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Vortex Viper HS 4-16×50 LR instruction manual


This text is a transcription of the file in PDF format.

The Vortex®Viper®HS LR™ riflescopes are intended for dedicated long range hunters. Using a specially designed uncapped, rapid travel elevation turret with our CRS zero stop, this riflescope accommodates the unique needs of hunters who prefer to “dial in” elevation adjustments for long range shots. The Viper HS LR series riflescopes also provide an ideal platform for the optional Vortex TMT custom turret caps.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR


The Focal Plane

All riflescope reticles can be termed either first focal plane (FFP) or second focal plane (SFP), depending upon their internal location within the riflescope. This model features the first focal plane design.

Second Focal Plane Reticles

Second focal plane (SFP) reticles are located near the scope’s 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.

Listed reticle subtensions used for estimating range, holdover, and wind drift correction are accurate at the highest magnification. Note: Listed BDC reticle subtensions for a 6–24×50 model are accurate with the magnification set at 18x.

Vortex Viper HS 4-16×50 LR
Vortex Viper HS 4-16×50 LR


Reticle Focus

The Viper HS LR riflescope uses a fast focus eyepiece designed to quickly and easily adjust the focus on the riflescope’s reticle.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

To adjust the reticle focus:

  • Look through the riflescope at a blank white wall or up at the sky.
  • Turn the eyepiece focus knob in or out until the reticle image is as crisp as possible.
  • Note: Try to make this particular adjustment quickly, as the 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 riflescope. However, because your eyesight may change over time, you should re-check this adjustment periodically.


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

Windage and Elevation Adjustments

The Vortex Viper HS LR riflescope incorporates precision finger adjustable elevation and windage dials with audible clicks.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

To make adjustments:

  1. Turn the adjustment knob in the appropriate direction: Up/Down or Left/Right as indicated by the arrows.
  2. Following the directional arrows, turn the knobs in the direction you wish the bullet’s point-of-impact to go to.

Note: After sight-in, you can re-align the zero marks on the turret knobs with the reference dots if you wish (see Indexing Adjustment Dials with Zero Reset on page 15). Replace outer covers when done.

MOA Adjustments

The Viper HS LR riflescopes use finger adjustable elevation and windage turrets with scales measured in minutes of angle (MOA). MOAs are a unit of arc measurement which equals 1.05 inch for each 100 yards. Examples: 2.1 inches @ 200 yards, 3.15 inches @ 300 yards, etc.

The tactical-style elevation turret is designed to provide a high travel range along with rapid adjustment ability. Each click will provide ½ MOA of reticle movement (approximately ½-inch @ 100 yards).

The windage turret uses a standard design with an external cap. Each click will provide ¼ MOA of reticle movement (approximately ¼-inch @ 100 yards).

Turret Rotation

Vortex Viper HS LR riflescopes incorporate Vortex’s patented Radius Bar to visually assist in keeping track of turret rotations. The Radius Bar provides a quick visual reference that allows the shooter to confirm:

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR
  • Knob orientation is correct and has not shifted as a result of accidental contact.
  • Knob orientation is at the zero point when using the CRS feature.
  • By watching the position of the bar while making elevation adjustments, the shooter is 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 14).

Variable Power Adjustments

To change the magnification, turn the magnification ring to the desired level. The Vortex fiber optic magnification indicator will provide a low light reference for magnification level.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Customizable Rotational Stop (CRS)

Viper HS LR riflescope elevation turrets incorporate the unique CRS rotation stop feature. After the rifle is sighted in, the design of the CRS allows a shooter to quickly and easily return to an original zero point when using the elevation turret to dial-in temporary bullet drop corrections.

The CRS feature is particularly useful when dialing large multi-revolution elevation corrections. Without this feature, the shooter must pay very careful attention when dialing these large corrections. If the shooter loses track of the number of revolutions, the original zero point may become lost when returning the adjustment. Viper HS LR riflescopes equipped with the CRS allow the elevation dial to be quickly spun back to original zero without having to carefully count revolutions or clicks.

Once the CRS shims are installed after sight-in, the elevation dial will stop turning shortly past the original zero point when being returned (turning clockwise direction) from a temporary elevation adjustment. The shooter can then turn the elevation knob a partial turn in a counterclockwise direction until the zero reference and radius bar are correctly aligned—achieving the original zero point.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Using the Side Focus

Viper HS LR riflescopes use a side focus adjustment which provides maximum image sharpness and eliminates parallax error.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Setting the side focus:

  1. Be sure the reticle is correctly focused (see Reticle Focus on page 5).
  2. Turn the side focus knob until the target image is as sharp as possible. The yardage numbers referenced on knob should closely match the actual yardage to the target.
  3. Check for parallax error by moving your head back and forth while looking through the scope. The focus is correct if there is no apparent shift of the reticle on the target. If you notice any shift, adjust the focus knob slightly until all shift is eliminated.

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 the shooter’s 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.


To get the best performance from your Viper HS LR riflescope, proper mounting is essential. Although not difficult, the correct steps must be followed. If you are unsure of your abilities, it would be best to use the services of a qualified gunsmith.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Rings and Bases

Mount an appropriate base and matching rings to your rifle according to the manufacturer’s instructions. The Vortex Viper HS LR riflescopes require 30 mm rings.

Use the lowest ring height that will provide complete clearance of scope and rifle—avoiding any contact with barrel, receiver, bolt handle or any other part of the rifle. A low mounting height will help assure proper cheek weld, aid in establishing a solid shooting position, and promote fast target acquisition.

