The VorTex® Viper® xBr™ CrossBow sCope

The Vortex®Viper®XBR™ crossbow scope is intended for extended range crossbow shooting. With the XBR, you have the unique ability to choose between using the elevation turret or the reticle when compensating for arrow drop on long shots.

Dual Use: Shooting Tactical / Hunting

US Patent 7,937,879

— Please read entire manual before using your new optic.

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ObjectiveLens

Fast Focus Eyepiece

MagView ElevationAdjustment Dial

Windage Adjustment Dial

Magnification Adjustment Ring

Reticle Focus

IlluminationAdjustment Dial

reTiCle opTionsThe Focal Plane

All scope reticles can be termed either first focal plane (FFP) or second focal plane (SFP) according to the internal location of the reticle within the scope. This model features a second focal plane reticle design.

Second Focal Plane Reticles

Second focal plane reticles are located near the eyepiece behind the image erecting and magnifying lenses. This style of reticle does not visually change in size when you change the magnification. The advantage of an SFP reticle is that it always maintains the same ideal visual appearance.

Important Note: The marked Viper XBR 2.5-10x44 crossbow scope reticle subtensions used for arrow drop and wind drift compensation are correct at a magnification of 10x.

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CrossBow sCope AdjusTmenTsReticle Focus

The Viper XBR crossbow scope features a fast focus eyepiece designed to quickly and easily adjust the reticle focus.

To adjust the reticle focus:

1. Look through the scope at a blank white wall or up at the sky.

2. Turn the eyepiece focus knob in or out until the reticle image is as crisp as possible.

TIP: Try to make this particular adjustment quickly as your eye will try to compensate for an out-of-focus reticle.

Once this adjustment is complete, it will not be necessary to re-focus every time you use the crossbow scope. However, because your eyesight may change over time, you should re-check this adjustment periodically.

Warning

Looking directly at the sun through a crossbow scope, or any optical instrument, can cause severe and permanent damage to your eyesight.

Adjust the Reticle Focus

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Windage and Elevation Adjustments

The Viper XBR scope features precision finger-adjustable elevation and windage dials with audible clicks.

To make adjustments:

1. Following the directional pointer on the turret cap, turn the dial in the direction you wish the arrow’s point-of-impact to go: up or down, left or right.

2. Replace the outer cover on the windage turret when done.

TIP: After sight-in, you can re-align the zero marks on the windage turret dial with the reference dots if you wish (see Indexing the Windage Dial with Zero Reset on page 18).

MOA Adjustments

The Viper XBR crossbow scope uses finger adjustable elevation and windage turrets with scales measured in minutes of angle (MOA). MOAs are a unit of angular measurement which approximately equals one inch at 100 yards.

• The tactical-style elevation turret design provides a high travel range along with rapid adjustment ability. Each click of the elevation turret will provide 1 MOA of reticle movement.

• The windage turret features a standard design with an external cap. Each click of the windage turret will provide 1 MOA of reticle movement.

Elevation Dial

Windage DialMOA at Common DistancesRemember that one click of the turret equals 1 MOA.

1 MOA = 1 inch at 100 yards

1/2 inch at 50 yards

1/3 inch at 33 yards

1/4 inch at 25 yards

1/5 inch at 20 yards

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Turret Rotation

Vortex’s patented Radius Bar visually assists keeping track of turret rotations and provides a quick visual reference that allows you to confirm:

• Dial orientation is correct and has not shifted as a result of accidental contact.

• Dial orientation is at the zero point when using the CRS feature (see page 10).

TIP: By watching the position of the bar while making elevation adjustments, you are able to quickly track full, half, and quarter rotations.

To get these benefits from the Radius Bar, the “0” mark on the turret must be indexed with the zero reference line on turret post (see Setting the CRS Stop and Indexing Elevation Knob on page 17).

Radius Bar

Variable Power Adjustments

To change the magnification, turn the magnification ring to the desired level. The MagView fiber optic magnification indicator provides a low light reference for magnification level. A small tactile indent at the 5x magnification setting allows you to quickly select 5x.

Illumination Adjustments

The Viper XBR scope features a reticle illumination system with variable levels of intensity to aid in low light performance.

To activate the illumination, rotate the adjustment dial in either direction. This illumination dial allows for 10 levels of brightness intensity; an off click between each level allows you to turn the illumination off and return to a favored intensity level with just one click.

