Seatember- Uctober 1980 I.

R i f l e e l , “Only accurate r i f les are interesting*

Volume 12, Number 5 September-October 1980

The Magazine for Shooters (ISSN 0162-3583)

IN ,THIS ISSUE DEPARTMENTS

Favorite Guns Past and Present ....................... Bob Hagel

Hall B and Shilen BP Actions. ..................... Stuart Otteson

7mm Express & Magnum - A Comparison. ........ Mike Venturino

Target Rear Sights .................................. L.F. Moore

New Version of an Old Favorite. ....................... Gil Sengel

A Test of Rust Inhibitors. ......................... Layne Simpson

Inside the Spring-Piston Air Rifle ....................... J.I. Galan

Simplified Ballistics ............................. Arthur J. Pejsa

18

22

26

29

32

36

38

40

Spotting Scope ................ . 6

Dear Editor ................... . 8

Book Reviews. ............. 10,64

Rifle Patents .................. 1 2

Aiming for Answers .......... . 14

NBRSANews ............... .34a

Classic Rifles ................ .35 Trophy Pointers ............... .66

ON THE COVER

If anyone doubts that the United States is the country where the finest custom rifles are made, let him look at a Dair twical of the best we have to offer - such as this pair from the David Miller Company. The Mauser is a square-bridge .500 Jeffery, the left-hand Remington 700 a

Adopted in August 1969 as Official Publication rebarreled 7mm Remington Magnum. Photograph by Rick Croy For National Bench Rest Shooters Association

Rille Magazine. copyright 1980, is published bimonthly by Wolfe Publishing Co.. Inc.. (Dave Wolfe. President). P.O. Box 3030. Prescott. Arizona 86302. Telephone (602) 445-7810. Second Class Postage paid at Prescott. Arizona and additional mailing offices. Single copy price of current issues . $2.00 Subscription price: six issues . $10.00; 12 issues - $18.00: 18 issues . $26.00. (Outside U.S possessions and Canada . $13.00. $24.00 and $35.00) Recommended foreign single copy price . $2 50 Advertising rates furnished on request. All rights reserved.

Publisher of Rifle is not responsible for mishaps of any nature which might occur from use of published data. or from recommendations by any member of The Staff No part of this publication may be reproduced without written permission from the editor. Manuscripts from free-lance writers must be accompanied by stamped self.addressed envelope and the publisher cannot accept responsibility for lost or mutilated manuscripts

Change of address. please give six weeks’ notice. Send both old and new address, plus mailing label i f possible. to Circulation Dept , Rifle Magazine. P O Box 3030. Prescott. Arizona 86302

4

The Staff Dave Wolfe, Publisher Ken Howell, Editor Jana Kosco, Advertising Manager Wyatt Keith, Assistant Editor Dave LeGate, Art Director Mark Harris, Staff Artist Barbara Pickering, Production Supervisor Lynda Ritter, Editorial Assistant Joyce Bueter, Circulation Director Terry Bueter, Circulation Manager Susan Hancock, Circulation Assistant Wanda Hall, Accounting R.T. Wolfe, Ph.D., Consultant

Technical Editors

John Bivins Bob Brackney Bob Hagel A1 Miller Stuart Otteson Homer Powley Layne Simpson Ken Waters

RIFLE 71

When you only get

one chance only get

one chance

6

Those Overlooked Lower Powers “Oh, no - four power is too much for a

hunting scope!” The ranger wanted me to get him a scope for his .30-06, and we were discussing his options. Another Forest Service man overheard us and voiced this objection. We were both surprised, since the man had hunted for the first time in his life, with a borrowed rifle, just a few days before. I asked him, “Why d o you say that?’

“When I looked for that goat in the jcope the other day,” he said, “all I could see was hair.” I knew he’d gotten the goat nith one shot, so I knew he couldn’t have had too much trouble. I asked how far iway the goat had been, and his answer - ‘about as far as from here to that pickup” - put the range at well under fifty yards.

