Bushnell Holo not straight on flattop

[pete10]

I have a Bushnell Holosight mounted directly to my A3 flattop upper. It is solid and zeroed, but it sits canted a little to the left. I intend to get a Larue QD mount for it, but until I do, does anyone have any ideas why it may not be mounting flat and flush? I tried to mount it a few times before zeroing, with the same results.

Thanks

[dzhitshard]

Have you,
changed rail locations?
removed the screw & checked the optics set @ that point?
removed the optic after a few mags & checked for worn spots on the optic & receiver rails?

The optic rails are soft & if it has a pressure point from not being set square in a spec receiver cut it will have wear marks.

[pete10]

Have you,
changed rail locations? Yes, no help.

removed the screw & checked the optics set @ that point? Yes, no discernible flaw or problem.

removed the optic after a few mags & checked for worn spots on the optic & receiver rails? No, but I will check that out. Thanks for the advice!

The optic rails are soft & if it has a pressure point from not being set square in a spec receiver cut it will have wear marks.

I ran it into the range, and had them play around with it. It seems that they have seen pic rails that were unevenly undercut before. We tried another Bushnell and an Eotech on a few flat tops and there were two others that they sat canted on.

Not a huge issue since it is parallax free, just a little anoying. I will be getting a Larue mount soon, I may try to even it up with the mount by filing the mount rail a little.

[ST911]

Which manufacturer?

[pete10]

Mine is a Bushmaster, the ones tried at the shop were Smith M&P. Different Holo there too.

[dzhitshard]

I ran it into the range, and had them play around with it. It seems that they have seen pic rails that were unevenly undercut before. We tried another Bushnell and an Eotech on a few flat tops and there were two others that they sat canted on.

Not a huge issue since it is parallax free, just a little anoying. I will be getting a Larue mount soon, I may try to even it up with the mount by filing the mount rail a little.

That's a terribly high percentage of unsat gear for such a small sample IMO.

I've had many rifles & several Eotechs & have only seen issues on the combo that have to do with operator head space issues. Granted my equipment has all been tier 1. I suppose it could happen more often with lessor quality gear.

IMO it is a big deal since it's more than parallax at stake.
First you have adjustments of elevation & windage that aren't metered square now.
Most importantly though the optic isn't sitting solid if it's not square. It's going to be difficult to maintain zero.
Just my opinion but I'd be looking into this pretty hard if it was mine.
Good luck

[pete10]

That's a terribly high percentage of unsat gear for such a small sample IMO.

I've had many rifles & several Eotechs & have only seen issues on the combo that have to do with operator head space issues. Granted my equipment has all been tier 1. I suppose it could happen more often with lessor quality gear.

IMO it is a big deal since it's more than parallax at stake.
First you have adjustments of elevation & windage that aren't metered square now.
Most importantly though the optic isn't sitting solid if it's not square. It's going to be difficult to maintain zero.
Just my opinion but I'd be looking into this pretty hard if it was mine.
Good luck

Thank you for the advice. I will look into it some more. Thank you a little less for the Tier 1 dig.

[dzhitshard]

LOL
It wasn't intended as a dig on your bushy.
It was an honest statement.
I hope you find the culprit on the issue & report it back.

[pete10]

Not bent out of shape in any way, just a little dig back. I really do appreciate the advice. I have it zeroed right now, so not too much trouble on the adjustments like you mentioned, but I could see how that would be a problem. I may be exaggerating the cant a little too. Definitely less than a degree counterclockwise from plumb, just barely noticeable.