Smacking an ACOG after adjustment - is it really necessary?

[scoutfsu99]

Here is a thread from Arfcom. It shows where the manual says to give it a tap. It might be familiar to some in this thread

http://www.ar15.com/forums/t_3_18/56...ro.html&page=3

[Slippers]

The manual that came with my TA33 says:

To ensure a consistent zero, it is best to fire one shot off target, allowing the recoil to stabilize the adjustment mechanism after an adjustment has been made, and then fire a three shot group on target.

[bullitt5172]

Both work, we have always trained the military to smack the optic. I've always told guys to fire a round off target. Either one settles the prism and allows you to zero without flyers. You can smack it with a ball peen hammer and not hurt it ��

[Kain]

Have a TA01NSN, yeah not the USMC model, but I have noticed on a occasion when zeroing that if not tapped with some degree of authority that adjustments would not occur and you would end up in the situation where you are chasing zero if you are not careful or have the first round sitting way the hell away from the rest. Tapping the turrets or shooting a second group to verify that the first wasn't just wonky is my usual MO in that type of situation. I chalk it up to a quark of the gear. Not like everything else doesn't have its weird quarks.

[R0N]

Not always needed with the COG, but often enough that its worth it to make sure your stacked failed adjustments don't send the shooter on a wild goose chase.
I have witnessed failures of the optics to adjust.
My experience is based on RCOs acquired between 2005 and 2009.
It is possible that then new models were susceptible to the issue, and possibly with use the stickiness clears up, or that the design has been corrected, but I can say without a doubt that it was an issue.

When I got the ACOG instructors MTT back in late of 05, the instructor told us to smack the turrets to take the slack and backlash because if not the adjustment would not be applied till the first round was fired.

[4thPointOfContact]

I don't know about 'smacking' but I have no objection to a little turret tapping after making an adjustment. I'll use the polymer handle of the screwdriver or the back of my magazine to give a tap, but that's just about it. Fortunately, sighting in is pretty much a one-time process unless something is changed.

[sevenhelmet]

Interesting. The explanation makes sense, but the manual for my TA31F makes no mention of a centering tap/smack/shot. I might have to experiment with my ACOG the next time I am at the range.

[Savior 6]

This sounds like chem light batteries to me. I'm supprised to find that this is doctrine but kinda understand the settling effect.

[T2C]

I have seen SWAT personnel tap their EO-Tech's with a screwdriver handle after zeroing because of zero shift when they fire their weapons. It was not just a few of them, it was all of them. I was not aware it was an issue with the ACOG, but given the explanation F2S gave in post # 7 it makes sense.

[Eurodriver]

I have seen SWAT personnel tap their EO-Tech's with a screwdriver handle after zeroing because of zero shift when they fire their weapons. It was not just a few of them, it was all of them. I was not aware it was an issue with the ACOG, but given the explanation F2S gave in post # 7 it makes sense.

I don't know about 'smacking' but I have no objection to a little turret tapping after making an adjustment. I'll use the polymer handle of the screwdriver or the back of my magazine to give a tap, but that's just about it. Fortunately, sighting in is pretty much a one-time process unless something is changed.

This is much more than tapping with a screwdriver handle. Think 19 year old US Marine palm striking the side of his ACOG 2 or 3 times as if he were performing a MCMAP maneuver. Seeing this occur so frequently is what made me decide to buy an ACOG - they have shitty eye relief, but they're bulletproof.

Here is a thread from Arfcom. It shows where the manual says to give it a tap. It might be familiar to some in this thread

http://www.ar15.com/forums/t_3_18/56...ro.html&page=3

I am not ashamed to admit that's me. I just don't bring it all over here because I'd be banned pretty quickly on a forum like this