Zero and remounted optics

[Mark/MO]

Last week I went to the range to sight-in a BUIS I recently added to my mid-length BCM AR. I removed my Trijicon scope, which is mounted in a Larue mount, and proceeded to zero the iron sight at 100 yards. Satisfied, I reattached the scope and fired 3 shots. My POI was basically unchanged. To be truthful I was surprised. Anyway I became curious so I fired 3 rounds from my M&P-15, removed the Aimpoint along with it’s American Defense mount, fired a few shots and reattached the optic. Again, no discernible change in point of impact.

Granted all shots were at 100 yards, not 200 or 300 but I was still sort of surprised. I’ve heard others claim such feats but I’ve heard others tout the wonders of the Sham-wow or whatever too. I saw a post last month from Ventura regarding problems he had with retaining zero after removing and reattaching a scope. I’m just curious if other’s experiences are similar to mine or am I just lucky?

[Belmont31R]

I regularly take off, and re-attach optics during transport, cleaning, etc. Never noticed any change in POI from one range to the next. Just one of the reasons why LaRue (and some others) are worth the money they charge for their product.

[Kchen986]

Same here. Have my ACOG in an ARMS # 19 mount, and usually take it off for cleaning (Avoid getting oil & solvents on the lens). Last time I took it out, first shot w/ the ACOG at 100 yards was in the bulls-eye. Repeatable zero is really nice. :D

That said, some knowledgeable folk here have stated that repeated removal will eventually cause slight POI shifts at further distances.

[dmanflynn]

Vince here with the shamwow!!!:D On a more serious note, my aimpoint in its larue mount had no noticeable change in POI either, after I remembered which slot I had it on:p

[JSantoro]

Despite the fact that this is what the MIL-STD-1913 rail was specifically designed to do, there are still whole regiments worth of individuals who refuse to believe that they hold zero with a proper, consistent mounting procedure. Usually, it's because they didn't do a re-mount consistent with initial mounting, so, of course, it's a problem with the system and not the man. Of course.

If your optic is on a quality mount, it will retain zero if you re-mount it on the same gun, in the same spot, in the same way you initially mounted it. Period. Even if there is a shift, I have yet to see it be more than .5MOA, and that's both rare and generally operator error when it does happen, or a problem independent of the rail.

Even if the individual isn't a Luddite, knowing something in your head is worlds different than seeing it work and knowing it in your gut. Glad you got some proof-of-concept experience.

We've come a long way since arquebuses, huh?