vortex viper pst 6-24x50 moa rifle scope manual - EuroOptic.com

Parallax AdjustmentThis model of the Viper PST riflescope uses a side focusparallax adjustment which, whenproperly set, eliminates parallaxerrors.Parallax is a phenomenon thatresults when the target imagedoes not quite fall on the sameoptical plane as the reticle withinthe scope. When the shooter’sAdjust the side parallax knobeye is not precisely centered inthe eyepiece, there can be apparent movement of the targetin relation to the reticle, which can cause a small shift in thepoint of aim. Parallax error is most problematic for precisionshooters using high magnification.To set the parallax:1. Be sure the reticle is correctly focused (see Reticle Focus).2. As accurately as possible, match the yardage number(distance you are shooting) on side focus parallax adjustmentknob to the indicator arrow on the scope body.3. Check the setting for accuracy by moving your head backand forth while looking through the scope. The setting iscorrect if there is no apparent movement between the reticleand target. If there is apparent movement, adjust the focusknob slightly until the movement is eliminated.4. When properly set, the target image should be sharp andcrisp.Customizable Rotational Stop (CRS)Vortex Viper PST riflescope elevation turrets incorporate theunique CRS rotation stop feature. After the rifle is sighted in,the design of the CRS allows a shooter to quickly and easilyreturn to an original zero point when using the elevation turretto dial-in temporary bullet drop corrections.The CRS feature is particularly useful when dialing largemulti-revolution elevation corrections. Without this feature,the shooter must pay very careful attention when dialing theselarge corrections. If the shooter loses track of the number ofrevolutions, the original zero point may become lost whenreturning the adjustment. Viper PST riflescopes equipped withthe CRS allow the elevation dial to be quickly spun back tooriginal zero without having to carefully count revolutions orclicks.Once the CRS shims are installed after sight-in, the elevationdial will stop turning shortly past the original zero point whenbeing returned (turning clockwise direction) from a temporaryelevation adjustment. The shooter can then turn the elevationknob a partial turn in a counter-clockwise direction until thezero reference and radius bar are correctly aligned—achievingthe original zero point.See CRS shim installation in theBore Sighting and Final RangeSight-in sections.CRS Shims6 7