to transfer out into addi-

tional bolt handle length. Short length was one of the critical

complaints about average forging when compared to welding

new handles on.

Therefore, why should a bolt handle have superfluous verti-

cal bolt body before going into the outward shank takeoff?

The answer is it’s unnecessary. With the bolt in the forging

blocks held in a heavy steel bench vise, insert the steel bolt

plug to act as a heat sink and prevent collapse or distortion of

the bolt body. Pack any protruding part of the bolt body with

wet asbestos. With a medium-large tip in the acetylene torch,

heat the bolt handle to red-forging temperature (Figure 14).


FIGURE 12—Don’t pound the handle down. Shown is a pitifully short, high-based,thin-shanked, nearlydestroyed Mauser M-98bolt—pounded down, notforged.


FIGURE 13—The straightshank Mauser bolt, left,is eas-ier for beginners to forge thanstandard Mauser (center) andthe U.S. 1903 Springfield bolt(right). All will forge nicely.

FIGURE 14—Shown is a red-hot bolt that’s acetylenetorch-heated at the bend.Acustom form-fitting wrenchlifts the bolt to vertical position.

Warning: Asbestos can be dangerous to your health. You may

prefer to use Brownell’s Heat Stop heat-control paste as a

replacement for asbestos. Heat Stop keeps heat from spread-

ing when welding, soldering, or brazing, and it’s a very good

substitute for asbestos. Also, some gunsmiths who only

infrequently need to control the spread of heat simply use

wet rags to stop it. In this procedure, an assistant repeatedly

pours water onto the rags to keep them wet and cool. As a

result, the rags don’t heat up and ignite from the torch heat,

and the covered metal surface remains relatively cool.

Continuing, I took an 8 ounce ball peen forging hammer and

flexed it in my working arm, ready for fast work. I pounced

on the upper 50 percent of the rectangular Mauser bolt

shank base rapidly with the medium-heavy forging arm and

evaluated the progress. I made sure to apply as much heat

underneath as on top (Figure 15).

Speed is the key to much of your success. Keep the bolt

working, forging, and red-hot. You’ll learn the exact color

from experience. Use the flat side of your ball peen hammer

until the bolt handle leans heavily away from you (Figure 16).


FIGURE 15—This bolt is stillheated red in forging blocks;asbestos-packed, heat sinkinside, the handle is nearlyvertical and ready to forge.Remove the wrench, grab theforging hammer, start fast,and work 50 percent downinto the rectangular base.


Shift to the ball end of hammer and continue to hammer

forward, away from you more than down, working the steel

outward into a longer bolt shank. Keeping the forging tem-

perature perfect and working fast with rapid semi-heavy

hammering will prevent parting of the metal and preclude

any welding fill-in. (Figure 17).

FIGURE 16—We remove thebolt from the blocks for thisphoto to show precisely thelow forging impact area andhammer angle, initially forcingmetal out and away, NOTDOWN! Naturally, you useforging blocks and vises.

FIGURE 17—After forcing the bolt shank to about 45degrees, switch to the ballend, still hammering awayfrom you, at the angle shown,but adding downward force.

Caution: Never resort to a heavier hammer. Excessive-weight

blows can cave in the bolt body under the bolt handle.

Practice and experience will enable you to visually determine

when the shaping is complete (Figure 18). You can do slight

up or down alteration later. You’ll have flare-out of metal

both under the bolt shank next to bolt body and on top of

the bolt shank, near the bolt body. If you performed the forg-

ing properly, you’ll have more than adequate steel to provide

you with required trim-out. If not, practice more.

Upon completing the forging and shaping, retract the torch

flame gradually to protect bolt temper. There should be no

cocking cam edge, melt-ins, or cave-ins, which are common

to welding on new bolt handles (Figure 19).


FIGURE 18—We have the boltout of the blocks to show theDOWNWARD blows and thecenter of the ball in relation-ship to the remaining verticalbase, which is important. It’swithin a few blows of being finished.


If perchance hesitancy and heating circumstances lead to a

soft cocking cam that’s easily cut with a file, no problem.

Return the bolt to forging blocks without the heat-sink cen-

ter. With a wet asbestos plug partway down the bolt body

opening, apply acetylene flame to the cam area until dull-red,

and instantly apply a pack of sloppy-wet asbestos. The cam

area will now be hard enough to resist cutting with a file,

and the temper change won’t extend into undesirable areas.

A properly forged bolt, held in forging blocks and packed

with wet asbestos, with heat-sink installed, won’t allow heat

transmission coloring to extend even into the edges of the

forging blocks (Figure 20).

FIGURE 19—Shown are 1903-A3 Springfield bolts; on theleft, the original; on the right,one completely low-forged andready to trim out and polish.Springfield bolts have moremetal bulk at the shank baseand require more heat and vig-orous forging.

If you or a customer desires a spoon-bill, knurled, checkered,

or other fancy bolt handle, you can safely forge the original.

Then, cut off the original bolt knob two-thirds the distance

out from the bolt body and weld on your new version. In fact,

the cutoff can be anywhere, but leave room to totally heat-

protect the bolt body (Figure 21).

Note: Remember today’s litigious climate; you can’t be too

careful! Use eye, ear, and lawsuit protection! Work carefully!


FIGURE 20—Almost all of the original vertical rectangular bolt shank base was converted to length in this forg-ing job. Note that the proof mark and base outline are still intact. You can learn to do likewise. You’ll amaze yourcompetitors and gain their respect.


The Bench Grinder

Bench grinders are a blessing in modern work areas.

Gunsmiths who can afford them use at least three because

they’re timesaving. One general-purpose, heavy-duty bench

grinder handles everything from Enfield. Another smaller

one, close to the workbenches, is capable of a multitude of

light trimming, shaping, sharpening, etc. The third is equipped

with a cutoff wheel about 5/32 inch face width, the other

wheel around 1/16 inch face. Circumference size may vary

according to your grinders (Figure 22).

Note: It’s 100% impractical to change grinding wheels for

various operations. To run and cut properly, grinding wheels

must be trued (a big job quite often requiring diamond trim-

mers). Removing and reattaching them changes everything.

Warning: Always use safety goggles and a respirator when

working with bench grinders and other equipment that emits

dust, grit, chips, etc.

FIGURE 21—Shown is thelonger, completely trimmed-out,bead-blasted Mauser bolt, with-out welding, pits, breaks, ortemper loss.

In an active shop, grinders, the lathe, drill press, and all little

bench tools are almost always in constant use. When you go

back to trimming out that newly forged bolt, mechanically

inclined gunsmiths can see the flare-outs and forge-overs

that should be ground off. The cutoff wheel on a grinder

enables you to work on the underside of the bolt shank,

where larger wheels can’t reach (Figure 23).


FIGURE 22—Shown is thereceiver bridge grinder spottedfor scope mount holes drilling.A bench grinder with a inchcutoff wheel is ideal to rough-notch a rifle action for a newlyforged low bolt. Use inchdiameter emery tips for accu-rate notch finishing. Theassembled bolt must haveslight up-and-down clearancewith the safety on.

FIGURE 23—This inch facecutoff wheel enables gun-smiths to reach into touchyareas for bolt-forged metal flare removal.


Bench grinders with the wheels from 3/4 inch to 1 inch face

width are also indispensable. You can use them for dainty or

heavy work. No shop can be without them. Keep a smaller1/4 horsepower grinder within arm’s length of your main

workbench. You’ll need it often.

Once you learn to forge correctly, a longer new bolt forging

takes less time than it takes your competitor merely to saw

off the bolt handle. Also, there’s as much cleanup time

required on a welded bolt as there is on a forged bolt. After

all the rough shaping, switch to hand work and buffing

wheels for the final master’s touch.

Grinder-trimming Forged Bolts

With major shifting of metal during bolt forging, you can

expect flare-outs, overhangs, and often some need for thin-

ning, shaping, and smoothing. In such cases you would use

bench grinders with wheel faces of 1/8, 3/4, and 1 inch. A

1/16 inch cutoff wheel to go with your 1/8 inch wheel is often

handy. Frequently, a slight “bellying” of surplus metal occurs

on the underside of the bolt shank, outward from the bolt

body. You can remove surplus metal most easily with the1/16 inch and 1/8 inch face cutoff wheels, as they can reach

into the area. The 1/8 inch cutoff wheel does a good job of

removing the side-flare on either side of the top area where

the forging blows were struck. You can easily trim the top

flat of the forged bolt handle with the larger bench grinder

wheels up to 1 inch (Figure 24).

Next, finish the surface on 1 inch face, felt buffing wheels,

initially treated with #150 grit. Then, use the finer #450

and move on to sailcloth buffing wheels with #450 or finer

polishing compounds and rouge for the final polish. This

also provides better retention of lubricants and antirust

preparations.The Importance of Bench Grinders

The Importance of Bench Grinders

As is evident from reading the first few pages in this unit,

bench grinders are turned on and off more than any other

general shop equipment. As you can afford them, acquire

at least three so that you can keep the wheels trimmed and

balanced, and so that you won’t lose time in making wheel

changes (Figure 25).

The most casual firearm repair often requires a touch on

a grinder. Welded parts have to be trimmed, dimensioned,

and faced off. New gun parts need to be mated to remaining

working mechanisms. Keep a small or medium 3/4 inch

wheel-face grinder within a few arm lengths of your main

workbench. One wheel should be fine grit and the other

medium or coarse, or arrange in accordance with your shop’s

most common demands.


FIGURE 24—You can use alarger 1 inch face emery wheelto grind flat on top of forgedbolts or for a multitude of otherheavier-duty shop uses.


Shop-required Buffing Equipment

Basically, you use buffing equipment to prepare steel sur-

faces on guns and gun parts for bluing. Buffers have grit-

treated wheels of solid felt, 1 inch wide, 6 to 8 inches in

diameter, and loose and stitched muslin wheels. They have

almost daily and hourly additional uses (Figure 26).

After an approximate grind-down of a welded repair, felt

#150-grit and #240-grit wheels offer an ideal and much

smoother finish with a surprising contouring capability.

You can finish lathe bits and chisels for stocking work and

other uses on the buffing wheels. Fine-cut chisels respond to

a delicate application of buffing wheels with grits of #450–500

and down to rouge, provided you learn how to hold them for

proper angle and tension. Sharp tools save time and make

work more enjoyable.

FIGURE 25—Here BillSchumaker gives a final touch-up to a bolt handle. Easyaccess to hand and other toolssaves time in this “U”-shapedwork area.

Figure 27 shows a buffing machine shop arrangement for you

to consider. The shop has the window for light, compressor

in the right corner, a blasting cabinet to the right of the com-

pressor (not shown), and a central stand within easy reach

for parts.


FIGURE 26—Shown is a home-shop welded buffer frame, con-sisting of pipe, eye-beam, andbar stock. Except for one bear-ing replacement, this setup hasbeen in service since the endof World War II. The standingdisc (right side) is a handyaccessory for woodworking andrecoil pad trimming.

FIGURE 27—A Typical BuffingMachine Shop


Buffing barrels and barreled actions require “swing-room,”

especially when getting to the smaller parts. The point isn’t

that you use the buffer that much, but rather that you have

the various grit-size wheels in place when you need them.

Then you can swing from one wheel to the next without

changing and rebalancing. In the progressive shop, many

wheels are in position at once. Going from one to the next is

routine and without delay and problems (Figure 28).

FIGURE 28—This recommendedBaldor buffing machine givesadequate wheel clearance. Ithas an 8 inch diameter 1 inchface felt wheel on the left (sewn sailcloth) and a finalrouge polish wheel on the right.


Self-Check 3

Indicate whether each of the following statements are True or False.

_____ 1. Upon completing forging/shaping, you should retract the torch flame immediately toprotect the bolt temper.

_____ 2. You can use bench grinders with the wheels from inch to 1 inch face width fordainty or heavy work.

_____ 3. Altering bolts is just a matter of turning on an acetylene torch, heating the bolt,and so-called “pounding it down.”

_____ 4. When forging metal, you should move it in the desired direction and in desired proportion.

_____ 5. To run and cut properly, grinding wheels must be trued, a big job often done withdiamond trimmers.



DIAGNOSING AND CORRECTINGCARTRIDGE FEEDING PROBLEMS

Gunsmithing is a highly technical trade, and no one aspect

of it takes precedence over another. The safety factor and

correct chambering and headspacing during barreling are

very significant, as is proper function. Earlier study units

stressed that no matter how great the firearm might look,

if it fails to function correctly (unless it’s a collector item)

it’s probably worthless.

Cartridge feeding problems are a major cause of firearm

malfunction. Factory arms aren’t immune to cartridge feeding

problems, but the biggest headaches arise from military

conversions. Problems arise when actions designed for one

size military cartridge are forced to accept modified case

shapes and bullet diameters. I’ve been performing military

conversions since the end of World War II and I’ve spent

years diagnosing various problems. The following information

should help those who try their hands at military conversions.

