Strange problem with windage

[bigbearbear]

I'm using a Mueller Speedshot 1-4x red dot scope with a Burris PEPR mount on my Windham Weaponry MPC AR-15. I've noticed that I have a strange problem with windage.

After zeroing the rifle, it would shoot the whole day without issues. The zero doesn't drift or shift. After taking the rifle home, cleaning it and coming back again maybe a few weeks later, the windage seems to have drifted to the right. I went to the range twice without checking zero again (we didn't shoot well with it, windage could've been off already but I didn't check) and today when I tried it, the windage have drifted quite a lot, about 2 inches to the right at 50 yards.

I did check the tightness of the based screws today after returning from the range, one of them was just a tad loose, my torque wrench tighten it very slightly before going click. The other base screw was fine. The screws on the scope ring were all tight too.

Could it be the base screw off by just a little bit but resulted in this strange windage issue I'm having?

Thanks.

P.S.: Perhaps I should invest in a better mount? Any recommendations?

[Fjold]

Is it a two screw or a four screw base?

[bigbearbear]

Is it a two screw or a four screw base?

The 2 screw type.

[Fjold]

A loose screw could give you windage issues but it should have to be worse than slightly not torqued.

[bigbearbear]

A loose screw could give you windage issues but it should have to be worse than slightly not torqued.

Thanks, I will try to figure out what might be causing this. What I'll do from now on, is to check the tightness of the screws after each range trip and see if the windage changes again. If it does, chances are that the scope itself has developed a problem.

[postal]

A loose screw could give you windage issues but it should have to be worse than slightly not torqued.

Tend to agree, but... if it was a tad loose, the bouncing around on the drive to/from the range is a possibility the scope shifted.

OTH... maybe he shot 0 wind, then in a 30mph wind and forgot to mention it.

Op, regardless of any and all scope base/ring/mount instructions, I *ALWAYS* use a dab of blue removable loktite on all screws to be sure they dont work loose.

[CSACANNONEER]

It could be that the electronic inards are loose and shifting around during transport.

[bigbearbear]

Op, regardless of any and all scope base/ring/mount instructions, I *ALWAYS* use a dab of blue removable loktite on all screws to be sure they dont work loose.

Thanks, if it continues to give me problem I will use some blue loktite on it.

I've not shot the gun after the last trip back from the range but I might do so this weekend as my wife's shotgun is being worked on by a gunsmith so we can't do trap shooting for a while.

[bigbearbear]

It could be that the electronic inards are loose and shifting around during transport.

The odd thing is, the zero did not shift after I adjusted and kept shooting (about 300 rounds or so). Wouldn't the recoil from the AR-15 (however little there is) shift the zero?

[CSACANNONEER]

The odd thing is, the zero did not shift after I adjusted and kept shooting (about 300 rounds or so). Wouldn't the recoil from the AR-15 (however little there is) shift the zero?

You would think so but, I still threw the thought out there as a possibility.