Rifle Scopes Bushnell DMRii possible problem

[endlesscoffee]

Ok everyone first post, but I lurk and normally find any answers I need through the search. I have a question on a scope I've had that I can't seem to figure out if it's me or the scope. I've been having issues with the scope holding zero between range days and sometimes having to re check my zero mid range day. I feel like I've been wasting a lot of ammo chasing this issue. I notice that when I put the scope on the lowest magnification from 5 down to 3.5 it seems to push the glass forward so I can see the tube. I've placed a video at the bottom to show this a bit. Im not sure if I'm going nuts or just having some wretched range days.
I have an older 700XCR .308. Currently I'm shooting 168smk.

 

[supercorndogs]

The tunneling is normal in that scope if that is what you are referring to. Reduction in magnification with no increase in FOV. Most of the time when I have seen zero problems it wasn't the scope.

 

[Danattherock]

I would rule out mount/rings, base screw loose, loose action screw, and similar first. Also, if your fundamentals aren't solid, not suggesting that's the cause, just something to rule out. mounting rifle to different parts of your shoulder can cause POI shift very easily as the rifle bounces off you differently. Leaned they lesson the hard way myself.

 

[endlesscoffee]

The tunneling is normal in that scope if that is what you are referring to. Reduction in magnification with no increase in FOV. Most of the time when I have seen zero problems it wasn't the scope.

Ok awesome thanks. I've never had a scope do this so i was a little paranoid. I also had a batch of ammo that had a pretty bad SD so hoping that might have been it. Finally got a good amount of one lot number. Hopefully i can get to the range soon.

 

[endlesscoffee]

I would rule out mount/rings, base screw loose, loose action screw, and similar first. Also, if your fundamentals aren't solid, not suggesting that's the cause, just something to rule out. mounting rifle to different parts of your shoulder can cause POI shift very easily as the rifle bounces off you differently. Leaned they lesson the hard way myself.

This isn't my favorite or most comfortable rifle by any means, but with my old cheap bushnell I didnt have any issues. I'll be running the fixit stick through it tomorrow before I head out again just to be safe. I normally check the screws before I even fire a round.

 

[Danattherock]

Varying ammo or projectile lot numbers could cause some headaches for sure. I would be certain this variable was accounted for when speaking of a wandering zero. Could be applicable.

 

[TxWelder35]

X2 on making 100% sure nothing is loose