Mauser 8 mm and 7 mm cartridge cases have slightly less

diameter at the front shoulder than those commonly convert-

ed to .30–06 and .270. This results in a “pinch” between

the rails of some actions at the front end. This occurs when

cartridges attempt to rise and get into line for the bolt to

chamber and close on a round. (Eventually, some width of the

restricted rail sides might have to be removed, but not yet!)

Note: Often the cartridge case bases won’t ease up into the

bolt face under the extractor, which is a must. You must

deal with this problem before doing any further work. If too

much resistance exists for the cartridge case extractor groove

to get the extractor claw to slip into it comfortably, heavy

contact areas on the frontal rails are still off-limits for altering

via grinding.

Actually, resistance often leads to a “lucky” situation. It’s

easy to remove a microscopic amount of metal from the

extractor claw face with a felt-gritted bob in a hand grinding

tool (Figure 29). Work with extreme caution. The extractor

claw contact to case has a slightly rounded contour to match

a tiny flat surface at the bottom of the extractor groove of the

cartridge case.


However, far too many extractor claws are sharpened care-

lessly to a knife edge. This seems to be characteristic of some

modern Mauser-type actions. Some have sufficient tension on

the cartridge case-to-bolt-face shroud that the tiny required

flat can be created via the gritted felt bob. Believe me, it’s

this critical! A sharp knife-edge extractor claw face is neither

fully functional, nor is it desired for longevity in feeding effi-

ciency. The extractor claw should match the extractor groove.

It will grip better and wear indefinitely.

Another important factor is the slight hump on the lower

edge of the extractor claw. The hump is often too severe in its

tension contact against the cartridge case when it must slide

into the bolt face (under the extractor lip). The across-the-

bolt-face opposing resistance surface is the lower edge of the

bolt face shroud. Usually this has too sharp a corner, which

was left by the original manufacturing milling. Gently hone it

down with an EZE-LAP diamond hone and stone in medium

and then fine surfaces. Be sure not to overdo this. The high

point of the shroud circumference must remain only slightly

rounded and smoothed (Figure 30).

Let’s go back to the extractor. This is where you must work

out and finalize the tiny dimensional and tension factors.

First, note how much tension is on the cartridge case rim

from the extractor when a cartridge head is in the bolt face.

The bolt face and extractor should hold a loaded cartridge

when the bolt is horizontal with the extractor on the bottom

side naturally holding the rim against the bolt face shroud on

40

FIGURE 29—This cone-shaped#240 grit-treated felt bob canmatch the radius of an extrac-tor lip with a knife edge that’stoo sharp. Polish back ONLY,and VERY SLIGHTLY if the claw edge exerts too muchtension for easy cartridge headentrance into the bolt face.


top. There must be enough resistance here to hold the car-

tridge in position if it’s extracted, loaded, from the chamber

to be ejected. Tension must not be so light that the cartridge

drops onto the magazine top or other cartridges in the maga-

zine.

This is indeed a touchy adjustment. If you master it, your

customers will love you (provided they’ve experienced other

maladjusted bolt-action feeding problems). Getting this fairly

heavy “springy” Mauser-type claw extractor into a maximum

functioning-with-ease capability is almost a high-tech preci-

sion job.

If the extractor claw-to-cartridge-rim-recess tension is too

heavy, you’re fortunate. It’s easy to remove metal, but impos-

sible to add it onto these tiny surfaces.

The most efficient method of backing off the usually wrong

knife-edge extractor claw-face edge is to select a gritted felt

bob of approximately the same diameter as that of the

extractor groove. Remove the extractor from the bolt and lock

it up gently between the protective jaws of your workshop

bench vise. With the felt bob (about 240 grit) mounted in a

small electric hand tool, angle your vise so you can reach the

claw while you use the bench for support. A mere touch can

often do the trick.

FIGURE 30—If necessary, youcan grind the groove behindthe extractor claw and itsguide lug a touch deeper toprovide more extractor tension.DON’T let the grinding stonetouch the extractor claw.

The curved gripping face of the extractor claw should never

have a knife-sharp edge to begin with. A flat face to approxi-

mately match the width of the cartridge case recess is also

incorrect, as brass varies according to size and manufacturers.

For example, a .223 Remington rim-bottom extractor-grip-

ping flat is only about 0.025 inch wide, while a Remington 6

mm goes to about 0.036 inch, and the 6 mm Remington B.R.

is at 0.058 inch. Measure them yourself for your own

satisfaction.

The fact is, you don’t need a knife-edge Mauser-type claw

extractor. It’s stronger and more efficient at about 0.025

inch. When you reinstall the extractor claw onto the bolt to

test the cartridge-into-the-bolt-face tension, it may still seem

too heavy—yet dimensions appear close.

In this case, remove the extractor from the bolt again, lay it

on a firm material such as plastic or rubberized vise jaw

inserts, and thump it firmly with a hard rubber hammer.

You may have to use several blows to get a desired slight

relaxation of tension into a husky extractor. It’s a time-

consuming tinkering job, but you’ll be proud of the results.

Whipping Knife-sharp Extractor withoutTension

What do you do if you get a knife-sharp extractor claw with

insufficient tension that drops cartridges and cartridge cases

before reaching the ejector? This is quite common on some

imported new Mauser-type

rifle actions. First, write or call the supplier and complain

long and loud. Then ask for some replacement extractors

from which you can hopefully select one that fits properly or

has sufficient tension to permit modification.

The only other solution is to somehow alter the surfaces

under the extractor where it bears against the bolt body.

Here, you remove a few thousandths of an inch from the

inside of the extractor groove directly to the rear of the claw.

This part of the extractor bears against the bolt shroud head,

with its extractor fore-and-aft positioning lug running in a

groove milled into the front of the bolt just forward of the

lugs (Figure 31).



Use a diamond wheel dressing tool to bring an emery cutoff

wheel to the approximate diameter of the bolt body front end

just behind the shroud. Then, trim out an accurate radius to

permit the extractor claw corresponding tension increase

Warning: Don’t trim out anything on the thin part of the

extractor inside that rides over the right locking lug of the

bolt. Here, no dimensional reduction is safe.

Again, all the alterations and adjustments are time-consuming,

tinkering jobs, the accomplishment of which anyone can be

proud. Mauser claw-type extractors weren’t designed to safe-

ly override bolt closures on cartridges just dropped into the

chamber. At times, such a forceful closure will break off the

extractor lip.

Don’t single-load or crowd that extra round into the chamber

over a loaded magazine. You can safely get that last round

loaded using common sense and manipulation. Place it on

top of the loaded magazine and push down. There’s usually

some slack left. With the bolt open, and while holding down

the round, slip the bolt forward easily and pick up the car-

tridge rim under the extractor, move the bolt forward, and

chamber it. Be sure to have the rim under the extractor

when you forward the bolt. There’s “Nuthin-to-it!” except

remembering to do it right!

FIGURE 31—The extractor clawshould exert sufficient tensionagainst the opposing bolt shroudto easily hold the weight of aloaded cartridge, yet permit easyentrance into the bolt face underthe extractor.

Emergency Alteration

If you’ve followed tension and other tolerances carefully,

you’ll know that you should bevel the forward outside edge of

the extractor claw. Without severe extractor claw tension, the

extractor will almost always override the cartridge rim when

the bolt is closed onto a round that has merely been dropped

into the chamber and the bolt closed. However, don’t push

your luck—do it correctly—and then hope you save the

extractor if you do make a mistake and let one slide into the

chamber ahead of the extractor.

Modern, within-bolt-shroud spring-type extractors such as the

Remington M-721, 722, 600, and 700, have spoiled folks on

closing their bolts on chambered rounds. This increases the

possibilities of doing it wrong on the old M-70 Winchesters

and other rifles that have Mauser claw-type extractors. When

you get into the gunsmithing business, keep this in mind

and inform your customers.

Action-rail Tolerances

If you’ve whipped your first extractor-bolt-face alteration, you

can rejoice only for stage one. However, without success in

the first stage, all other efforts are almost in vain. Go slowly,

and think!

Now that nothing prevents the cartridge from properly entering

the bolt face, observe the cartridge as it rises up (or attempts

to) out of the magazine. Getting the cartridge’s semi-rimmed

head to easily (and with proper tension) slide up into the bolt

face was all conducted out of the rifle action. Rifle action

imperfections and variations could wrongly influence your

work.

Next, with only the bolt body and extractor in the action, try

feeding cartridges. Observe whether or not there’s excessive

resistance to the cartridge coming up out of the magazine

front. Often, left and right action rails require a slight trim-

out around their front areas to relieve binding from a new

larger cartridge as it’s pushed forward and up by the bolt

(Figure 32).



You can expect such a situation when a military or other

action is barreled to a larger caliber or cartridge. If the car-

tridge body is longer in its full diameter, you must grind out

the section under the top rails’ edges to accommodate it for

any additional length and/or width.

Note: Almost no dimensional criteria for the above task exist.

Trial and error and experience prevail.

It doesn’t matter how careful you are. Here again, you face

the possibility of mistakenly removing too much metal and

having no way to put it back!

The topic of action-rail tolerances came up during a visit with

one of the world’s best known “all-around custom gunsmiths.”

He responded, “After you’ve worked your heart out, are sure

you have everything right, load the magazine, close the bolt,

and watch all the rounds jump out onto the ground when

you open it, you know you’ve gone too far!”

Most problems arise from not doing the aforementioned

extractor altering and careful fitting first, plus carelessly

widening those top rail lips, which initially you shouldn’t

touch. (Only observe the top rail lips for adequate left and

right clearance for the cartridge body to rise up out of the

magazine, as its rim gets under the extractor.)

FIGURE 32—Emery stones, in3/16 inch, 3/8 inch, and 1/2 inchdiameters are a good combina-tion for slight widening ofbetween-the-rails gap andextending the chamber approachhump for longer magnum car-tridges.

Keep in mind that cartridges aren’t supposed to emerge from

the magazine until the bullet, neck, and shoulder are started

into the chamber with the bolt pushing it forward and the

rim getting up under the extractor lip (Figure 33).

It’s difficult to discuss, write, or illustrate all of the details of

successful cartridge feeding alterations. As you study this,

remind yourself: “Don’t grind on those rail edge lips” until

you’re positive it’s required. Then grind only along the front

1 inch of the action’s magazine opening and directly above

the front 1 inch of the magazine box.

Note: Work should progress very slowly at this point. Feed

loaded dummy cartridges out of the magazine after every

slight grinding

or even polishing at front rail edges and observe whether or

not the bullet-neck front end is being pointed at the chamber

opening. Also, check whether or not there’s too much bind or

friction against any portion of the front of the cartridge body.

Excessive rubbing will leave a telltale brass smear on the

inside of the action front rail area.

Caution: Don’t always remove more metal where contact

exists. The narrower front of the cartridge body humps on

left and right rail insides. It must guide the round properly

into the chamber, along with the correct position of the case

base in bolt face and the rail sides in front of it. Strive for a

fitting that allows forward movement of the round into the


FIGURE 33—The .338 Magnumcartridge shoulder is 6 mmlonger than 7 and 8 mm for M-98design. For comparison, the.30–06 is also too long. Use anelectric hand grinder with a 7/16inch �� 3/4 inch emery stone toextend between rails, width for-ward. (Don’t touch the top rails’lips now.)


chamber with moderate nonbinding pressure. This takes

time, study, application of all you know, and learning.

Correcting Cartridge Jump-outs

You may be able to save the action, if you haven’t gone too,

too far! Grind out a little more under the rail lips, thus giving

more lip overhang to hold the cartridge body. Don’t touch

the rail lips, as apparently they’ve already been ground off

too much!

I ground too far once with a .35 Improved Whelen wildcat

cartridge on a 1903 Springfield army action. This much fatter

(most of the body taper removed) case caused serious feeding

difficulties. Eventually diving onto it with a vengeance, I went

too far and got jump-outs! Gradually widening the area

under the rail lips saved the action. The widening allowed

the “fat” rounds to be fed so perfectly we could even load the

magazine with fired empties and feed them into the chamber

without hang-ups! Much was learned from this bad, then

lucky, experience. (Use fine-grit felt bobs to polish surfaces.)

Influential Magazine FollowerDimensions

You can experiment with cartridge follower dimensions via

adding small layers of soft solder and at times epoxy, then

testing. This enables you to decide on changes without

experimental welding to scar up or wreck a perfectly good

follower. You remove solder or epoxy and add welded steel if

you determine that it’s warranted.

Even a slight pinch-together of the top of the magazine box

changes cartridge feeding, as does a bit of spreading the top.

There’s a lot of work, study, and experimenting to do before

you become a master of cartridge feeding alterations. But it

will save you many headaches and extend your reputation

into far corners, besides earning you some money.