That fellow was the rankest beginner I ever saw, especially to be so lucky on his first goat hunt. He knew next to nothing about guns and less about scopes, but he taught me a lesson that has grown and flowered in the twenty-four years since. Four power was too much, and he had little enough gun prejudice and enough common sense to see it. I , influenced by the choices and judgment of others, had come to think it was some kind of gospel that a big-game rifle had to be equipped with a 4x scope of some sort. Unless it was a long-range outfit, in which case a 6x or sometimes higher power would be the best choice, Lower powers simply didn’t get included in my thinking.

The chief function of a scope is to make the target clearer, not seemingly bigger. It isn’t really bigger, no matter how large it looms up in the scope, so it isn’t any easier to hit. Magnification is necessary only when the apparent size of the target is too small to be easily seen - when the target itself is small or is far away, or both. Too much magnification restricts field of view (“all I could see was hair”), usually reduces usable eye relief and introduces more parallax, and exaggerates your view of your own utisteadiness of hold.

Especially with the lightly skilled shooter, this exaggerated wobble makes him try harder to hold steady on the target, making Tis wobble worse.

A friend visiting us the other day was talking about a 4x scope for a big-bore rifle he is working up. I suggested that he try instead a Weaver K-1.5, knowing what kind of use he intended for that rifle. He’d never seen one. so 1 trotted out one of

mine. The clarity, ease of holding, field of view, eye relief, and general excellence of that low-power scope amazed him, and he was instantly a convert to low-power scopes.

It’s too bad that Weaver’s old K-1 isn’t on the market any more. I’ve been trying to talk Weaver into reintroducing it, but without making the mistake of presenting it as a shotgun scope. I’m sure that’s what killed that superb old Weaver, which was about the best choice of sights I’ve ever seen for a really big rifle. The K-1, as you’ve already figured out, had n o magnification whatever.

Just a super-fancy iron sight, you say? No way. Look through a K-1, and you have to work hard to convince yourself that it doesn’t magnify the target. A small target ‘way off may need some magnification, so the K-1 won’t help much when you’re shooting prairie dogs at long range. But unless a moose, elk, or bear - or even a deer or coyote - is a mighty long way off, you won’t need magnification. Clarity is usually enough when such targets are within decent shooting range.

The K-1 is gone. Not for good, I hope; a friend at Weaver wants it brought back almost as badly as I do, so there may be a good outlook for it. I cherish-the one I have, and it will have a most special and useful perch atop a certain big-bore of mine that’s in the works now.

But there are many good choices available, between the not-to-be-had-now K - 1 and the .nearly universal 4x. Several outfits make 21/2xs, z3/4xs, and 3xs. A Leupold 3x - about as good a general hunting scope as any reasonable person could want - is the scope waiting to go on my .338 RCBS. As is fitting for a scope and rifle of such dignity, a Len Brownell mount will mate the two. Several of my rifles, especially those meant for or limited to brush and short-range use, are set up with another fine old classic (which is still with us), the z3/4x Redfield.

For coyote or antelope, my .25-06, .280 RCBS, and a couple of others have 4x or higher-powered scopes. Varmint rifles are set up with 6x, Bx, or more powerful scopes, but the need for magnification is obviously greater with this kind of rifle-and- scope combination.

Don’t take my word for it - but don’t pooh-pooh what I say, either. Try some of the lower powers, particularly in fixed- power scopes, and let them show you just how great they are. And if you wind up as

RIFLE 71

,

enthusiastic about them as I am, write Dan Flaherty at Weaver and put in a word for the reintroduction of the K-1. -’ Ken Howell

Conetrol Again Since writing my rather cautious review

of Conetrol scope mounts in the last issue (Rifle 70), I’ve had the twin benefits of a closer look at them and some testimony from a number of highly satisfied - though not easy to please - users of this beautiful mount. Typical is what one fellow phrased this way: “At first, the rings were ‘nuisances to handle and to attach.’ After much fumbling and uncomplimentary remarks about the ancestry of the inventors, I decided that I had tried everything, nothing worked, and all was lost as far as Conetrol mounts were concerned. But I discovered that the major problem was my unfamiliarity with these unique rings. Since then, I have had no difficulty installing them.”