Replacing the Battery

1. Unscrew the outer cap with a coin.

2. Remove the battery.

3. Replace with a new CR 2032 battery.

4. Re-install the outer battery cap and be sure to fully tighten it.

MagView

Indicator

Battery Cap

IlluminationAdjustmentDial

MagnificationAdjustment Ring

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Customizable Rotational Stop (CRS)

The elevation turret on the Viper XBR crossbow scope features the unique CRS rotation stop. After sighting in the crossbow, the CRS allows you to quickly and easily return to an original zero point after dialing in arrow drop corrections.

The CRS feature is particularly useful when dialing large multi-revolution elevation corrections. The CRS allows you to quickly spin the elevation dial back to the original zero without having to carefully count revolutions or clicks.

See how to install CRS shims in the Setting the CRS Stop and Indexing Elevation Dial section on pages 17–18.

CRS Shims

Focus and Parallax

Parallax is a phenomenon that results when the target image does not quite fall on the same optical plane as the reticle within the scope. When your eye is not precisely centered in the eyepiece, there can be apparent movement of the target in relation to the reticle which can cause a small shift in the point-of-aim. Parallax error is most problematic for precision shooters using high magnification.

The Viper XBR crossbow scope is factory-focused at 75 yards and will have minimal parallax at distances from 35 to 125 yards. At distances closer than 30 yards, there may be a very slight shift of the reticle on the target (parallax) if your eye is not centered directly behind the scope’s eyepiece. This shift can be eliminated by keeping your eye centered behind the scope when shooting.

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CrossBow sCope mounTing

The XBR scope requires 30 mm mounting rings of a medium or high height. Most modern crossbows have a pre-installed Weaver base, so your ring choice should be compatible with this type of base.

Due to the typically short stock used on crossbows, Vortex Optics highly recommends using at least one cantilever or extension ring in combination with a standard ring when mounting your scope. This combination allows the scope to be placed in a more forward position than possible when only using standard rings and provides the optimal sight picture. Be sure the rings are identical in height.

TIP: For specific ring recommendations, please refer to the Viper XBR product page at www.vortexoptics.com.

Eye Relief and Reticle Alignment

Install the bottom ring halves on the mounting base. Place the crossbow scope on the bottom ring halves and loosely install the upper ring halves. Before tightening the scope ring screws, adjust for comfortable eye relief:

1. Set the scope to the middle of its magnification range.

2. Slide the scope as far forward in the rings as possible.

3. Look through the scope while in your normal shooting position and slowly slide the scope towards your eye. Stop sliding the scope when you see the full field of view.

4. Without disturbing the front-back placement, rotate the scope until there is an exact match between the vertical crosshair of the reticle and the vertical axis of the crossbow. Use a reticle leveling tool, a weight hung on a rope, flat feeler gauges, or a bubble level to help with this procedure.

After aligning the reticle, tighten and torque the ring screws down per the manufacturer’s instructions. As a general rule, Vortex Optics recommends torquing the ring screws to 16 in/lbs.

Use bubble levels to square the crossbow scope to the base. Shown on a Scorpyd reverse draw crossbow.

Due to typically short stocks used on crossbows, Vortex highly recommends using a cantilever ring with the Viper XBR scope.

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sighTing in The xBr CrossBow sCope

For the best long-range ability, Vortex recommends a 30-yard zero on the center crosshair. Begin the initial sight-in at a distance of 8 yards. Due to arrow trajectory, this will also closely equal the desired 30-yard zero. Points of impact between 8 and 30 yards will be just slightly high and may be compensated for by holding point of aim on the first reticle tick above center. Once you have mounted your XBR scope, use either the reticle or ruler method to sight in your scope.

Sight In Method Using the ReticleStep 1

While looking through the scope, use the reticle hashmarks to measure the distance the arrow missed the bullseye. Set the magnification to 2.5x then aim and shoot for the bullseye at a distance of 8 yards. Try to keep your eye centered behind the eyepiece in order to reduce the effects of parallax at this very close range. Most likely, you will not hit the bullseye with this initial shot. Important Note: Hashmarks as seen in the reticle are marked in increments of 5 MOA, but at 2.5x these increments actually span 20 MOA.

Example

When looking through the scope, the arrow strike is 1 hashmark high and 2 hashmarks to the right of center.

1. Calculate amount of adjustment needed: Elevation: 1 x 20 MOA = 20 MOA Windage: 2 x 20 MOA= 40 MOA

2. Adjust the turrets (each click equals 1 MOA): Elevation: Rotate turret down 20 clicks. Windage: Rotate turret left 40 clicks.