Eye Relief and Reticle Alignment

After installing the bottom ring halves on the mounting base, place the riflescope on the bottom ring halves and loosely install the upper ring halves. Before tightening the scope ring screws, adjust for maximum eye relief to avoid injury from recoil:

  1. Set the riflescope to the middle of its magnification range.
  2. Slide the riflescope as far forward as possible in the rings.
  3. While viewing through the riflescope in a normal shooting position, slowly slide the riflescope back towards your face. Pay attention to the field of view. Stop sliding the riflescope back as soon as you see the full field of view.
  4. Without disturbing the front-back placement, rotate the riflescope until the vertical crosshair exactly matches the vertical axis of the rifle. Use of a reticle leveling tool, a weight hung on a rope, flat feeler gauges, or a bubble level will help with this procedure.

After aligning the reticle, tighten and torque the ring screws down per the manufacturer’s instructions.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Bore Sighting

Initial bore sighting of the riflescope will save time and money at the range. This can be done in a number of ways. A mechanical or laser bore sighter can be used according to the manufacturer’s instructions. On some rifles, bore sighting can be done by removing the bolt and sighting through the barrel.

To visually bore sight a rifle:

  • Place the rifle solidly on a rest and remove the bolt.
  • Sight through the bore at a target approximately 100 yards away.
  • Move the rifle and rest until the target is visually centered inside the barrel.
  • With the target centered in the bore, make windage and elevation adjustments until the reticle crosshair is also centered over the target.
Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Final Range Sight-In and CRS Stop-Set

After the riflescope has been bore-sighted, final sight-in and CRS stop-set should be done at the range. Sight in and zero the riflescope at the preferred distance using the exact ammunition expected to be used while shooting. 100 yards is the most common zero distance, although a 200 yard zero may be preferred for long range applications.

Note: Be sure the reticle is in focus (see Reticle Focus on page 5) and set the side focus adjustment to match the distance being used for sight-in:

  1. Following all safe shooting practices, fire a three-shot group as precisely as possible.
  2. Next, adjust the reticle to match the approximate center of the shot group (see Windage and Elevation Adjustments on page 6).
    Note: If the rifle is very solidly mounted and cannot be moved, simply look through the scope and adjust the reticle until it is centered on the fired group.
  3. Carefully fire another three-shot group and see if the bullet group is centered on the bullseye.

This procedure can be repeated as many times as necessary to achieve a perfect zero.

Setting the CRS Stop and Indexing Elevation Knob

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

  1. Loosen the three turret cap retaining screws on the elevation turret. Gently pull the turret cap straight up and off of the turret post—being 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.

    Vortex Viper HS 4-16x50 LR
    Vortex Viper HS 4-16×50 LR
  3. After filling the center gap on the post with shims, replace the elevation cap.
  4. Align the turret cap so the “0” mark on the cap matches up with the “0” reference line on the turret post. Again, be sure not to rotate the actual turret mechanism in the process.
  5. Re-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.

Indexing Windage Dial with Zero Reset

Viper HS LR riflescopes feature 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 in this way:

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

Using the CRS Zero Stop

Once the CRS shims are installed, the elevation dial will stop turning shortly past the original zero point when being returned (turning clockwise direction) from a temporary elevation adjustment.

Vortex Viper HS 4-16x50 LR
Vortex Viper HS 4-16×50 LR

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



The fully waterproof and fogproof Viper HS LR riflescope 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, such as the Vortex Fog Free cleaning products or LensPen, that are specifically designed for use on coated optical lenses.

  • Be sure to blow away any dust or grit on the lenses prior to wiping the surfaces.
  • Using your breath, or a very small amount of water or pure alcohol, can help remove stubborn things like dried water spots.


All components of the Viper HS LR riflescopes 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 riflescope. Disassembling of riflescope may void warranty.


If possible, avoid exposing your Vortex riflescope to direct sunlight or any very hot location for long periods of time.


Sighting-in Problems

Many times, problems thought to be with the scope are actually mount problems. Be sure that correct base and rings are being used in the correct orientation, and that the base screws and rings are tight. Insufficient windage or elevation adjustment range may indicate problems with rings, base, base alignment, base mount holes drilled in the rifle’s receiver, or barrel/receiver alignment.

Check for Correct Base and Ring Alignment

  • Roughly center the reticle by adjusting both windage and elevation turrets to the mid point of their travel ranges.
  • Attach bore sighter, or remove bolt and visually boresight rifle.
  • Look through the scope. If the reticle appears way off center on the boresighter image or when compared to the visually centered target when looking through rifle’s bore, there may be a problem with the bases or rings being used. Confirm that correct base and rings are being used—and in the proper orientation.

Tips for Solving Bullet Grouping Problems

  • Maintain a good shooting technique and use a solid rest.
  • Check that all screws on rifle’s action are properly tightened.
  • Be sure rifle barrel and action are clean and free of excessive oil or copper fouling.
  • Check that rings are correctly torqued per the manufacturer’s instructions.
  • Some rifles and ammunition don’t work well together—try different ammunition and see if accuracy improves.


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 HS LR riflescope becomes damaged or defective, Vortex Optics will repair or replace the riflescope at no charge to you. Call Vortex Optics at 800-426-0048 for prompt, professional, and friendly service.

Vortex Optics
2120 West Greenview Drive
Middleton, WI 53562
[email protected]

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

Vortex Optics believes strongly in responsible, ethical hunting and a word should be said about long range shooting at game. Although riflescopes, like the Vortex HS LR series, 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 at game. Please be responsible—the keys are knowing your rifle, ammunition and your own abilities!



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