George Miller, the genius “father” of the Conetrol, also pointed out something that hadn’t been obvious to me: that in the Conetrol, a scope is held very tightly by both rings rather than with one tight and one not-so-tight ring, which he tells me isn’t unusual in some other mounts. Yet another good point has made itself obvious to me; it has to do with what I thought might be less than perfect strength in the attachment of the ring to the base. Let me explain.

If 1 nail a vertical board to a rafter - to support a heavy weight, such as a shelf of tools - the strength of that attachment isn’t the one or two nails holding the vertical support hard against the rafter; the great friction between the two pieces of wood is what holds the weight. The nails align and clasp, and may also bear some of the weight, but it’s the lack of slip between the boards that gives them a strong weight- bearing ability.

On the Conetrol, the cone-tipped setscrews tighten on the stem at the base of the ring, into conical dimples on both sides of the stem, and cam the ring down hard against the base. This, I’m convinced, puts a terrific friction between ring and base, so that the tightly bound pair have a very high resistance to the inertia of recoil. Mounts with front rings that dovetail into the front base have something of the same kind of friction - in the front, not in the back, where a couple of clasping screws hold the rear ring down against the base with what I suspect isn’t as great a grip.

The attachment of the ring to the base struck me at first as not all that stout - but the more I study this design, the more strength there seems to be in this system. Which is to say that the more I see of them, the more I like them, and I haven’t yet seen the version with the ring halves held together at the bottom by‘a clamping screw. That one should be even nicer. - Ken Howell 0

SEPTEMBER-OCTOBER 1980

at Hornady WHEN you open a box of Hornady Match bullets, you’ll find not only a premium match bullet, but a lot of care and confidence as well. It’s put there by the “Matchmakers” at the Hornady plant in Grand Island, Nebraska. They’re dedicated shooters, too.. .interested in help- ing you score better and keenly aware of what it takes to do the job. They know that uniformity is the key to accuracy in bullet produc- tion ... and that every step in the Hornady bullet making process must be performed with unvarying precision. Every jacket must be drawn to the exact same thickness.. .every tiny point must be carefully formed and the concentricity of the projectile must be maintained.

Joyce Hornady said it best “Accuracy is our business and it doesn’t just happen. You. have to make it happen by minding those few thousandths or ten thousandths of an inch.”

Hornady makes 113 bullets for handloading and 5 of these bear the exclusive MATCH label. Pick one of them for your next competitive shoot.

22 cal. I 7MM 30 cal. I New National Match

52 gr. BTHP 53 gr. HP I 162 gr. BTHP

168 gr. BTHP

ornady Hornady Manufacturing Co. Dept. R-9 BUllefs Box 1848 Grand Island, Nebr. 68801

7

Roadors*

lY

$19.5

described

Stuart by

0 t teson

HE SIZES and weights of the six T actions covered so far in this series lie within what might be considered conventional limits for a varmint-class rifle. Except for the Shilen DGA, which tips the scales at about three pounds, they all fall within a span of 2 to 2Yz-pounds and have a diameter, or equivalent cross-section, somewhere between 1.35 and 1.40 inches (again with one exception, the Stolle Panda, where the use of aluminum allowed larger exterior dimensions).

The two action designs featured here fall distinctly outside these limits, thus representing more or less extreme approaches to the construction of a varmint rifle. They are both takeoffs from actions previously covered, and thus descriptions of their internal mechanisms, as well as the methods used to make them, won’t be repeated here. The Hall Model B is simply a standard Hall action (Rifle 66) with a greatly

Hall Model B specifications

length. . . . . . . . . . . . . . . . . . . . . . . . . ,8.0 inches weight . . . . . . . . . . . . . . . . . . . . . . . . 56 .8 ounces receiver diameter . . . . . . . . . . . . . . . . 1.745 inches barrel tenon. . . . . . . . 1-16 threads, 1.20 inches long bolt diameter . . . . . . . . . . . . . . . . . . . . . 0.87 inch depth of bolt-face counterbore. . . . . . . . . 0.127 inch bolt rotation . . . . . . . . . . . . . . . . . . . . . 90 degrees bolt travel . . . . . . . . . . . . . . . . . . . . . . . 3.3 inches firingpin fall (to impact). . . . . . . . . . . . . . 0.18 inch lock time . . . . . . . . . . . . . . . . . . . 2.0 milliseconds diameter of striker tip. . . . . . . . . . . . . . . 0.070 inch manufacturer . . . . . . . . . . . Hall Manufacturing

