Rifle Scopes Your guidance is requested on this "shifting zero"

[boltstop]

I have an interesting problem with which I hope you guys can offer some guidance - I notice that when I am shooting at a series of targets that are "four up," if I shoot at all four targets without changing a scope setting or varying ammo, the center of the group will shift either left or right.

This has to be an "indian" problem (as opposed to an "arrow" problem), as this seems to happen with any scoped rifle I own. Could this be:

<ul style="list-style-type: disc">[*]Cheek weld?[*]Failure to keep the rifle level?[*]Some sort of oddball parallax problem?[*]Something else that's just escaping me?[/list]

Your guidance = appreciated.

 

[deadly0311]

Re: Your guidance is requested on this "shifting zero"

If you are moving right of left of center, its either your Natural Point of Aim is jacked or you are slapping the trigger.

 

[boltstop]

Re: Your guidance is requested on this "shifting zero"

My groups stay small - this is what makes me think it's some kind of an "eye" problem, or a failure to maintain a good cheek weld.

Is it safe to assume, if you're hitting say low and left on one target, you should hit low and left on all targets every time?

 

[njlohmann]

Re: Your guidance is requested on this "shifting zero"

sounds like a trigger control problem to me. make sure that you are pulling your trigger Straight back and not off to the side at all. also make sure that you are not gripping the gun harder as you pull the trigger.

 

[Mike Casselton]

Re: Your guidance is requested on this "shifting zero"

Shifting zero could be a parallax problem too

 

[bcpdshooter]

Re: Your guidance is requested on this "shifting zero"

Try not wrapping your thumb over the grip and let it relax on the side of the grip. Use your fingers to pull straight to the rear keeping the rifle snug in the shoulder. Be sure the only contact with the rifle with the trigger finger is on the trigger. Also this often is over looked but make sure your follow through is good staying on the cheek weld until the rifle finishes the recoil.
+1 for all previous post aswell

 

[SScott]

Re: Your guidance is requested on this "shifting zero"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mike Casselton</div><div class="ubbcode-body">Shifting zero could be a parallax problem too </div></div>
+1
Get your rifle settled in for the shot, then bob your head while looking at the target and reticle, if the reticle moves at all in relation to the target, you have a paralax problem.
As another experiment, try shooting your groups with the power turned down on your scope, on lower power parallax issues will show up less.
SScott

 

[boltstop]

Re: Your guidance is requested on this "shifting zero"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Sunnyside Scott</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mike Casselton</div><div class="ubbcode-body">Shifting zero could be a parallax problem too </div></div>
+1
Get your rifle settled in for the shot, then bob your head while looking at the target and reticle, if the reticle moves at all in relation to the target, you have a paralax problem.
As another experiment, try shooting your groups with the power turned down on your scope, on lower power parallax issues will show up less.
SScott </div></div>

Guys, I will employ all your suggestions. It could indeed be trigger control. One of the scopes I mounted is the nice 1.5-6x Konus with a bubble level (and the cool blue dot). The bubble level is pretty sensitive - After mounting it and observing this fact, I realized that I could be tilting my long-guns ever-so-slightly and not noticing. If I shoot this new combo better than other rifles, I may have to mount bubble-levels to everything.

 

[AMTeam4]

Re: Your guidance is requested on this "shifting zero"

I would double check my parallax then focus hard core on consistency. Regardless of shooting technique preference just do it the same every time.
When I notice I'm shooting squirrely I try to find another shooter to get behind the gun and see how his groups look. It has helped me determine whether it's me, a bad ammo lot, the gun, or just difficult conditions.
Also, try dry firing for an hour once a week. The significance of dry firing sessions can be extremely underestimated. Some guys even dry fire in the dark to work on just trigger control.

 

[AMTeam4]

Re: Your guidance is requested on this "shifting zero"

One more possibility I just thought of is to check your scope's ocular focus. When focusing the ocular lens of a rifle scope you are focusing the lens to the reticle. A good way to do this is to hold out a white piece of paper a foot away from your objective scope lens and then focus the reticle. Close your eyes for a few seconds and then look through your scope. If the reticle is clear and sharp then the ocular lens is properly focused.
An off focus ocular lens can cause the "floating zero effect." A tight group will be possible but every time you get back behind the rifle and your position is not exactly the same your zero will slightly float off target.