Wrong Feeding Diagnosis on MilitaryKrag Rifle

I had a .30–40 bolt-action Krag rifle with the magazine car-

tridge feeding cutoff removed. This left a partial cylindrical

opening in the bottom of the bolt-way. The bottom edge of

every cartridge rim would catch down into this and hang up

as the bolt was pushing it forward. The front bullet end of

the round would be tipped down firmly against the bottom of

action chamber approach area.

Someone had done useless, unnecessary grinding at the

chamber approach bolt-way bottom, damaging the action

because of a 100% wrong diagnosis. The proper repair con-

sisted of merely lathe-turning a small steel rod the exact

diameter of the Krag rifle’s cartridge cutoff shank. I then

ground it to conform to its original “on” position shape, and

staked it into position with a few center punch dimples on its

blind side. Think, and go carefully. Accurate troubleshooting

is one of the gunsmith’s greatest attributes.



Self-Check 4


1. _______ in inch, inch, and inch diameters are a good combination for slight wideningof the between-the-rails gap and extending chamber approach hump for longer magnumcartridges.

2. It’s easy to remove a microscopic amount of metal from the extractor claw face with a_______ in a hand-grinding tool.

3. Some modern Mauser actions suffer from _______ that have been sharpened carelesslyto a knife edge.

4. Some new, imported Mauser-type rifle actions have a knife-sharp extractor claw, with_______ , that drops cartridges and cartridge cases before reaching the ejector.

5. An extractor claw should exert sufficient tension against the opposite bolt shroud to easily hold the weight of a _______ , yet permit easy entrance into the bolt face, underthe extractor.


THE LATHE: KING OF GUNSMITHING TOOLS

• Uses for the lathe are endless:

• Making the tiniest screw

• Facing of sears and working parts accurately with a tool

post grinder

• Rebuilding surfaces

• Opening bolt faces for larger cartridges

• Making firing pins

• Cutting dovetail slots with your milling attachment

• Threading, chambering, and fitting new barrels (Figure 34)


FIGURE 34—Shown is thelathe, the shop’s foremosttool. Steady rest is a necessityfor threading between centersand chambering.


A Barrel Vise

A heavily built, solidly mounted barrel vise is a must for

removal and proper installation of new barrels, or others

removed when improving chambers. Don’t make the mistake

of anchoring a barrel vise to wooden benches or walls. Pour

a concrete pillar or heavy rectangular base through your

building floor into the ground. Set your mounting bolts into

the new wet concrete through an approximately 1/2 inch �

7 inches � 10 inches steel plate, in position to mount the

vise over the protruding bolts after the cement cures. This

arrangement will last forever and never tear out walls, tip

over, or break benches. Mine is on a concrete block 17 inches

� 20 inches � 32 inches thick. No barrel removal has ever

defied it (Figure 35).

While my vise is a Vickerman, it resembles the Brownell’s

THREE-V in both vise and wrench. Hardwood and lead barrel

sleeves have often failed me. Steel seldom gives a perfect to-

the-barrel fit and scars the barrels. I use a mixture of bullet

lead and bearing babbit, which is harder. By fitting a pair of

wooden slats to the flat sides of the bottom half of the vise,

the barrel is inletted to rest slightly above center, so the

sleeve halves will have cinch-up space.

FIGURE 35—You’ll get trouble-free barrel removal and instal-lation with the heavy barrelvise anchored in concrete.Precast fitted barrel sleevesgive positive grip. The 8 poundlead hammer is shop-cast.


After you plug the vise cinch-up screw holes in the bottom

half, pour the molten metal into the lower vise half around

the barrel. You might have to do several practice pours

before the sleeve half cast will shape up properly. Be sure

to position everything identically for your second-half sleeve

pour. This assures a perfect fit. Initially, you should position

the barrel as near to the receiver as possible. This provides

more grip area and more rigidity.

The best sleeves are made from a metal mixture that gives a

slight ring when gently tapped with a steel tool. Use your

metal stamps to mark the sleeve set. (Examples: #3 Shilen,

Douglas #4, Springfield, Enfield). This saves much time later.

File the sleeves neatly near the barrel vise. A space, 11/2 �

21/2 inches, provides ample room for drilling to accept an

empty G.I. .30–06 case as a station peg. Each 17 inches of

this rack holds 10 sleeve sets with their rubber band keep-

ers. The racks are strapped to the chimney with stovepipe

wire to provide an easily removable no-drilling arrangement.

This system provides you with perfectly fitting, readily avail-

able barrel vise sleeves. Never make a nonfitting sleeve set

to remove a different barrel. Take time to cast a perfect set.

Add it to your tools, to be there next time you need it.

Note: Eventually, you’ll need a Kleinendorst Remington M-700

action adapter tool for removing the round Remington actions

with that separate recoil lug, which can’t otherwise be kept

aligned. Frequently, it’s necessary to improve the gripping

onto the action by using rosin or sheets of emery cloth.

Gunsmith-built Action Wrench Hammer

The 8 pound lead hammer in Figure 35 has a 22 inch handle

of scrap 7/16 inch pipe. Initially, I drilled several cross-holes

through the head end and then positioned it inside an empty

food can, which served as a casting form. It’s easy to recast a

new hammer head when one gives out. Some gunsmiths use

long-handle extensions for their barrel wrench, and you

might even proceed to precision torque wrench cinch-ups for

fine accuracy work. Remember, gunsmithing-inclined folks

are among the world’s most inventive people. You can make,

fashion, and improve many of the gadgets and tools you’ll

need and use.

52


The Complete Shop

As financial considerations allow, you’ll need more than a

good lathe, barrel vise, and action wrench hammer. A “com-

plete” shop requires a drill press, bench grinders, electric

hand grinders, acetylene and electric welding outfits, several

buffing machines, and a vast assortment of hand tools. An

air compressor, blasting gun, and a long-gun size blasting

cabinet for glass bead treatment of firearms prior to bluing

are modern frontline essentials. You’ll be adding more tools,

respirators, eye goggles, and gadgets the rest of your life!

Details of a Barrel Fitting

Instead of chitchat generalizations that can confuse and

dampen your lust to start real gun work, let’s follow a barrel

installation. Prior to attempting this task using a lathe,

you should complete a basic course in lathe operation and

metalworking. Gun barrel fitting has intricacies of its own.

We’re working with thousandths of an inch. Errors can be

dangerous.

To perform accurate work on a lathe, you must mount the

lathe firmly on a heavy metal or hardwood timber bench and

bolt it to a concrete floor or into the ground support pillars.

You must level the bench top and lathe with a machinist’s

level and recheck it frequently. My machine is a Sheldon

XL 56 with a 13/8 inch hole in the spindle, approximately

36 inches between centers. It can handle 54 different threads

(feeds), but none metric, which modern gunsmiths may need

and should consider purchasing.

Numerous quality chrome-moly and stainless steel barrel

blanks are available from reputable barrel makers. They

range from lightweight through heavy-target contours offer-

ing various rifling twists. While we can’t settle the proper

twist controversy, it’s almost entirely related to the weight

and length bullet used. Ed Shilen, of bench-rest-shooting-

barrel manufacturing fame, said of the 6 mm, “If you plan to

use 68- and 70-grain target bullets, get a 1-in-14 inch twist.

A 1-in-12 inch twist stabilizes 75 to 85-grain projectiles . . .

and if you want a 100-grain bullet hunting rifle, it requires a

1 in 10 inch twist.”

Data for proper twist selection of your barrel blanks is avail-

able from many sources and is a must for every gunsmith’s

bookshelf. It’s usually impractical for the average gunsmith

to stock heavy blanks and turn them down, as manufacturers

have superior equipment to handle this and provide a contour

selection that’s more than adequate.

Removing 11/2 Inches from the Muzzle

Due to slight internal muzzle damage possibilities during

manufacturers’ turning of barrel blanks, I cut about inches

from the muzzle. Then I face off the heavy breech end to at

least the outside thread shank diameter of the barrel I’m fit-

ting. A chamber cut on this end of the barrel removes any

imperfections that might exist near the blank end.

My system of threading and chambering between accurate

lathe centers requires the use of piloted center drills to recut

new working centers. You grip the breech end of the barrel in

an accurate three-jaw chuck and use a floating toolholder or

tail stock center metal pad to allow the piloted drill to follow

its center. After you cut the breech new center, switch ends

of the barrel in the chuck using a slightly compressible cir-

cumference shim on the small end of the tapered muzzle to

better grip and center it. Use the lathe in back gear (slow

speed) and proceed

as you did with the

first center cutting

(Figure 36).


FIGURE 36—The three-jawchuck holds the barrel forcutting a new center with a piloted center drill in afloating toolholder.


Setting Up the Barrel between Centers

Replace the head stock chuck with a head stock center and

faceplate. Then, affix the lathe dog to the muzzle end of the

barrel. Next, position the live tail stock center in place of the

floating toolholder or tail stock thrust pad. Place the barrel

blank between lathe centers and position your steady rest

slightly forward of the barrel’s first large-diameter taper, lub-

ing barrel and center rest bar surfaces with high-viscosity

grease.

Prior to steady rest positioning, you must move your tool

post unit between the steady rest and tail stock. At this

point, I advise you to take a slight truing cut on the large

breech section of the barrel. All barrel blanks aren’t perfect

here where the steady rest must be moved for perfect cham-

bering after threading.

After the large breech end of the barrel blank is turned true,

the barrel shank, can be turned down to length and proper

diameter for the action you’re fitting it to. If the original bar-

rel shank thread was slightly loose in the action, the new

shank can be about 0.003 inch larger in diameter.

Set up your threading bit in the tool post (sharpened and

checked for shape and center). Set the compound at 29

degrees. Follow normal threading procedures, advancing

your cuts on the compound, from 0.001 to 0.003 inch per

pass. Then, return the crossfeed to your starting pass to

zero each time before dropping the half-nut lever for another

pass cut.

Caution: Don’t practice threading on a first barrel fitting.

You need some manual dexterity to accurately time the lifting

of the half-nut lever and swing-back of the crossfeed at the

instant the threading bit nears the barrel shank shoulder.

Watch your compound advance figure as you cut several

thousandths each pass. For instance, the double depth of

the 16 threads per inch (TPI) thread of a Remington M-700

is 0.081 inch.

As the thread approaches a “V” and the depth advance figure

gets close, stop the lathe, back off the tail stock, and try

turning the action onto the barrel. With the action started

onto the barrel shank, advance the cut only 0.001 inch at a

time, trying the action after each cut. After the action will

turn about halfway up the shank, mark with chalk the lathe

dog leg position on the faceplate so you can return it for

more threading, if necessary.

Remove the barrel from the lathe, lock it up in the barrel

vise, affix the action wrench to the action, and carefully

work the action onto the high-viscosity-greased barrel shank.

Usually you can hand work the action onto the new thread,

providing a snug fit and better accuracy. If you can work the

action onto the barrel shank, remove it from the barrel vise

and return it to the lathe. Then, take another slight cut or

two (provided you’ve marked the lathe dog leg position on

the faceplate, and have been careful not to move the dog

during your barrel vise work).

Reaming Chamber

After assuring yourself that you can turn the action onto the

barrel shank, return the barrel to the lathe between centers

and dismantle the threading setup. Then, move the steady

rest rearward onto the trued heavy chamber end of the bar-

rel, just forward of the thread shank. Replace the tail stock

center with floating toolholders or a pad for chambering

reamer feeding. With the lathe still in back-gear, start with

a roughing reamer, using cutting oil and feeding slowly.

Alternate use of the finishing reamer frequently to keep

the reamer pilot in a guiding position in the bore. Clean

chips from reamers at every 1/8 inch advance.

There’s a convenient system for following chamber depth

to correct headspace as you ream. Insert the correct caliber

headspace “GO” gauge into the original barrel and measure

its protrusion with a depth gauge (Figures 37 and 38).

As the GO gauge protrusion nears that of the original barrel,

back the tailstock off and turn the action with the stripped

bolt onto the new barrel shank.

Note: Carefully wipe out the chamber and section of the bore

in front of it prior to each check with the gauge.



With the gauge in the chamber and the action turned up

snug, any gap remaining between the barrel shank shoulder

and the front face of the action is the depth you must yet

ream to reach correct headspace. If you still have a little

gap left here, ream in almost microscopic stages, advancing

the tailstock feed so slightly as to barely get feel-in-chamber

FIGURE 37—You can compareshank length plus GO head-space gauge measurementwith the original barrel, aschamber reaming nears com-pletion. Keep this measure-ment, and keep checking thenew chamber you’re cutting.

FIGURE 38—Use a depthmicrometer to check shanklength of a new barrel for M-700 Remington. Keep the toolpost and bit in position untilreaching the final dimension.


contact. Allow the lathe to turn about 5 seconds to be sure

all cutting is cleared at that advance. Now, clean the cham-

ber and try turning the action all the way onto the shank

shoulder.