1910 Sunridge Carrollton, Texas 75006

2 2

enlarged receiver. The Shilen BP actions, in contrast, are drastically trimmed-down versions of the standard DGA single-shot action (Rifle 70).

Hall Model B

At first impression, the Model B action may seem a rather disproportioned design, too fat for its length and seemingly out of place in a varmint rifle. After being properly built into a 13Yz-inch rifle, however, and carefully considering the advantages that such a “maximum” action can offer, the Model B (Big Action) gains more and more credence. The initial impression of fatness and stoutness is soon replaced by an appreciation of its enormous strength and massiveness, as one becomes accustomed to the idea of an action of this proportion in a varmint rifle.

As the photographs make evident, this beautifully precision stainlesssteel receiver has to be just about the stiffest ever put on a varmint rifle. Its large diameter gives a mtdd-section rigidity of 10.1 x lo6 square- inch-pounds, ’way beyond anything

possible in a receiver of conventional size. It is in fact about four times as rigid as the solid-bottomed 40XBR and alrriost twice as rigid as the massive square-bottomed Shilen DGA.

Introduced in 1979, the Model B is 1.75 inches in diameter, compared to 1.37 inches in the standard Hall action. Even though it uses the same bolt, its receiver is also an inch longer than the standard action. Half an inch of this is accounted for at the front in the form of longer barrel threads, the rest at the rear as a longer tang.

The increased amount of metal in the receiver walls allowed Hall to redo his bolt stop slightly. It is removable from the top, without requiring access from underneath through the stock. Thus it is even slightly better adapted than the standard action to the glue-in approach, which Hall so strongly favors.

The Model B makes a lot of sense in these days of fiberglass stocks and light internal- adjustment scopes, where a lot of competitors actually end up stuffing lead into their stocks to bring heavy varmint

RIFLE 71

On the husky Hall action, the bolt-stop screw enters from above, so there i s no need to drill the stock for access. Scope mount i s attached by 6-48 screws. Massive proportions of the Model B’s receiver make it unique among actions designed for making Varmint-class rifles. Only the size of i ts receiver distinguishes the Model B from a standard Hall action.

rifles up to weight for better control and stability on sandbags. Use of a heavy action is a lot more logical approach to adding weight. And according to Hall, if you stick to the Lyman All-American or Leupold internal-adjustment scopes, and fiberglass stocks, the Model B easily makes the 13%- pound limit without sacrifice in the dimensions of the barrel. Thus, although originally contemplated as primarily a big gun action, now more than half of those sold are going into heavy varmint rifles. The 10Yz-pound classes are of course another story and require a lighter action.

Shilen BPand BP-S- SEPTEMBER-OCTOBER 1980 23

On Shilen BP and BP-S, alumi- num trigger guards save weight; stubby tangs omit location for rear guard screw. Receiver is turned down to make a very trim action, with bottom scalloped to provide better stability in the bedding. Tang is bobbed off flush with rear of the bolt sleeve.

Shilen BP and BP-S Shilen’s BP (Bench Pistol) actions,

officially designated the DGA/BP and DGA/BP-S, came into being by an essentially opposite process. Whereas Hall enlarged an existing design, Shilen shrank his rather massive DGA to produce a much lighter and trimmer action. While the BP actions, introduced in 1978, were obviously developed with an eye toward the silhouette-pistol market, they can also make into a suitable varmint-class rifle for someone desiring to utilize a lot of barrel and stock weight, particularly in the 10% pound classes.

