Don’t really feel like writing a long, drawn out post, so here are the facts:
-Sighted in Aimpoint (mounted in a LaRue LT-150) last week
-Removed mount from upper and put it back on, making sure to push forward on the mount while doing so
-Noticed a change in zero; Aimpoint dot no longer on top of front sight post, where it was after it was dialed in last week
-Removed mount to look at the rail and noticed the some anodization missing
-Readjusted Aimpoint to place dot on top of front sight post again
My main concern is the fact that the throw lever is now contacting the upper receiver on bare aluminum and not the anodization. Before I forget, the upper is a Stag 2H with a “keyhole” forge mark. Will I run into any issues down the line? Or is it good to go despite the missing anodization? I just want to make sure whether or not it’s normal and also if any return-to-zero problems will arise down the line as the aluminum wears.
Thanks in advance for any help!
Missing anodization (notice the other marks on the anodization, which are perfectly normal and were put there when deciding where to place the Aimpoint):
Where the lever is when it makes first contact with the rail, about 45 degrees:
You are putting a steel part nice and snug to an aluminum part. The steel part will slightly mar the aluminum part. That just the way it is. Steel is MUCH harder and stronger than aluminum, which is why you want to use it for things like barrels, bolts, locking levers on scope mounts, etc.
There shouldn’t be a change in zero if it’s snug on the rail and it’s to the same position.
Week to week, people can have differnent zeros: clothing, shooting style/position, how hard you grip the gun, how tight it is in the shoulder, different ammo, etc. etc. etc.
Better test: During the same shooting session, fire a 10 round group. Do it as accurate as possible. Remove optic/mount from receiver, re-install. Fire another 10 round group to confirm zero.
If you want best/most consistent groups, fire slowly so the POI doesn’t change signficantly due to the barrel heating up.
Update? Curious about this as I have a LT mount on my ACOG that I plan on putting on my rifle and want to know if this is a common, mechanical, or user error.
Did your zero actually wander or did you just move the dot because it didn’t look the same? I only ask because my eyes play tricks on me all the time, so I check my zero a bit more frequently than I used to. I don’t move anything on the sight until the target confirms a change in zero, regardless of my perception.
There could be several reasons for your optic to lose zero. One thought is that your Aimpoint is bad (yes it does happen once in awhile). Second thought is that you have built a trench into your receiver by opening and closing it with the lever over adjusted (meaning too tight).
The wear appears to be excessive to me and am wondering if the anodizing is the correct type.
I just looked at my RAS M5 rail and yeah, the wear from my LaRue mounts on it look like a Nike “Swoosh” kinda and are not palpable with a thumb or fingernail. THey are just shiny check-marks kinda. The mark on yours looks really rough.
I’m pretty sure the optic is functioning as it should because I put a couple hundred rounds through the gun at my last range session and there was no change in zero.
As far as having the lever adjusted incorrectly, what is depicted in photograph is where the lever makes first contact with the rail, per LaRue’s instructions. The “shiny” marks forward of the area that is missing anodization are from the same mount adjusted to the same position.
The “shiny” marks seen in the pics can’t be felt at all, but the area in question is definitely palpable with a fingernail.
I sent an e-mail to LaRue last week to see what their take on it was, but haven’t heard back.
In any case, what’s the next step from here? Leave it alone? Contact Stag and see what they have to say about it? Please advise, and thanks for all of the help so far!