If it goes, try the “NO GO” gauge. If the action goes all the way

with the bolt closed and the NO GO in the chamber, you

have correct headspace only theoretically. This is because

when you transfer to the pressure of the barrel vise cinch-up,

head length will reduce by at least an average of 0.002 inch.

So, before you take your almost-barreled action to the barrel

vise, you’ll likely need another scrape-cut in the chamber.

Barrel Vise Cinch-up

If the bolt closes on the GO gauge and won’t close on the

NO GO after a solid cinch-up in the barrel vise, you’ve just

completed your first touch rebarreling job. Sometimes the

cinch-up gains enough so the bolt won’t close on the GO

gauge. In this event, take the barrel back to the lathe for

another dainty chamber scrape-cut. Don’t attempt to hand-

ream when the barrel and action are locked up in vise sleeves,

as the power of these screws is mighty. The chamber is actu-

ally slightly compressed, and reaming will take excessive

cuts, with the possibility of leaving the chamber out-of-round

once the tension releases. Naturally, you remove the action

before going back to the lathe.

Over-reaming

Getting a chamber too deep, permitting bolt closure on the

NO GO gauge, does happen now and then in spite of all

caution. This requires further lathe work, facing off the

overdepth amount of the chamber from the barrel shank

shoulder and also the rear face of the barrel. Then, you

must rechamber the rear chamber edge.

Shop Methods Differ

Some gunsmiths might question whether tight-thread and

precise barrel fitting are necessary for ordinary sporting pur-

poses. It can certainly do no harm, and precision-wild bench

rest gunsmiths and shooters have proven to the world that

58


every minute detail makes a difference.

Another method of handling a barrel blank for threading

and chambering is through the head stock spindle hole and

chuck with a centering device on the left end of the spindle

hole. Use a dial indicator to adjust the barrel to dead center.

Barrel Shank Specifications

The February, 1962, issue of the American Rifleman magazine

(pages 28 through 30) has a “barrel threads” specification

display that gives standard dimensions and thread data for

50 different guns. This valuable addition to any gunsmith’s

library provides much-needed information when you don’t

have an action or barrel to copy. I’m told the list has been

updated since 1962 to contain even more thread specifica-

tions. The 1962 edition serves me just fine. You could find

out more about later updates by contacting the magazine.

Stainless Steel vs Chrome-moly Barrels

Chrome-moly vs stainless steel barrels sends me seeking

information from the barrel makers and the competitive target

and bench rest shooters. These men and women wear out

more barrels than most sportsmen users own. From the

accuracy standpoint, Ed Shilen, a long-time barrel maker and

bench rest competitor, told me there’s little accuracy difference

between stainless and chrome-moly. The problem is that

many different alloys are being used, and even more were

tried in the past. Ed says his experiences with the best

grades of stainless #416 and a special chrome-moly 4140

show a gilt-edge accuracy loss at 600 to 800 rounds for

the chrome-moly. Stainless can go to 2,000 to 3,000 rounds

in the smaller bench rest calibers. In larger calibers, the

stainless lead decreases to about 25 percent, with suitable

hunting accuracy going far beyond this for both steel types.

For average gun owners, the chrome-moly price isn’t nearly

as high as the stainless and is therefore often preferable.

However, stainless is easier to clean, won’t pit or rust, and

machines more easily at the gunsmith level.

Shop Tips

Don’t hurry. Plan your work in detail. An instructor once

told me, “If you have 10 minutes to do a problem, take seven

to figure out how to do it, and take three to do it.”

Provide yourself with good tools. Consider spiral-fluted,

removable pilot reamers for as much of your chambering

as possible (Figure 39). The removable pilot feature permits

you to exchange pilots for doing fine work.

Caution: A slightly loose pilot won’t guide the reamer perfectly,

and one that’s too tight may scar the surface of the lands.

Barrel maker Shilen says his 6 mm barrel bores are running

0.236 to 0.237 inch. Bench rest folks usually prefer the tight

bores. Your regular 0.237 pilot won’t do this job. A pilot

selection enables you to get at it immediately.

Keep all your equipment in excellent condition, lubricated,

sharpened, etc. When chambering, don’t forget to remove

reamers from the chamber and clean chips from the reamer

and chamber at every 1/8 inch advance and then after each

touch on the final approach to correct headspace.


FIGURE 39—Spiral-flutedpiloted chambering reamers(center) provide outstand-ing performance. Pilots prevent possible scarring of bores.


Self-Check 5


_____ 1. To do accurate work, you must level the bench top and lathe with a machinist’slevel.

_____ 2. When replacing barrels, if the original barrel shank thread was slightly loose in theaction, the new shank can be about 0.020 inch larger in diameter.

_____ 3. Spiral-fluted, removable pilot reamers are helpful for chambering barrels.

_____ 4. Generally, stainless-steel barrels demonstrate a gilt-edge accuracy loss much morequickly than chrome-moly barrels.

_____ 5. You need a heavily built, solidly mounted barrel vise to remove and properly installnew barrels, or other barrels removed for chambering.


BOLT FACE OPENING (MANGUMIZING) IN THE LATHE

Shortly after World War II, surplus military bolt-action rifles

flooded the market to end a five-year shortage of hunting

and sporting arms. It was also a time when the Weatherby

belted magnum craze hit the nation. Few gunsmiths had the

tools, equipment, and know-how to do bolt face magnumizing

properly.

To magnumize properly, you of course need a larger cham-

ber. You enlarge the diameter of the bolt face 0.063 inch to

0.065 inch and grind off the extractor lip accordingly while

holding the proper shape and tolerances. Most of the larger-

belted cartridges require magazine lengthening and grinding

away some of the lower locking lug’s backup metal. You need

to grind out and shape the feed rails of the action to accom-

modate the fatter cartridges. A lot of careful metalwork is

involved, and it’s often said that anyone capable of doing a

good job on one of these conversions could do anything.

World-known gunsmiths Al and Roger Biesen, Spokane,

grinned wryly when stating the following. “When you think

you’ve finished your job, gently load three or four rounds into

the magazine to test the feeding. Close the bolt . . . and when

you open it sharply all rounds jump out of the magazine,

alas-plus, you’ve gone too far!”

Sometimes you can avoid ruining an action by undercutting

or grinding a little more off the heavy part of the rails above

the magazine box, but being careful not to widen the top thin

edges. This part of the conversion requires a lot of time and

advance study of factory-built actions that do feed.

Selecting military actions for magnum conversions isn’t easy.

The safety factor must have first consideration, and depend-

able information on the foreign actions (many built with slave

labor) is almost nonexistent.

Fortunately, most gunsmiths are aware of those below

800,000 numbered case-hardened, low-carbon steel U.S.

Springfield M-1903 actions. All but a few of the couple hun-

dred finals utilized single heat treatment, where most of the



problems resulted from irregularities. The irregularities caused

the case hardening to go all the way through, making them

brittle and sometimes highly dangerous even with normal

.30-06 loadings.

Such actions were followed by double heat-treated actions,

which gave additional strength and were considered adequate

for ordinary use (but not for modern magnumizing). The con-

version of number 1,275,767 Springfield Arsenal to nickel

steel WD2340 provided a healthy safety factor. Rock Island

changed to double heat treating in 1927 with number

285,507. After 319,921, they used both the original class C

steel, double heat-treated, and nickel steel. When the barrel

is removed from the receiver, you can see the letters NS

stamped on front of the receiver.

While the better Springfields make up into fine sporting

rifles, and many have been magnumized, the danger is readi-

ly apparent. Most of us don’t recommend higher-pressure

cartridges in them. The 1917 Enfields of Remington and

Winchester manufacture have been used for all types of

magnumizing, but the Eddystone, made in the USA to British

specifications, is extremely hard and difficult to drill and tap.

It’s a “no-no” for magnums.

German and other manufactured Mauser M-98s range from

soft as a .22 L.R., to good and tough. Accurate information

relative to metals, treatment, and safety is difficult to obtain.

Many Mauser M-98 actions have been heat-treated again

and made into fine sporting rifles. Even a Rockwell hardness

test isn’t a strength guarantee, as no one is certain of the

metallurgy.

Through the years I’ve drilled, tapped, and rebarreled hun-

dreds of Mauser M-98s to standard calibers. I selected actions

for quality in a nontechnical, not-recommended manner

(though I’m certain it has some merit). I always drilled and

tapped the actions first. If they drilled and tapped easy-soft,

I rejected them. If they drilled with some evident toughness

and the taps had to be ultrasharp and be used carefully,

I okayed them. There were no headspace setbacks on the

ones I thus converted. I also didn’t overload! Basically, you’re

on your own with military actions. No one can be sure.


You need a tool post grinder, larger and more rigid than the

Dremel Moto tool types, to open bolt faces (Figure 40). Mine

is a Dumore and other makes of the same size are available.

A grinding stone no larger than 7/16 inch diameter by about3/4 inch new length is more rigid than shorter ones. It can

be chucked close, supporting nearly all of the mandrel. A

grinder with little to zero end-play is necessary for accurate

work. Dress the stone to give a sharp front corner edge and

have straight sides with a dressing brick or diamond dresser.

Setting up the bolt in the lathe calls for an inside-the-bolt

threaded center plug to replace the bolt sleeve as snugly as

possible. I originally made mine with a lathe for Mausers,

Springfields, and Enfields. Now you can use Brownell’s heat

sink plugs by merely cutting a center in the outside end if

you’re going to use a lathe dog. Otherwise, grip the bolt rear

end with your three-jaw chuck, somewhat gently to begin with,

while positioning the tailstock center into the bolt face firing

pinhole. Then, tighten the head stock chuck. Position the

steady rest directly behind the bolt lugs. Thus gripped with

front end centered in a steady rest, back off the tailstock

center and move the tool post grinder into position. Carefully

center the grinding stone in the bolt face with only touch

contact, as you don’t want to deepen the bolt face (Figure 41).

FIGURE 40—Keep a toolpost grinder’s emery stonedressed frequently and itscorner sharp.


The lathe should be in back-gear (slow). You should mount

the tool post grinder bracket at 90 degrees so you can use

the compound to keep a wearing grinding stone onto the bot-

tom of the bolt face. After turning on the lathe, move the

cross feed so the grinding stone (with grinder running) barely

touches inside the bolt shroud. Allow the grinding stone to

grind clear before making easy additional feed advances. It’s

touchy, so be careful!

Note: Keep close measure on your progress and back out

the grinder frequently to redress the side of the stone. This

keeps its corner sharp enough to grind a clean right angle

at the junction of the bolt face and shroud bottom. Grind

just enough to give the magnum belted case rim a few thou-

sandths of an inch clearance. Use a factory-belted magnum

bolt for comparison and establishing correct dimensions.

If you have a bolt shroud that you cut with a carbide bolt

opening bit, this works fine. There’s a rotary burr (carbide)

available for in-tool post grinders’ use. Remember, super-

hard cutters can shatter easily. While the grinding stone

might take more time and touchy application, it has worked

best in my shop. After doing a few of these jobs, you’ll per-

haps join our crowd of “new magnum actions” lovers.

FIGURE 41—The three-jawchuck grips the rear of thebolt body. The firing pinhole was used to line withthe tailstock center. Thesteady rest was positionedand the toolpost grinderwas aligned to enlarge thebolt face.

Precision Sear Facing with Mini-toolPost Grinders

When you can afford it, purchase three to six small electric

hand grinders such as the Dremel Moto tools (Figure 42).

Having your most frequently used stones, cutters, or acces-

sories chucked and ready to use saves time (Figure 43). In a

busy shop, the need for them is endless. You can’t accurately

shape, cut angles, and grinder-turn hardened pins or parts

by hand.


FIGURE 42—Shown is aDremel Moto tool in the lathetool post grinder bracket,readying for sear surfacing.


Figure 44 shows an M-94 Winchester hammer being held in

a four-jaw chuck, with the Dremel tool post grinder almost

in place to commence a straight, microscopically undercut

grinding pass. The sear is worn slightly rounded, providing

too light a trigger pull that can be dangerous. The hammer

can be tilted upward in the chuck-hold to get sufficient

undercut (Figure 44).

FIGURE 43—Having extraDremel or other electricgrinders with the most-usedstones and cutters in placesaves much time.

FIGURE 44—A 0.023 inch ��15/16 inch emery cutoff wheelin a Dremel tool post grindercan make a perfect searrecut. The four-jaw chuck per-mits alignment adjustment.

The cutting stone is an emery cutoff wheel, 0.023 inch in

thickness and 15/16 inch new diameter. They’re brittle, easily

broken, and you must handle and feed them carefully, never

leaving them chucked up in your grinder. To remove the cut-

ting stone from the chuck without breaking it, loosen the

chuck easily, grip the mandrel with a small vise grip, narrow-

jawed pliers, or side-cutter, and pull from the chuck. Store

the mandrel with mounted cutoff wheel in a hole-base away

from contacts with other accessories or tools. There’s a lot of

life in just one of these discs if you care for it properly.

