So . . . I have an AR15 flat top, and my primary sight is an Eotech 512 mounted on it. I'm very happy with it: it is easily zeroed without any particular effort on my part.

But I recently purchased a Burris AR-P.E.P.R. scope mount/rings for it so that I could mount a scope on it (duh . . .).

I love the Burris, it holds my scope well and it fits tightly on my AR. The problem is that the windage of the assembly is way, way off, so I need to use almost all (or all?) of my scope's internal adjustments to bring the rifle to zero.

Is there a way to adjust the mount such that I can move my scope's internal windage adjustment towards its midpoint?

Thanks.

(Cross posted here and at Optics)

You might be able to put a shim along one side.

When you sighted in the EOTech, did you have to crank it a bunch to one side???

If not, then I think either the scope or the mount is not right.

Hi BL O'Connor,
I'd be very intersted in your assessment of the Burris AR P.E.P.R mount. I tried on on an AR flat top a couple of days ago and all seemed well till I took it off then put it back on again. It all went to rat shit. Couldn't get the gun back on zero and it wandered all over the place. I need to get it back on the range to double check the scope (Nikon Monarch III) to make sure it's not that. What's your verdict?
Cheers

quote:

Originally posted by N E 450 No2:
When you sighted in the EOTech, did you have to crank it a bunch to one side???

If not, then I think either the scope or the mount is not right.

No . . . but what a great question. I just slapped it on, made some minor adjustments, and it was good to go.

quote:

Originally posted by Haggis:
Hi BL O'Connor,
I'd be very intersted in your assessment of the Burris AR P.E.P.R mount. I tried on on an AR flat top a couple of days ago and all seemed well till I took it off then put it back on again. It all went to rat shit. Couldn't get the gun back on zero and it wandered all over the place. I need to get it back on the range to double check the scope (Nikon Monarch III) to make sure it's not that. What's your verdict?
Cheers

I'll be going out tomorrow, and I'll let you know what I find. I have an idea that might or might not work.

For all who've responded . . . thanks for your input. I'd prefer to stay away from shims . . . they're just another thing to lose. But I may need to use them.

So . . . I tried my Great Idea out today, and it made no difference . . . The Great Idea was that if I moved the mount forward 2 - 3 slots, it might change the zero . . . but it made no difference whatsoever.

The good news is my scope is zeroed, and the rifle is a shooter . . . 8 rounds in <1 inch at 100 yards, with an additional 2 "thrown" to open the group up to about 2". (I'm not the world's best shot . . .)

I've thought through the shim solution, and think I'll just live with the scope maxed out, or close to it. I swap between my EOTech and scope often enough that I'm afraid I'd lose the shim at some critical point.

Haggis, I like my P.E.P.R. a lot. I had a problem with scattered shots, too, until I realized that the levers of the quick-release clamps must be adjusted for proper tightness. Initially, I had mine adjusted too loosely, and the scope wiggled very, very slightly . . . that doesn't help with accuracy.

Once I realized you had to adjust the clamps by turning the little nuts on the right side of the mount, one opposite each lever, I was able to establish a stable mount. (You do this by unlocking the levers, and then pushing them towards the right side of the mount against a spring. This releases the little nut from it's indexed position, which can then be turned - clockwise to tighten, counterclockwise to loosen. It's a trial and error sort of thing.)

If you've tried that and it doesn't work, I'd send it back to Burris and ask them WTF???

Hi BL,
Yes, I did much the same as you did.
Took the mounts off and re-adjusted them so that they were a tight fit.
Tested the AR again today and found tight 55gr groups at around 1". 62grain fodder opened out to around 4" and home loaded 70 grain fmj was around 7". This was all at 100 yards.
Bit of a dissapointment on the heavier stuff as the barrel was sold to me as 1 in 7.7. Kind of think I got bull-shitted. I need to measure the twist and maybe have a word with the supplier.
On the Burris front, very nice even if they're made in china!