3. Shoot another arrow to check adjustment. Repeat as necessary.

Sight In Method Using a RulerStep 1

Use an inch-based ruler to measure the distance your arrow misses the bullseye. Set the magnification to 2.5x, then aim and shoot from a distance of 8 yards. Try to keep your eye centered behind the eyepiece in order to reduce the effects of parallax at this very close range.

1. Measure the distance your arrow missed the bullseye in inches. Divide your measurement by .08 to convert to MOAs. At 8 yards, one MOA equals .08 inches and each turret click adjusts the point-of-impact .08 inches.

2. Rotate the turret to move the appropriate number of MOAs in the direction you wish the arrow’s point-of-impact to move.

Step 2

Due to trajectory arc, the initial 8-yard zero will closely correspond to the desired final 30-yard zero. Move the target back to 30 yards, adjust the scope to a magnification of 5x and shoot another arrow at the bullseye. Be sure to keep your eye centered behind the eyepiece.

Example

Looking through the scope, the arrow strike is 1 hashmark low and 1.5 hashmarks left of the bullseye. Important Note: Hashmarks as seen in the reticle are marked in increments of 5 MOA, but at 5x these increments will span 10 MOA.

1. Calculate amount of adjustment needed: Elevation: 1 x 10 = 10 MOA Windage: 1.5 x 10= 15 MOA

2. Adjust the turrets (each click equals 1 MOA): Elevation: Rotate the turret up 10 clicks. Windage: Rotate the turret right 15 clicks.

3. Shoot another arrow to check adjustment. Repeat as necessary.

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1. Loosen the three turret cap retaining screws on the elevation turret and gently pull the turret cap straight up and off of the turret post. Be careful not to rotate the turret post.

2. Slide the CRS shims on the center section of the turret post below the V-grooved part.

3. Alternate the shim installation direction 180 degrees with each shim. Use only as many shims as necessary to completely fill the space. If a shim does not fit, do not force it in place.

4. After filling the center gap on the post with shims, replace the elevation cap.

5. Align the turret cap so the “0” mark on the cap lines up with the “0” reference line on the turret post. Don’t rotate the actual turret mechanism in the process.

6. Tighten the retaining screws, but do not overtighten. Use of thumb and forefinger on the short end of the hex wrench will provide sufficient force.

Setting the CRS Stop and Indexing Elevation Dial

After obtaining a satisfactory zero, the CRS stop can be set using the following technique:

Step 2

Due to trajectory arc, the initial 8-yard zero will closely correspond to the desired final 30-yard zero. Move the target back to 30 yards, adjust the scope to a magnification of 5x and shoot an arrow at the target center. Be sure to keep your eye centered behind the eyepiece.

Example

Measuring on the target, the arrow strike is 1.2 inches low and 1.8 inches left of center. Important Note: One MOA will equal .3 inches at 30 yards.

1. Calculate amount of adjustment needed: Elevation: 1.2 ÷ .3 = 4 MOA Windage: 1.8 ÷ .3 = 6 MOA

2. Adjust the turrets (each click equals 1 MOA): Elevation: Rotate the turret up 4 clicks. Windage: Rotate the turret right 6 clicks.

3. Shoot another arrow to check adjustment and repeat as necessary.

Place the CRS shims in this groove.

Once the clearance is tight, do not try to force in another shim.

Example

The arrow strike is 2 inches high and 4 inches to the right of center.

1. Calculate amount of adjustment needed: Elevation: 2 ÷ .08 = 25 MOA Windage: 4 ÷ .08 = 50 MOA

2. Adjust the turrets (each click equals 1 MOA): Elevation: Rotate the turret down 25 clicks. Windage: Rotate the turret left 50 clicks.

3. Shoot another arrow to check adjustment and repeat as necessary.

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Indexing the Windage Dial with Zero Reset

The Viper XBR scope features a windage dial that will allow you to re-index the zero indicator after sight-in without disturbing your settings. This allows you to quickly return to your original zero if temporary windage corrections are used in the field.

Index the windage dial as follows:

1. Remove the outer cap.

2. Pull the adjustment dial outward against the spring tension until it stops.

3. With the dial pulled fully out, rotate the dial to align the “0” with the etched indicator line on the scope.

4. Release the dial, allowing it to return to the normal inward position.

5. Replace the windage turret cap.

Pull dial outward to adjust.