You can do a professional job of grinding screwdriver slots in

newly made screws with this setup. You can grind retaining

pin notches easily into newly made firing pins by using a

larger-width grinding stone. After familiarizing yourself with

some basic uses for the small tool post grinders, your inven-

tive mind will come up with dozens more. Handheld uses

for these grinders of metal, wood, and glass are endless.

Furthermore, having several grinders keeps you going in

case one breaks down.

Drill Rod for Making Parts

A tool steel drill rod for small parts making is available in

various lengths of round, square, and flats from Brownells.

Tempering instructions come with the rod. Lasalle “fatigue

proof” steel rods are also available in sizes inch, 1/4 inch,5/16 and 3/8 inch. The Lasalle rod has a higher ratio of man-

ganese to carbon, is very machinable, and tough without

being brittle. Also, it doesn’t require heat treating like low-

density mild steel. It’s ideal for firing pins, screws, spring

guides, and other parts subject to stress and repeated shock.

You can use parts made from Lasalle steel right away, thus

saving time (Figure 45).



W-1 Water-hardening Drill Rod

The W-1 drill rod is a fine-grained commercial-quality steel

containing 1 percent carbon, 0.4 percent manganese, and 0.2

percent silicone. You can use it for making dies, punches, and

other tools or parts that require a lot of hardness and a tough

inner core for top strength. It works well for pins for guns.

If an unusual depth of hardness is needed, you’ll need to

heat the parts from 1450 to 1600 degrees F. If a furnace isn’t

available, use 1450 Tempilaq. Keep at this temperature for

a few seconds, then quench in an 8 percent brine solution,

made from 3/4 pound rock salt in one gallon of water.

Tempilaq is available from Brownells in various temperature

degree ratings. Simply brush it onto the metal, and when it

reaches specified temperature, it melts. That’s the time to

quench.

To temper, give the part a one hour draw at the following

temperatures to result in the Rockwell hardness shown:

FIGURE 45—Shown are M-94Win. firing pins on the left andM-336 Marlin on the right, allbroken uniformly. Dry firingand excessive hardness isresponsible for such breakage.Having a drill rod supplyenables gunsmiths to makemany parts.

A round, 0–1 oil-hardening drill rod contains 0.95% carbon,

1.2 percent manganese, and 0.25 percent silicon. It’s available

in 1/4 inch round and larger. It’s characterized by superior

dimensional stability, machinability, and smooth finish. It

has a top rating for general shop use in dies, parts, tools, and

punches. Tempering and hardening are very similar. Heat to

1475 to 1525 degrees F. In lieu of a controlled furnace, again,

you may use Tempilaq. Hold at the 1500 Tempilaq tempera-

ture for a few seconds and then quench in light quenching

oil. Following this with a one hour draw gives the following

Rockwell hardness.

An unusual feature of these steels is that they have a low

draw temperature to achieve maximum torsion impact

strength. Drawing can be done in a kitchen oven, or you

can make a small furnace with furnace brick and a simple

controlled heat element.


FseergederutarepmeT ssendraHCllewkcoR

denedraHsA 76–66

002 76–66

003 56–46

004 26–16

005 95–85

006 55–45

007 15–05

008 74–64

FseergederutarepmeT ssendraHCllewkcoR

denedraHsA 56–36

003 46–36

004 26–16

005 06–85

006 65–45

007 35–15

008 84–64

009 54–34


Self-Check 6


1. You would need a _______ larger and more rigid than the Dremel Moto tool types foropening bolt faces.

2. To accommodate belted magnum cases, World War II military bolt-action rifle bolt faces required enlargement from _______ to _______ and grinding off the extractor lipaccordingly, while holding proper shape and tolerances.

3. _______ , available from Brownells in various temperature degree ratings, is a solutionwhen heat treating without an electric furnace.

4. The “NS” stamped on the front of Rock Island Arsenal receivers stands for _______.

5. Lasalle _______ steel rods are ideal for making firing pins, screws, spring guides, andother parts that are subject to stress and repeated shock.


SHAPING MUZZLES

Growing Barrel Muzzles(Sporters/Target)

There’s been a lot of propaganda on the value of various

shapes of muzzle crowns. Theoretically, some have said that

shapes tame or control the violence of muzzle blast gases

that might start bullets on a shaky route. As a lifetime com-

petitive shooter, World War II firearms’ instructions veteran,

and gunsmith since World War II, I’ve never been able to

prove such a theory.

From the accuracy standpoint, there seems to be no magic in

any form of muzzle finishing other than a cleanly trimmed

bore edge, with no burrs or metal rollover whatsoever. A

clean bore edge takes a supersharp piloted center drill or a

nonthroated reamer. Pushing and pulling a soft cotton patch

through that muzzle will indicate whether or not there’s any

microscopic bore-edge burring that picks up the tiniest fuzz

off the patch.

Only a 100 percent perfect, unobstructed bullet getaway at

that muzzle edge provides accuracy. Forceful polishing, grit-

loaded balls, or bevels almost always give a slight muzzle-bore

edge rollover that can be accuracy suicide. The old M-52

Winchester .22 L.R. target rifles had a flat muzzle finish

(carefully deburred). Its follow-up competitor, the Remington

M-37, had what I call a target-recessed crown. The crown is

a simple facing slight step-down cut from the bore partway

across the muzzle face to protect its edge from bump dam-

age. The barrel on the right in Figure 46 is a similar step-

down target crown.

The center muzzle in Figure 46 is the crescent-moon, rounded

sporter type, used on most factory and hunting weight arms.

The muzzle on the left shows a simple 60 degree piloted center

drill cut with a flat surface beyond and out to muzzle diame-

ter. This might not be as fancy, but it protects the bore edge.

This is your muzzle-finish priority.



You can always play with odd angles and shapes in your spare

time, which busy gunsmiths seldom have. While learning,

then working with gunsmithing, you’ll experience surprising

and amusing situations like the following.

One of our competitive, outstanding, four-position target

shooters (but somewhat rough in nature) displayed his newly

hack-sawed-off barrel shortening. The saw-off was jagged by

gunsmithing standards. “My gawd,” I snorted, “let me put

this in the lathe, face it off right and perfect the bore edge.”

“Shoots ta beat hell,” he assured me. “More likely shoots all

over hell,” I answered. He wouldn’t let me touch it! So smile

on your way back, with the checks from the other guys. And

never quit learning!

How to Crown (Face-off) ShotgunMuzzles

Shotgun barrel facing or crowning is as important as getting

perfect metalwork at the exit muzzle edge of rifle barrels.

Anything that interferes with uniform muzzle shot charge

escape is probably detrimental. Fortunately, it’s initially easy

to prevent. It’s a matter of follow-up when you correct the

nicks on a damaged muzzle caused by careless gun-handling.

What can also happen is muzzle cutback, made necessary by

muzzle mud or snow obstruction blowup.

FIGURE 46—On the right isthe typical target barrel step-down crown with bore- edgerelief. In the center is cres-cent-moon sporting crown withbore-edge relief. On the left isa deeper 60 percent centerrelief giving same protection.Take your pick!

Muzzle cutback usually calls for removal of 21/2 inches or at

least a portion of it (that comprises your shotgun barrel’s

choke). There are two solutions. First, you can install any of

the various choke, screw-in or screw-on adapter tubes, as

well as the adjustable collet types. Next, you can work a

choke back into it with the help of a B-Square swaging tool,

which includes complete instructions. It consists basically

of the gradual tightening of a heavy steel roller system, as

you rotate the unit from about 21/2 inches back toward the

muzzle.

The only accurate progress analysis is to unhook your tooling

system after each pass and take the gun out and shoot it

for patterning. Such a process is slow; so it’s possibly a

slack-time or wintertime project. Nonetheless, it can produce

surprising results.

For example, a single-shot, 16 gauge “junker” with a blown

muzzle rested in a dusty corner of my shop for years. One

snowy subzero day, I built a new firing pin, devised a hammer

spring, and tested the B-Square Choking tool. It worked.

After a few passes with those high-pressure steel rollers,

shooting tests proved I had a tight, full-choke pattern.

Next, I faced off the muzzle, clean and true. I could have

done it in the lathe with a lot of careful setup work. At that

time, Jack McIntyre of Troy, NC, provided me with a sample

of his shotgun barrel facing tool. It consisted of nylon pilots,

five inches long, in front of a disk-shaped file and brace-and-

bit type handle (Figure 47).

The long pilot brought the cylindrical file into perfect align-

ment with the bore. With the barrel locked in a padded vise,

the brace-and-bit handle enabled me to true up the muzzle

face in minutes, accurately and in less time than a lathe

setup would have taken. New gunsmiths should consider

this. All in this world isn’t yet totally mechanized, especially

gunsmithing. That handwork at the bench is still often what

separates the amateurs from the professionals.



The McIntyre tool comes with one nylon sleeve (pilot) of your

choice of gauges: 12, 16, and 20. It’s available in two sizes,

small for finishing single barrels, and large for single and

double barrels. This tool shortened facing jobs to 3 to 5 min-

utes. Time wise, I couldn’t even compare it to doing a lathe

setup.

However, there are possibilities of making a version of the

McIntyre tool to fit into lathe tail stocks. You budding young

gunsmiths have the world before you, as Jack McIntyre has

turned his inventiveness and skills elsewhere.

Remember that a mechanical flat facing tool still leaves a

sharp muzzle edge at the bore front. Rotating a beveled

Cratex rubber-grit impregnated or grit-treated felt polishing

bob inside the muzzle edge neutralizes this knife-sharp edge

in seconds. You can rotate the outside edge gently on a firm-

faced gritted sailcloth buffing wheel.

If the project involves a choke installation, the outside edge

will be against a choke adapter sleeve, out of sight, out of

reach. This makes deburring of no significance, and in fact it

could even contribute to a tighter seal.

FIGURE 47—The McIntyreShotgun Barrel Facing toolconsists of a sharp, rotary fileand interchangeable gaugenylon pilots, operated manual-ly via a brace-and-bit design. Itallows for lathe adaption.


Self-Check 7


_____1. Once you remove some muzzle length from a shotgun barrel, there’s no way torestore choke and the barrel should be trashed.

_____2. A supersharp piloted center drill or a nonthroated reamer ensures that a bore edgeis cleanly trimmed with no burrs or metal rollover whatsoever.

_____3. Forceful polishing can give the muzzle-bore edge rollover, which can affect accuracy.

_____4. A 95 percent unobstructed bullet getaway at the muzzle edge ensures optimumaccuracy.

_____5. The first muzzle-finish priority is to protect the bore edge.



ADVANCED GUNSMITHINGSKILLS

The Palmgren Milling Attachment for the Lathe

The Palmgren milling attachment bolts onto the lathe’s tool

post and is controlled by the compound and cross feed

(Figure 48). The arrangement often encourages a gunsmith to

purchase a genuine milling machine rather than substituting

for one. It is, however, handy for milling dovetail sight slots

into barrels and ramps, grooving out adjustable forestock

rails for target rifle attachments, and experimenting with

assorted nameless gadgetry (Figure 49).

FIGURE 48—The Palmgrenmilling attachment enabled us to cut this 1/8 inch and 1/4 inch slot for an adjustabletapering lathe gadget.

Years ago, Neil Kenney of Sandpoint, ID, made an adjustable

barrel taper turning attachment on and for my lathe with a

Morse No. 2 taper to fit the tail stock. It consists of a steel

bar with measurements of 11/2 inches � 21/2 inches � 51/2

inches, bored and silver-soldered onto the large end of the

Morse taper. A second identical steel bar 3 inches long was

slotted in from both sides inch wide for a distance of 1/4

inch. Next, a 3/8 inch mill was used to widen and deepen

these slots 1/4 inch or halfway through the bar.

The mill opened the bar slots for the 1/4 inch � 15/16 inch

20 TPI cap screws, which turn into the drilling and tapping

of the first bar affixed to the Morse taper. A 60 degree center

drill cut a center into the remaining solid section of the

grooved bar. The center drill was locked in the three-jaw

lathe chuck. With the forward adjustable steel bar of the

newly made unit centered and the Morse taper in the lathe

tail stock, the 60 degree center was cut using the center drill

in the head stock chuck.

The newly cut center area was then heated dull red with

Kasenit applied and melted several times and quenched at

a dull red for temper.


FIGURE 49—Cutting dovetailsight slots is only one taskyou can complete with thisgadget.


The setup provides a left and right adjustable tail stock center

without moving the actual lathe tail stock center. It can be a

fantastic time-saver. A well-lubed steel ball bearing was used

to fit into the barrel center and the center of the newly made

adjustable tail stock center, to be used for taper-turning bar-

rels. After making a portable leveling support from the ways

to the bottom of the taper unit, it worked amazingly well. The

adjustable bar was made using the milling attachment. This

is only one example of what you can do with such a tool

(Figure 50).

