Rifle Scopes Is my scope possessed?

[obilly]

I recently purchased a vortex viper PST 6.5-24x50 SFP to remedy a problem I was having with a cheaper version of the same scope. Unfortunately I’m having the same problem with this scope so now I’m stumped please help me.

Just to clarify, my scope is on with the objective lens facing the target my elevation turret is up and my windage turret is to the right. All of my screws are tightened with a torque wrench to what the package suggests and held in place with blue Loctite. This happens on more than one rifle so I don’t suspect the weapon.

The problem is: I have noticeable windage adjustment when I move my elevation turret. The windage turret moves freely and easily when I correct for the change but when I move back down to my zero my POI reflects the windage adjustment and I miss on the opposite side. @ 500 I’m 1 mill high and .4 mills right. @ 100 I’m zeroed and—assuming I made an adjustment to score the hit @ 500—I’m .4 left. If I just go up and back down I don’t have any windage change at my zero.

Lastly, I have worked very hard to ensure my scope is plumb with my rifle by way of a vice, plumb line and level. Also, when I’m shooting I’m carful to maintain a level rifle.
I was advised to “optic center” my scope but I don’t have adjustable rings so that’s a no go.

All I have is a 20 moa, mill spec rail and Leopold rings.

I’m out of ideas.

 

[Nortex]

Are you sure it's not drift? I don't see how it would move when you adjust up then go back to normal when you go back down. If it was broke it would likely be doing screwy things the entire time. That and being you said anothet scope was having the same problem I would say your issue lies elsewhere.

 

[Captain Kirk]

Sounds like you need to perform a box test. You can actually see how your scope is tracking by rotating the turrets and watching the reticle, ensuring your rifle is stationary. If your reticle windage is moving when you make a elevation adjustment, you have a problem.

 

[270Win]

your scope isn't possessed its broke... probably a erector spring is broke

http://www.airgunsofarizona.com/blog/2010/04/how-scopes-really-work-and-what-not-to.html

http://www.opticstalk.com/what-makes-swarovski-better_topic19469.html

 

[Scott_at_Vortex]

What number is the rotation indicator at on your windage turret when it is zeroed? It sounds like the erector tube may be hitting the scope tube when you are dialing your elevation. This is caused when a good amount of windage has to be used to get the rifle zeroed. When there is certain amount of windage dialed(varies from scope to scope) it will limit and/or restrict the amount of usable elevation. In some instances the elevation may still adjust at the outer limits ,but if it is riding the side of the scope tube the erector will adjust at an angle(following the scope tube).

All that being said, this is just a guess at what may be happening with the limited information at hand.

The fact that the exact same thing has happened with two scopes on the same rifle also leads me to believe this is probably what is happening. The reason I say this is because the same rifle was used. Which means the two scopes erector tubes would be in very similar(if not the same) position in the scope when the rifle is zeroed.

Compensating for a rifles tolerance stacking(bore curvature,action to barrel fitment,mounting trueness,etc....) is the reason scopes have to be adjustable. When a rifle has tolerances that are more than what the scope's adjustment can overcome we run into issues like the one at hand.


If you want to give us a call and provide me a little more info I can more than likely diagnose the problem for sure.

Best Regards
Scott

 

[Pinecone]

What rifle?

Many reports of some rifles with the scope mount holes not centerline of the bore. If they are not too far off, they can be fixed. Chad at LRI just fixed someone else's rifle, if this is the problem.