Now, turn the elevation dial counter-clockwise until the Radius Bar is aligned so the scope axis and zero mark match. This setting will match the original zero point.

TIP: If re-zeroing at a future time, be sure to remove all CRS shims before sight-in.

Using the CRS Zero Stop

Now that you have installed the CRS shims, you can rotate the elevation dial clockwise and easily return to the original zero point after making a temporary elevation adjustment. The dial will stop turning just past the original zero.

Turn clockwise until the turret stops.

Turn counter-clockwise until the Radius Bar aligns with the zero mark on the scope body.

Align the “0” with the etched indicator line on scope.

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how To shooT AT long rAnge wiTh The xBrThink of arrow drop in MOAs, not inches.

The first step to successful long range crossbow shooting using the XBR is to learn to think of arrow drops in MOAs (not inches). This has the tremendous advantage of allowing you to easily and rapidly adjust the scope using either the MOA marks on the elevation turret or the MOA marks on the vertical crosshair.

Build a Drop Chart in MOAs.

After establishing a 30-yard zero, the second step is to build an MOA drop chart for your specific crossbow and arrow combination at increasing distances of 30, 40, 50, 60, 70 yards, etc.

1. Begin by choosing the sample chart and arrow speed that most closely matches your crossbow (see samples below and on page 22).

2. Dial up the suggested adjustment for the distance you are shooting.

3. Shoot at your target and measure how much the arrow hit above or below the bullseye in inches.

4. Calculate the MOAs by dividing your measurements by the value listed in the conversion chart on page 20 and adjust turrets accordingly.

• If arrow strikes low, add your calculated MOA value to chart value.

• If arrow strikes high, subtract your calculated MOA value from chart value.

5. Shoot again. When you hit the bullseye, record this final MOA adjustment for future use.

MOA markings on XBR-1 reticle.

Example

If your arrow has dropped 12 inches on a 50-yard shot, it has dropped 24 MOA.

12 ÷ .5 = 24 MOA

Conversion ChartUse the following values when

converting from inches to MOAs.

1 MOA = 1.0 inch at 100 yards

.9 inches at 90 yards

.8 inches at 80 yards

.7 inches at 70 yards

.6 inches at 60 yards

.5 inches at 50 yards

.4 inches at 40 yards

.3 inches at 30 yards

.2 inches at 20 yards

MOA markings on the XBR turret.

Sample Drop Charts

Drop Chart in MOAs

325 fps Adjustments

30 yards 0

40 yards 15 MOA

50 yards 30 MOA

60 yards 46 MOA

70 yards 63 MOA

Drop Chart in MOAs

360 fps Adjustments

30 yards 0

40 yards 12 MOA

50 yards 26 MOA

60 yards 41 MOA

70 yards 55 MOA

80 yards 71 MOA

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Correcting for Arrow Drop

After building your own MOA drop chart, you can correct for arrow drop by using either the reticle or the elevation turret correction method.

Arrow Drop Correction Using the Reticle

Compensating for arrow drop and wind drift using the reticle is quick and easy, and has a big edge in hunting situations because no game spooking hand motion is required. Simply choose your hold point on the reticle based on the range and your MOA drop chart and then shoot.

Using a reticle for arrow drop and wind drift compensation has one important limitation. In second focal plane scopes, such as the Viper XBR, reticles using drop lines are sensitive to magnification. The marked MOAs on the XBR-1 reticle are only correctly marked with the scope set at the highest magnification (10x). At 5x, actual MOAs will be twice what is marked on reticle; at 2.5x, actual MOAs will be four times what is marked on the reticle.

Using the following technique, the XBR-1 reticle will allow you to shoot effectively with your reticle at magnifications of 2.5x, 5x and 10x.

• If you are shooting with the scope set at 10x, all MOA markings on the reticle are correctly displayed as 10, 20, 30, 40, and 50 MOA.

• If you are shooting with the scope set at 5x, the actual drop values will be 20, 40, 60, 80, and 100 MOA.

• If you are shooting with the scope set at 2.5x, the actual drop values will be 40, 80, 120, 160, and 200 MOA.

Example

Your drop chart indicates you need a 20 MOA holdover to make your shot. With the scope set at 5x, you should hold on the 10 MOA reticle mark which yields the actual 20 MOA that you need.

Example Using a 360 fps Crossbow at a 40-Yard Distance

Shooting with the initial adjustment as suggested in the sample drop chart should allow you to hit the target, but you probably won’t hit the bullseye.