Lathe-making a Tap

If necessity is the mother of invention, desire is the father.

I had an extra-new M-69 Winchester .22 L.R. barrel on hand,

and a .22 rifle action that required a new barrel. With them,

my helper Bud and I discovered that the receiver on the rifle

with the damaged barrel was bulky enough to bore out and

thread for the new M-69 barrel.

Experimenting was in order that below-zero winter week. “We

might be able to make the tap on the lathe,” Bud commented.

Shortly, he returned from the machine shop with what he

FIGURE 50—Shown is a head-on view of the tail stock of thelathe-made taper attachment.The lubed ball bearing in thebarrel and the adjustable taperplate hold the barrel at tailstock.

presumed would be suitable bar stock. Bud was a mechanical

whiz on almost anything. He spent years as a millwright and

he had endless in-shop experiences. Initially, he trained me

to operate a lathe. There are many sources of learning. Take

advantage of every one you can.

After turning the steel to 5/8 inch diameter, he threaded it

24 TPI, even working a slight taper onto its end area. The

flute-cutting was slow and tedious without using the milling

machine. Bud ground a lathe bit into a “hook-rake” shape,

and hand-fed the longitudinal passes, advancing the cutter

very slightly for each pass.

The flutes weren’t really of adequate depth and width. This

was an experiment, whereby you always learn something and

do it better and different the next time. The face of the tap

teeth had to be faced with a small tool post grinder, using

one of those thin cutoff wheels and operating on a “touch

system.”

Next, we pursued tempering without an oven—again a gam-

ble. Bud used our shop system of heating dull red, melting

several coats of Kasenit onto the surface, then quenching at

dull red. It took several experimental runs before we got that

“ting and sing” response with a sharp file.

To test the homemade tap before risking a rifle action,

Bud bored a section of cutoff rifle barrel blank to 5/8 inch,

(Figure 51, threaded OK). This is merely an example of what

you can do with machinery and imagination. It has been said

many times that “gunsmiths are the world’s most inventive

people.” Such experiments add an intense interest to your

work.



The Milling Machine

Modern gunsmiths should also become aware of the short-

falls of a lathe milling attachment such as the Palmgren.

Those who require a complete milling machine come to realize

it and often consider “busting the budget” to get one. As with

a quality lathe, drill press, and endless small tools, a milling

machine’s uses are endless.

A member of our rifle team needed to standardize the

accessory rails of several target rifles to interchange with

a Feinwerkbaus Model 600, .177 caliber Olympic-type prac-

tice air rifle, his Model 2000 .22 L.R. target rifle, and a

Remington M-37 target rifle. The Feinwerkbaus has a unique,

ultraconvenient adjustable forend stop that unlocks with a

mere quarter counterclockwise turn. It locks tight in any

position with a clockwise quarter-turn anywhere along the

length of the accessory rail. The Feinwerkbaus is fast and

dependable.

Tim Hoechert, an aspiring young shooter and mechanically

inclined gun hobbyist, took measurements from the

Feinwerkbaus. He then picked up a bar of aluminum 3/4

inch wide, 1/4 inch thick, reground a milling bit to do the

FIGURE 51—Shown is the 5/8inch �� TPI threading tap onthe right, (M-69Winchesterbarrel shank specs), made onthe lathe. The arrow points tothe thread in the inch collarof the barrel steel made totest tap.


job, and provided me with a new accessory rail with two days

to spare. All this cost a fraction of the European cost minus

the long waiting period (Figure 52).

Cutting dovetails for sight installations are mere beginnings.

You can make obsolete sight bases, customize various mech-

anisms, and mill quarter-ribs on barrels. You can remove

excess metal from military

actions such as the bridge of 1917 Enfields, modify pistol

slides for custom sights, plus endless day-to-day needs as

they arise (Figure 53).

Rural and semirural gunsmiths will get calls for making repair

parts for various machines. Many jobs are easy compared to

complicated gunsmithing. Odd jobs will help you survive

through slack seasons until you establish your business.

You’ll need a bit of levity with some customers. For example,

a chap came in looking for a gun part he had broken (on an

obsolete model). When I asked for the broken parts so I

might copy them, he became indignant. “Yuh mean you don’t

remember what it looked like?”

Be patient, have fun! You can also experiment with muzzle

brakes and cutting slots in them. One of our gun-nut friends

has built several 50 caliber, bolt-action rifles. He won’t fire

them without his muzzle brake.

82

FIGURE 52—Shown is a coun-try shop equipped with lathe,milling machine, and weldingoutfits. Tim Hoechert’s gener-al mechanics ability keeps himbusy. Here, he demonstratesthe ease with which you canmill a 3/8 inch sight dovetail(to be followed with slightdovetail file cleanup fittingwork).


Welding Requirements

In average gunsmithing, welding different style knobs low

enough on bolt handles to clear scopes (including the large

eye-piece optics) is probably the largest material you’ll work

with. I personally detest the idea of cutting off military bolt

handles and welding on fancy-appearing substitutes. I just

can’t see applying all that severe heat so close to the bolt

body and cocking cam area.

Suppose a customer desires a spoon-shaped, knurled knob,

or any other decorative style. My theory is to forge the bolt

safely heat-wise to begin with, and then to cut it off about

one third or midway out from the bolt body. Then, weld on

the new knob in a manner that heat-protects the cocking

cam and prevents heat runs toward the critical locking lugs.

Caution: It’s imperative that you have some gas welding

experience before working on costly parts and/or parts that

you can’t replace. I advise a complete welding course.

If you can’t afford a complete course, most professional

welders can show you the ropes and give you a grand start

if you’re serious and pay attention. Attempt to actually work

with a professional in an apprenticeship for a while. You can

FIGURE 53—Shown left toright are collets: 3/8 inchdovetail, sight-slot cutter,large dovetail cutter, and fourmilling bits (a small portion ofmilling tools the machine canutilize).

learn the basics rapidly. Then, you can practice by yourself,

realize when you’re right or wrong, and make corrections

accordingly.

My instructor wouldn’t quit telling me over and over about

the ultra-importance of having that parent metal puddled

(melted) before adding melted welding rod metal. The parent

metal, usually being larger than the welding rod, takes more

heat and time to melt. Keep the welding rod in the bottom of

the parent metal puddle. Raise the rod and draw back the

flame if the puddle gets too big. These actions and reactions

must be fast, yet under control. Practice is the answer.

Caution: Usually, the beginning welder’s biggest error is

attempting to add melted welding rod to a heavier parent

metal that’s not yet in the melted stage. Beware of this!

Gunsmith welding is usually on small parts. You’ll need to

practice with a small welding tip, 1/16 inch rod, or taper-

ground smaller yet. When welding small, thin parent metals,

it’s a critical matter of mating flame, rod, and parent metal.

It requires fast application of rod at the flow stage and a fast

getaway to avoid damage to the delicate part.

Many small welding jobs are merely to correct worn parts’

buildup or to rejoin broken parts. You must remove excess

weld metal if it interferes with functioning. However, if no

interference exists, merely partially smooth your weld. Extra

dimension adds strength.

Tempering and/or Case-hardening

You can often improve buildups on gun parts’ wear surfaces

by tempering and/or case-hardening. Heat the part dull red,

dip it into Kasenit hardening powder, apply a torch to melt

in the chemical, dip into powder, and melt two more times.

Then, when it reaches dull cherry red, dip it into cool water.

This usually gives a long-wearing ultrahard surface, yet the

inner metal isn’t breakage-hard.

Years ago, my shop did many M-94 Winchester Link nose

buildups on part number 4694X Link. The front end of this,

which I call the link nose, controls the retention and entry of

the next round of ammunition into the action above the car-

rier. The carrier angles upward at lever opening completion



and lines the round up for chamber entry upon lever closure.

These link noses were soft steel, wore easily in fairly new

rifles, and sometimes permitted a cartridge to pop back

under the carrier and hopelessly inactivate the rifle. This

made the rifle useless even as a single shot!

My years-ago grizzly bear guide in Canada admitted he

bloody-well had to dig “euwt” shells with a nail now and then

(not to my liking as a guide’s backup rifle). I managed to get

his .30–30 M-94 Winchester into my shop and correct this

along with adding a new barrel and other necessary parts.

Dozens of these link nose buildups and hardening jobs hap-

pened during the heyday of my in-town shop. I became so

familiar with it that I no longer needed to measure the link

nose, only glance at it after the weld-up and grind-down, then

Kasenit it. Not one of these repairs ever came back. The new

hardness stopped all wear. Too bad the factory couldn’t have

done this originally, but it leaves endless work for upcoming

gunsmiths, if you pursue it. This is just one worthwhile

example of what welding buildup and Kasenit hardening

can do.

Hardening surfacing with a welding rod is also a possibility.

A welding supply business can provide you with all pertinent

information. Most gun parts are too small for this applica-

tion, but keep it in mind. If you’re going to become a welder,

you’ll be repairing many parts besides guns. Gun shops often

accept assorted repair work. It’s beans in the pot and another

payment on the lathe and equipment.

Note: You may require separate instruction/learning on elec-

tric (arc) welding. It’s usually less applicable to gunsmithing

than the acetylene oxygen welding setup, but pass up

no learning opportunity. You’ll discover places to use it

beneficially.

Welding Instruction Books

The number of publications available for learning about

welding is surprising. As a gunsmith, forget the heavy-duty

bulldozer and horse-drawn grain binder bull-wheel repair

instructions. Stick to the delicate and fine points of the gun-

smithing trade. However, read and study all the books you

can. Opinions and methods differ, but gunsmithing school

intelligence will guide you as your experience broadens.

Soft-soldering vs Silver Soldering

Some claim silver solder to be as strong as anything it will

bond with. Steel must be heated nearly red and fluxed in

order for it to flow and take. Surfaces must be clean. Silver

soldering is used often on parts joining and repairs not relat-

ed to the rifle’s action or barrel, as the extreme heat required

can change tempers and become detrimental, even dangerous.

Installing front sight ramps with silver solder is a “no-no” in

our shop!

Brownell’s Force 44 soft solder is easy to use with Blitz sol-

dering flux. When the adjoining barrel area is covered with

talc crayon, the solder won’t run. Any slight edge-over can be

sanded off before bluing, and the solder survives the blueing

in-tanks treatment. It’s strong, and we’ve had no failures. Its

low-temperature melting is extremely desirable, which makes

it easy to use by novices as well as professionals.

Front Sight Installation

It’s just as easy to install front sights correctly as it is to

“goof ‘em.” I’ve seen many front sight ramp installations done

with induction brazing or silver solder. It takes severe heat to

remove them. Likewise, original installation called for similar

temperatures, which can be detrimental to barrel and action

steels, temper retention.

Ordinary soft solders of the past failed to hold up under

“tank-bluing” chemicals such as Oxynate #7, BLU-BLAK,

and others. They didn’t hold up unless a dangerous cyanide

additive was used as well as low temperature control, which

required much ventilation. Silver-bearing Force 44 soft solder

melts, flows, and adheres easily to clean steel surfaces. Place

the barrel in a padded vise, align it vertically as close as pos-

sible with the action, and place the ramp on the top front of

the barrel in the desired location. Do your best to get it accu-

rately on top. Then, use a sharp, metal scribe to mark out its

outline, and remove and gently sand off any bluing ruse or



discoloration from the ramp affixing area. Next, with a Talc

crayon, coat the barrel area surrounding the proposed ramp

position. Use a heated soldering iron or unit to melt Force 44

soft solder onto this fenced-off part of the barrel front.

Note: At the same time, you should have the steel ramp fixed

in a vise bottom-up with a cleaned surface. Apply Blitz solder-

ing flux and Force 44 as you’re doing to the installation sight.

Don’t forget the flux, and don’t overdo the application. It only

takes a good surface coating, not any form of pileup solder.

How do you get the ramp exactly on top? Considering the

position of the barreled action in the stock, the manner in

which a shooter might hold it (yet still claim level) makes it

difficult. However, the mechanical level must prevail. There

are level-seeking devices such as B-Square’s Cross-Hair

Square that work from the flats of the bolt-way’s lugs milling.

Nothing I know of could be more accurate.

However, a ramp front sight’s response isn’t as easy. The

shooting eyes must also play a part. After the barrel surface

and the underside of the ramp are tinned (light coating of

solder on the surfaces), position the ramp on the barrel as

level as possible. Then, place a balanced weight hanger over

the ramp, and apply moderate heat with your propane or

acetylene torch, only enough to melt the solder (Figure 54).

You’ll see the ramp settle snugly onto the barrel. Unless you’ve

overdone the tinning solder applications, only the tiniest

amount will ooze out from under the ramp. Pull the heat

temporarily and make a fast visual inspection for vertical

and horizontal alignment. While the solder is still fluid, you

can gently tap the ramp left or right.