Shilen originally went to his big square- bottom DGA receiver for bedding stability in a wood stock. Even when it is “glassed,” he felt that the susceptibility of wood to compression always strongly favored a pattern with a very broad, flat bottom surface. According to Shilen, however, the compression strength now available in fiberglass stocks largely eliminates this

Shilen BP specifications

length. . . . . . . . . . . 7.49 inches(with recoil bracket) weight. . . . . . . . . . . . . . . . . . . . . . . . 32.6 ounces receiver diameter . . . . . . . . . . . . . . . . 1.304 inches barrel tenon . . . . . 1-1/16-18 threads, 0.96 inch long bolt diameter . . . . . . . . . . . . . . . . . . . . 0.725 inch depth of bolt-face counterbore. . . . . . . . . 0.130 inch bolt rotation . . . . . . . . . . . . . . . . . . . . . 90 degrees bolt travel . . . . . . . . . . . . . . . . . . . . . . . 3.9 inches firing-pin fall (to impact). . . . . . . . . . . . . . 0.28 inch lock t ime . . . . . . . . . . . . . . . . . . . 2.4 milliseconds diameter of striker t ip. . . . . . . . . . . . . . . 0.072 inch manufacturer . . . . . . . . . . . Shilen Rifles, Inc.

205 Metro Park Blvd. Ennis, Texas 75119

problem and makes the smaller round- bottom receiver entirely practical.

There was also a purely practical basis for the existence of the BP actions. The cost of receiver castings has been rising sharply over recent years, and the BP represented a way to salvage borderline DGA castings, which were sound except for small blemishes on the finished exterior surfaces. Thus while it might be considerably smaller than the DGA, a BP receiver starts out from the same size casting, and can in fact have more machining time in it. Many have undergone exterior milling to produce a square DGA pattern, only to be then mounted in a lathe and converted to a cylindrical BP pattern.

Shilen BP-S specifications

length. . . . . . . . . . . 6.53 inches (with recoil bracket) weight . . . . . . . . . . . . . . . . . . . . . . . . 27.8 ounces receiver diameter . . . . . . . . . . . . . . . . 1.308 inches barrel tenon . . . . . 1-1/16-18 threads, 0.96 inch long bolt diameter . . . . . . . . . . . . . . . . . . . . 0.723 inch depth of bolt-face counterbore. . . . . . . . . 0.128 inch bolt rotation . . . . . . . . . . . . . . . . . . . . . 90 degrees bolt travel . . . . . . . . . . . . . . . . . . . . . . . 3.2 inches firing-pin fall (to impact). . . . . . . . . . . . . . 0.26 inch lock t ime . . . . . . . . . . . . . . . . . . . 2.6 milliseconds diameter of striker t ip. . . . . . . . . . . . . . . 0.072 inch manufacturer . . . . . . . . . . . Shilen Rifles, Inc.

205 Metro Park Blvd. Ennis, Texas 75119

It might be interesting to examine a practical aspect of making firearms with investment castings. The wax-pattern die for a receiver alone runs today around ten thousand dollars, a figure that certainly won’t make or break a company like Ruger but which is of enormous significance for an operation the size of Shilen Rifles. Thus while Shilen’s line of actions now features five distinct receivers, they all start-out from the same die that Shilen uses for the original DGA action.

While the round versions are produced by simply hogging down the big square castings on a lathe, there are also three basic receiver lengths (short, medium, and magnum), which result from a slightly more imaginative process. To produce a short receiver, a section about an inch long is simply sliced from the middle of the wax pattern produced from the die. The front and rear wax sections that remain are then carefully glued back together, and the ceramic mould is made from this.

The section cut from the middle in the above procedure is not thrown away but saved to use as a “transplant” in making magnum-length receivers. Another wax pattern is cut through the middle, but this time instead of removing material, the extra piece is glued in place to stretch out its length.

As the photographs illustrate, there is an enormous contrast in sizes and thicknesses between Hall’s Model B and Shilen’s BP series. With a 1.3-inch receiver diameter and l-1/16-inch barrel threads, only about an eighth of an inch of metal surrounds the

24 RIFLE 71

SHILEN BP

SEPTEMBER-OCTOBER 1980 25