1. Dial up 12 MOA on the elevation turret then aim and shoot at the bullseye using the reticle crosshair.

2. Measure the distance your arrow hits above or below the bullseye in inches.

3. Divide your measurements by .4 to calculate value in MOAs (.4 comes from the conversion chart on page 20).

• If arrow strikes low, add your calculated MOA value to 12 MOA.

• If arrow strikes high, subtract your calculated MOA value from 12 MOA.

4. Shoot again. When you hit the bullseye, record this final MOA adjustment for future use.

5. Repeat process with targets set at distances of 50, 60, 70, 80 yards, etc.

TIP: Keep your adjusted MOA drop values handy for quick use in the field.

Drop Chart in MOAs

360 fps Adjustments

30 yards 0

40 yards 12 MOA

Drop Chart in MOAs

385 fps Adjustments

30 yards 0

40 yards 11 MOA

50 yards 23 MOA

60 yards 36 MOA

70 yards 49 MOA

80 yards 63 MOA

90 yards 77 MOA

100 yards 92 MOA

Drop Chart in MOAs

425 fps Adjustments

30 yards 0

40 yards 7 MOA

50 yards 16 MOA

60 yards 26 MOA

70 yards 37 MOA

80 yards 48 MOA

90 yards 59 MOA

100 yards 71 MOA

Sample Drop Charts

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Arrow Drop Correction Using the Elevation Turret

Using the elevation turret to adjust for arrow drop is slightly slower than using the reticle, and also entails some hand motion which could spook game. The advantage to making a turret adjustment is that it is not sensitive to the scope’s magnification and can be successfully used at any magnification. Simply turn the turret in the up direction the number of MOAs indicated on your drop chart, then shoot using the center crosshair.

Be aware that available turret travel up range may be limited by the alignment of the crossbow’s scope mounting rail. Most rails should allow at least 50 MOAs of available up travel when using the XBR’s elevation turret. If necessary, turret MOAs and reticle MOAs can be combined to achieve the required drop correction for very long shots.

Once you build your MOA drop chart, it is also possible to etch or tape a custom elevation turret marked in yards rather than MOAs. A yardage-marked turret allows quick adjustment in the field without needing to consult the MOA drop chart. If you are interested in doing this, please feel free to call our office at (800) 426-0048 or e-mail info@vortexoptics.com for options and assistance.

Consider adding a custom elevation turret marked in yards rather than MOAs.

mAinTenAnCeCleaning

The fully waterproof and fogproof Viper XBR scope requires very little routine maintenance other than periodically cleaning the exterior lenses. The exterior of the scope may be cleaned by wiping with a soft, dry cloth.

When cleaning the lenses, be sure to use products that are specifically designed for use on coated optical lenses such as the Vortex Fog Free cleaning products or LensPen.

• Be sure to blow away any dust or grit on the lenses prior to wiping the surfaces.

• Use your breath, or a very small amount of water, to remove dried water spots. Pure alcohol can help remove marks like fingerprints.

Lubrication

All components of the Viper XBR scope are permanently lubricated, so no additional lubricant should be applied.

Note: Other than removing the turret caps, do not attempt to disassemble any components of the scope. Disassembling the scope may void the warranty.

Storage

If possible, avoid storing your scope in direct sunlight or any very hot location for long periods of time.

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The Vip wArrAnTy

We build optics based on our commitment to your absolute satisfaction. That’s why Vortex products are unconditionally guaranteed and we make this Very Important Promise to you—a Very Important Person.

Rest assured that in the event your Viper XBR scope becomes damaged or defective, Vortex Optics will repair or replace the scope at no charge to you. If we cannot repair your product, we will replace it with a product in perfect working order of equal or better physical condition. Call Vortex Optics at 800-426-0048 for prompt, professional, and friendly service.

Vortex Optics

2120 West Greenview Drive

Middleton, WI 53562

service@vortexoptics.com Lifetime Warranty

Unlimited Unconditional

Vortex Optics believes strongly in responsible, ethical hunting. Although scopes can make long distance shots much easier, there are still many other variables, such as wind, affecting every shot. It is important for hunters shooting at long distances to learn their personal, effective range, particularly in windy conditions, and to not shoot beyond those distances.

Visit www.vortexoptics.com for more information. Canadian customers may visit www.vortexcanada.net for customer service information.

Note: The VIP warranty does not cover loss, theft or deliberate damage to the product.