You must make a final check after the solder sets up. Place

the barrel and action into its stock and assume different

shooting positions.

Doing so will help you determine whether you have a 12 to 6

o’clock lineup. If not, reheat the barrel and ramp area and

gently tap the ramp as needed to line it up.

The ramp installation system also works well with open, rear-

sight “higher station ramps.” Furthermore, European-type,

to-barrel formfitted front sling swivel pads can be soldered

in this system without concern about failures.

The shop-devised three pound weight hanger ramp holder

works fine; however, you might prefer an Erhardt spring-

loaded sight soldering jig or other clamp-type fixtures.

Parts-holding at the Workbenches

Vises at every workbench are often not enough (Figure 55).

Additional gadgetry such as the large “Octopus” with four

adjustable ball joints, and the “Mini-Octa Holding Tool” save

a lot of time and enable you to do better work on odd-shaped

parts.


FIGURE 54—This no-cost, 3 pound balance weightdevised in the shop brings the ramp snugly to the barrelwhen solder-tinned surfacesmelt. Adjustment for left-rightvertical lineup is easy whilehot.


Thinking gunsmiths can also come up with endless ways to

hold gun parts (Figure 56). On my list are wooden clothes-

pins, rubber bands, masking and electricians’ tape, three-

minute epoxy, and rubberized glue. All of these are easy to

remove after their usefulness is over.

I’ve used the compound vise on the Delta drill press, as it

swings, lowers, and elevates. You can line it up with any

round part being held in the drill press chuck by using a “V”

block to align it. This can be worked out quite similar to the

head stock and tail stocks in the lathe (although the lathe

setup is faster and better).

FIGURE 55—Shown are fourside-swinging adjustable balljoints, and two grafted-on visegrips. This 14 inch high,Octopus holding tool is adandy for welding and soft orsilver soldering.

Many gunsmiths find that photography advertises and sells

their wares. Clutter in the foreground, background, and

elsewhere is difficult to eliminate in a busy shop full of

equipment.

Our swinging drill press table with compound vise saved the

day for many of the photos shown in this unit. I locked up

a 21/2 foot length of 11/2 inch square wood to 11/2 by 11/2.

Doing so, I was able to bring the position of the items out to

the side where we could provide white, gray, or black back-

drops, as well as making proper lighting possible. For some

work, we used thinner pieces of wood material.

We used the methods just mentioned to hold items in place.

At one point, three vise grips were hooked onto each other,

plus clothespins and metal clipboard clamps (which will often

work to hold small parts for soldering or welding). After some

time, toying with ways to hold parts creates ideas your mind.

With some thought, you’ll be able to devise ways of holding

almost anything where and how you want it.


FIGURE 56—The Mini-Octa-Holding tool weighs one poundwith base, has less adjust-ment, but can hold in positionbroken small parts for weld-starting or silver-solder repair.It’s shown here gripping an M-94 Winchester carrier.


Joining Two Firing Pins

Admittedly, there’s no substitute for correcting a broken fir-

ing pin by installing the proper new one. However, at times

(like in distant locations) a new part may not be available.

Fortunately, firing pins, often a fairly breakable part, can

likewise be made by gunsmiths with a lathe and basic equip-

ment. The work may require additional charges, but you

can keep your customer satisfied. Figure 57 shows a broken

M-94 Winchester firing pin with its rear end in the head

stock lathe chuck. The front broken point end has been

removed with a bench grinder cutoff wheel, as has been the

front section of a second broken M-94 Winchester firing pin,

being held in smaller tailstock chuck. Both ends have been

“V” ground for welding together easily and completely.

When actually welding, shield your chucks and lathe ways. I

only partially weld such lineups in the lathe to prevent the

possibility of heat damage to costly equipment. You can

remove the unit and finish the welding while it’s being held

in a regular workbench vise. After this, partly grind off the

welded surface and then return it to the lathe to obtain a

perfect final diameter. The cutoff wheel will remove the extra

length of the long end, and you can commence the tedious

task of copying the original dimensions.

FIGURE 57—Welding or silversoldering two round pins,parts, or screws together in perfect alignment is bestdone between lathe headstock and tail stock. Shieldchucks and ways during actualwelding. Only start your weldin the lathe. We omitted theshielding for the chucks forphotography reasons.

Someone will ask, “Why copy a firing pin if you have one to

copy from?” We don’t have one to copy. M-94 firing pins

almost always break at the tip beyond the major curve-down

from body diameter. You can always check tip size against

the firing pin opening in the bolt face. Since in this instance

we welded together two M-94 firing pins, you would be dealing

with metal too hard to turn in the lathe properly. You could

anneal it or use a tool post grinder to shape it.

Better yet, if and when you make this type of weld-on exten-

sion to form a M-94 firing pinpoint, use a drill rod. It’s usually

tough enough to do well without tempering tinkering.



Self-Check 8


1. You can improve the wear surfaces of gun parts by _______ and/or _______.

2. The Palmgren milling attachment bolts onto the tool post to be controlled by the _______and _______ .

3. Before you weld expensive parts or those hard to replace, you should get some _______.

4. Welding on different style _______ low enough to clear scopes is probably the most oftenpracticed welding task in average gunsmithing.

5. The Palmgren milling attachment is handy for milling _______ into barrels and ramps.


BUILDING YOUR OWN EQUIPMENT

Gunsmiths of yore made many of their own tools. However, it

takes some equipment and tools to make more tools. It also

takes a lot of time and energy that you can afford to expend

only if the end result is compensatory to the other side of the

ledger. All the gunsmithing skill in the world doesn’t help if

you have improper tools, no tools, and/or you’re unable to

procure or make them. Experiencing the art of making some

of your own tools and equipment is in itself practical gun-

smithing experience. Don’t let any ingenious ideas die on

the vine.

When everyone in the shop is busy, it’s impractical to take

time out to experiment and devise new tools. Besides, most

needs are available from gunsmiths’ supply houses such as

Brownells and B-Square. However, you’ll have slack time.

In fact, vigorous young (and old) gunsmiths with intense

interest and enthusiasm make spare time to bring ideas

into creation.

Building a Glass Bead Blasting Cabinet

Glass bead blasting cabinets are available in many sizes and

forms at various prices. With welding expertise (every gun-

smith should take a good course in welding), you can study

the various patterns and build your own cabinet. This will

save you money and add to your welding experience. My pre-

liminary welding instruction came from a bulldozer and logger-

truck mechanic. However, he took great pride in doing the

tender things also, frequently demonstrating running a bead

across a Prince Albert tobacco can using a 1/8 inch diameter

welding rod. You’ll need to acquire the technique of handling

tender welding jobs. It takes practice and intense interest

and desire. Gunsmithing also requires acetylene equipment.

Building your blasting cabinet is an ordinary welding job,

one that you’ll probably best handle with an electric welder.

Formulate a plan covering dimensions, so you can cut each

steel plate cut accordingly. You cut the two-arm working



holes into the cabinet with an acetylene cutting torch, as well

as the working view window on the top hinged cover 24 inches

� 45 inches. The view window in Figure 58 measures 8 inches

� 1/2 inch and is too small. It should be enlarged by about

25 percent. The top of the swinging door is full-width-hinged,

the underside lined with a “refrigerator door” type sealing

cushioning material to contain all dust.

The gadgetry on the right side of the cabinet is a canister-

type moisture collector (a must), inside light fixture, and

switch. Without the moisture collector, your metal will be

moisture-scarred.

The measurements of the cabinet are as follows.

• The depth of the front flat face of the cabinet where the

working arm holes are is 71/2 inches.

• From there to the bottom of cabinet “V” is 10 inches.

• From the “V” to the upward angle is 20 inches.

• Then it’s 12 inches vertically to meet the back side

hinged top door.

FIGURE 58—Shown is a blastingcabinet with a full-size top door24 inches �� 45 inches, which is adequate for most barreledactions, including shotguns. Theview window should be larger.Most 36 inch wide blasting cab-inets, commercially available,could be inconveniently small.Study your purchases.

The left side of the cabinet has identical dimensions but

without accessory cut-ins. A large, centrally located handle

is affixed to the lower edge of the swinging opening door.

At the bottom of the “V” cabinet, you’ll need about a 421/2

inch exit pipe, trimmed flush and smooth inside the cabinet.

The pipe makes brushing out all the old worn-out glass

beads from time to time an easy task. Have a bucket placed

on a shelf under the drain spout to catch all the worn beads.

The front legs of this cabinet are 38 inches high; the rear legs

inches high. Steel crossbars measuring 1 inch by 20 inches

are a square, channel-hollow steel material. They were weld-

ed onto the front and rear legs at 10 inches from the bottom

on both the right and left sides of the frame. To add rigidity

to the leg frame, a similar bar was welded onto the rear left

and right legs, 43 inches span. To stiffen the frame even

more, another 1 inch bar was welded into place from the

lower left, 10 inches above the bottom brace cross section

and upward at an angle to join onto the top of the right rear

leg. This steel frame provides room for shelf boards to hold

extra glass beads, gloves, and the bucket under the drain

spout. You’ll need to make an almost airtight plug to seal

the inside of your drain spout. I made mine with wood and

a cloth cover thumped into place with a hammer.

Warning: Don’t forget to cut about a 6 inch hole into the

back side of the blasting cabinet and install and completely

seal a plastic pipe to the outdoors or dust receiving area.

During the initial excitement of our success, neither my

helper nor I remembered the need for an exhaust pipe. The

initial tryout created a mushroom cloud of glass bead dust

forced out by the blast gun along the door edges into the

shop.

Another important addition is to affix a frame over the inside

of the cabinet door view window. Cover this with clear plastic

that can be replaced easier than installing new window glass.

Battering from the glass beads under pressure soon dulls

both window glass and plastic.

To prevent wear on the steel body material, the inside of this

cabinet was completely covered with a heavy doormat of

rubberized smooth material. The arm holes consist of long

gauntlet rubber gloves with sealed rear edges and strips of



foam cushion-type material about inch thick and inch wide,

sealed with rubber cement. The sloped back of the cabinet

provides easy reach. The width accommodates long barreled

actions, such as M-97 shotguns, long-barreled rifles, and

other surprises. The slight extra size of the cabinet doesn’t

cost extra.

A wooden “L” frame holds the position and keeps barrels,

actions, and barreled actions off the cabinet bottom and in

position to glass bead blast. The frame is 11/2 � 11/2 � 20

inches in length and two 7 inch pieces of the same material,

strapped together by two thin wood slats. There are three

wooden pegs installed in each long section of the “L” frame.

This provides spacing for better bead blasting. Use a soft

wood such as cedar for the suspension frame. This also

minimizes finish marring.

There are numerous plans, designs, shapes, and sizes of

blasting cabinets, many available commercially. Regardless,

it makes good sense to build your own. Then you can provide

yourself with the features most desirable to you. You should

consider some of the aforementioned points of size, view

window size, and protection from blasting erosion with the

clear plastic. Don’t forget the moisture-collecting gadget.

When purchasing glass beads, there’s little reason to buy

the fine size. The beads wear “fine” quite rapidly.

Warning: When using the blaster, wear a good respirator

and observe the warnings on the canister container bucket.

Also, always wear eye protection. Avoid dusts and vapors

from all types of products. In my shop, we cover the front of

our respirators with a heavy, fuzzy flannel cloth, held over

the screw-on filter cap with a tight rubber band. This precau-

tion is simple, yet effective. It’s surprising how much “crud”

you’ll rinse out of this cloth, and you’ll also add to the filter

life—as well as your own. Metals, grinders, buffers, hand

electric tools, even sanding a gun stock, all create dusts.

You should protect yourself from it.

Plans for a Belt Sander

Jack McIntyre holds a diploma from International

Correspondence Schools. His own shop-made small belt

sander wasn’t super-costly in the beginning (Figure 59).

Any go-getter can build a similar one, as well as the barrel-

holding cradle, with turning centers.

Among his other gadgets is a “V” flat spring swaging pliers

alteration that saves time and places the “V” where you want

it. It also works on round spring stock.

Note: Following are the actual plans for building the belt

sander pictured in Figure 59. Jack McIntyre provided the

plans with his compliments. After 15 years of use, the sander

is still performing better than most store-bought models.

Read the instructions all the way through and study the

drawings that follow them before you start. Make the parts

one at a time, and carefully follow the instructions.

Fitting the bearings is the only critical measurement in the

entire sander. You’ll notice the word “approximately” used

a lot. Substitutions such as the size of pipe and most other

parts are OK.


FIGURE 59—Gunsmith JackMcIntyre built this simple, yet efficient belt sander andbetween-centers barrel-holdingcradle. You can build a similarone.


Making the Sander

The suggested parts list is as follows.

• 34 inches of 1 inch black steel pipe

• 1 each 4.000 diameter � 1.000 floor flange

• 1 each 11/2 inches double-strength pipe, 4 inches long—

or 2 inches round cold rolled steel rod

• 12 inches of 3/4 inch square steel, cold rolled

• 11/4 inches 11/4 inches � 3 inches cold rolled steel

• 3 inches � 3 inches � 1 inch cold rolled steel

• 2 each 203 sealed bearings

• 2 each 202 sealed bearings

• 1 Volkswagen valve spring (or whatever else you have, or

can get) for a belt tension spring

• 2 inch pulley

Note: We didn’t list miscellaneous screws. You’ll see them in

the drawings.

Figure 60 illustrates the first stage of the belt sander. Take

11/2 inch, double-strength, 4 inch long pipe and bore out

both ends to 1.5730 diameter 500 deep. This is for the 203

bearings to fit in (part A in Figure 60). You can use a piece of

2 inch round cold rolled steel for this part. After boring it

out, place it aside and go to next step.


FIGURE 60—The First Steps ofthe Sander


Make Shaft A from an 8 inch piece of 3/4 inch cold rolled

steel. Figure 61 shows the detail of Shaft A in the upper

right-hand corner. Place Part A aside and continue to the

next step.

You can make Wheel #1, also in Figure 61, from wood, lami-

nate, or any other substance you want. I used a wheel out of

a textile mill 6 inches � 2 inches. It was, at one time, on a

hand truck of some sort. It should have a rubber covering. A

2 1/2 inch length of inner tube makes a fine cover. Nu-Matic

Grinders, Inc., Cleveland, OH, sells an inflatable grinding

wheel, which also would be excellent here. However, it does

cost $75, and the price may have risen since I last checked.

Put aside these parts and don’t try to assemble anything yet.

Cut 30 inches of 1 inch pipe to make Pipe C (Figure 60).

Thread and screw it tightly into the floor flange.

Cut 33/4 inches of 1 inch pipe for Pipe B.

FIGURE 61—The Second Steps of the Sander

Grind one end to fit the contour of Pipe C. Grind the other

end to fit the 11/2 inch Pipe A.

Weld Pipe B square to the center of Pipe A. Position the other

end approximately 6–7 inches from flange end of Pipe C and

weld it, making sure it’s all square before you weld.

Assembly A. Make Wheel #2 21/2 inches � 2 inches thick

as indicated in (Figure 62). You can make Wheel #2, like

Wheel #1, out of practically anything as long as it has a rub-

ber cover and a crown. In case you’re uncertain about what

I mean by a crown, it has a larger diameter in the center than

on the outside edges. Approximately 1/8 inch will be fine; it

doesn’t have to be exact. See Figure 62 for the miscellaneous

parts and instructions for this wheel assembly.


FIGURE 62—A Full Drawing of the Sander


Part B. For the shaft, take a piece of cold rolled steel, 3/4 �3/4 � 6 long, and turn one end down round as shown in the

drawings. Thread as shown, but don’t bore the hole at this

time. Put this aside for now.

Parts C and D. Take one 3 inch � 3 inch, 1 inch cold rolled

steel to make parts C and D. Drill a 15/16 inch hole 1 inch

from one side, which will eventually be Part D after you split

it. Next, drill two holes, 1/4 � 2 inches deep, then ream these

two holes out to 0.344 � only 1 inch deep, as shown in

Figure 62. Saw the part in two pieces at the center of the

1 5/16 inch hole. Now it looks more like the drawings. Cut

the notch in Part C according to measurements shown in

Figure 62. Drill holes through on the sides 0.375 inch diame-

ter as shown, tap holes as shown, and place them aside.

Part E. Cut 1.375 length of 3/4 inch round and drill a inch

hole through the center.

Part F. Cut 3 inches of 3/4 inch � 3/4 inch square steel.

Contour one end to fit Part E, as shown.

Part G. Cut a 3 inch length of 11/8 inch (or 11/4 inch)

square steel. Mill it out as shown in Figure 62. You can also

fabricate this part out of 3/16 inch or 1/4 inch plate steel,

whichever is easiest and cheapest for you.

Now, weld Parts E, F, and G together, as shown in Figure 62.

Then, drill and tap holes in G, also as shown in the drawings.

Part H. Cut two pieces of steel 1/4 inch � 3/4 inch � 21/2

inch. Weld one on the bottom of Part F and one on the bot-

tom of Part C. Drill and tap Part H 1/4 inch–20 (Figure 62).

These screws are only to keep the spring from falling off. This

was the way I did it. (You may think of a better way.)

Assembly of Parts

Examine Figure 63 carefully before you start, especially the

assembly of Shaft A (Figure 61), Pipe A (Figure 60), and the

bearings. Study the drawings carefully, and get all the neces-

sary parts for this assembly. Put Shaft A through Pipe A, put

a bearing on each end, and press the bearings inside the

pipe and onto the shaft.

Note: Both bearings are pressed inside at the same time.

Install Wheel #1. Install the pulley as in Figure 61.

Install Parts C and D. As shown in Figure 63, install parts

C and D around the pipe, but down close to Wheel A. This

assembly is here temporarily—until the positioning of the

wheels is complete. Then, you’ll move it up to the correct

position.

Install E, F, and G Assembly. This attaches to Part C with

a 3/8″ � 3 inch steel dowel, as shown in Figure 63.


FIGURE 63—Assembly Drawingof the Belt Sander


Installation of Wheel #2 on Part B. Figure 62 shows the

assembly procedures.

Next, put Part B (refer to Figures 62 and 63) into the milled

slot in Part G with a temporary space fitted into the top of

Part G. This will fill up the slot so that when you drill the

hole in Part B, it will be in the correct position. The hole is

already drilled in Part G. After drilling the hole in Part B,

remove the temporary spacer. Part B will then have the nec-

essary pivot up and down for tracking the belt. The tracking

screw goes in the top, as shown in the assembly drawing.

Now, install the Belt Tension Spring. After doing so, you can

raise Wheel #2 to its correct position, which is determined by

the length of your sanding belt. You can use up to a 54 inch

belt with this length pipe. To use a longer belt, you need a

longer pipe. I use a 2 inch � 48 inch belt.

Use a motor approximately 1/2 or 1/3 horsepower, 1725 rpm,

with approximately a 3 inch pulley. You can mount this

motor on the sander at the most convenient place for you,

either underneath or behind. Sometime you can find this

type of motor at most flea markets for a low price. They’re on

washing machines, dryers, etc. Or, you can buy a new one.


Self-Check 9


_____ 1. Experiencing the art of making some of your own tools and equipment is in itselfpractical gunsmithing experience.

_____ 2. If a glass bead blasting cabinet doesn’t contain a moisture collector, the metal thatis glass blasted will be moisture-scarred.

_____ 3. It’s not necessary to exhaust vent a glass bead blasting cabinet, as the cabinetitself is sealed and no dust can escape.

_____ 4. In the belt sander plans, fitting the bearings is the only critical measurement in theentire plan.

_____ 5. You should make the walls of a good glass bead blasting cabinet out of oak.


107

Self-Check 1

1. False. They break easily.

2. True

3. False. You can start a thread with a new taper tap.

4. True

5. True

Self-Check 2

1. flare

2. shim pack

3. wire brush

4. bore-sighting

5. left, right

Self-Check 3

1. False. You should retract the torch flame gradually.

2. True

3. False. Altering bolts takes experience and practice to

master.

4. True

5. True

Self-Check 4

1. Emery stones

2. felt-gritted bob

3. extractor claws

4. insufficient tension

5. loaded cartridge

An

sw

er

sA

ns

we

rs

Self-Check Answers108

Self-Check 5

1. True

2. False. It can be about 0.003 inch larger.

3. True

4. False. The chrome-moly demonstrates a gilt-edge

accuracy loss quicker than the stainless steel.

5. True

Self-Check 6

1. tool post grinder

2. 0.063 inch, 0.065 inch

3. Tempilaq

4. nickel steel

5. fatigue-proof

Self-Check 7

1 False. You can restore the muzzle by installing adapter

tubes or by using a B-Square swaging tool to work a

choke into it.

2. True

3. True

4. False. Only 100 percent provides accuracy.

5. True

Self-Check 8

1. tempering, case hardening

2. compound, cross feed

3. gas welding experience

4. knob bolt handles

5. dovetail sight slots

Self-Check Answers 109

Self-Check 9

1. True

2. True

3. False. Install an exhaust pipe from the cabinet to the

outdoors or dust receiving area.

4. True

5. False. The walls of the blasting cabinet are made of

steel.

Self-Check Answers110

NOTES

111

925 Oak Street

Scranton, Pennsylvania 18515-0001

Basic Metalwork and Machine Tool Operation

When you feel confident that you have mastered the material in this study unit, complete the following examination. Then submitonly your answers to the school for grading, using one of the exam-ination answer options described in your “Test Materials” envelope.Send your answers for this examination as soon as you complete it.Do not wait until another examination is ready.

Questions 1–20: Select the one best answer to each question.

1. You can use a lathe for all of the following applications except

A. threading barrels.B. making firing pins.C. mounting recoil pads.D. opening bolt faces for larger cartridges.

2. What type of wheels would you use to achieve a much smootherfinish with an effective contouring capability after an approximategrind-down of a welded repair?

A. Felt 50, 120 grit C. Felt 340, 450 gritB. Felt 150, 240 grit D. Felt 500, 600 grit

3. The best barrel sleeves are made of

A. hardwood. C. steel.B. bullet lead and bearing babbit. D. lead.

EXAMINATION NUMBER:

Whichever method you use in submitting your examanswers to the school, you must use the number above.

For the quickest test results, go to http://www.takeexamsonline.com

Ex

am

ina

tion

Ex

am

ina

tion

02530600

Examination112

4. When soft-soldering a front sight ramp, cover the adjoining area with _______ so the solder won’t run.

A. talc crayon C. TempilaqB. barrel grease D. flux

5. When forging/shaping a bolt, it’s best to use

A. an 8 ounce ball peen hammer. C. a 12 ounce carpenter’s hammer.B. a 10 ounce brass hammer. D. a 1 pound wooden mallet.

6. Prior to drilling and tapping military barrel actions, it’s always preferable to

A. heat the entire receiver ring area.B. coat the receiver with abrasive compound.C. remove the barrel from the action.D. anneal the barrel area.

7. The muzzle type most often used on factory and hunting weight arms is the

A. step-down crown. C. 60 degree center relief.B. crescent moon. D. 72 degree center stylus.

8. When jeweling, the drill press is run at

A. low speedB. medium speed.C. high speed.D. different speeds during different parts of the process.

9. The beginning welder’s biggest error is usually

A. selecting the wrong size welding tip for the job.B. leaving excess metal on the weld.C. adding melted welding rod to a heavier parent metal that’s not yet in the melted stage.D. selecting the wrong type of welding rod.

10. A small, effective center punch used to start drill holes for the most popular scope basescan be made from a broken super-hard

A. 10 drill. C. 25 drill.B. 17 drill. D. 31 drill.

11. Whether using a parallel clamp, calipers, or an elaborate drilling jig, for accurate hole location and drilling you should do all of the following except

A. concave spot grind. C. rescribe several times.B. scribe. D. center punch the steel.

Examination 113

12. Due to slight internal muzzle damage possibilities during manufacturers’ turning of barrelblanks, you should cut about _______ from the muzzle prior to chambering.

A. 1/4 inch C. 11/2 inchesB. 1/2 inch D. 4 inches

13. Fine-cut chisels respond to a delicate application of buffing wheels with grits of _______and down to rouge, provided you learn how to hold them for proper angle and tension.

A. 150–200 C. 350–400B. 250–300 D. 450–500

14. Surfaces heat treated with Tempilaq should be quenched in a(n) _______ percent brinesolution.

A. 2 C. 8B. 4 D. 16

15. Most scope-mounting mistakes of would-be gunsmiths are caused by

A. ignoring the instructions. C. inferior scope mounts.B. lack of quality tools. D. excessive metal finishing.

16. Military conversions most often suffer from

A. inadequate barrel length. C. cartridge feeding problems.B. faulty safety mechanisms. D. too much trigger pull.

17. Fine jeweling is dependent upon all of the following except which one?

A. The base polish C. Fixture indexingB. Your manipulation of the drill press D. The type of wire brush you use

18. It’s best to mount a barrel vise

A. to a lathe. C. to a wooden bench.B. to a shop’s side wall. D. on a concrete pillar

19. Parts that must be heat-treated to unusual depths of hardness must be heated from

A. 650 to 800° F. C. 1,250 to 1,400° F.B. 950 to 1,100° F. D. 1,450 to 1,600° F.

20. When scope body metals are forcibly held in a bind, this condition is referred to as

A. scope strain. C. scope warp.B. pressure pointing. D. scope inertia.

study unit basic metalworking and machine tool operation

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