I recently built a new upper for my main rifle using a CMT upper. The problem started when I mounted my Eotech on it. My Eotech is mounted on the LT mount.

On my old receiver I had taken that same mount off and on many times with no problems, but now after just a couple off and ons while getting the rifle set up, the anodizing has worn off where the ball detente snaps over the rail, and where the lever rubs.

I never saw anything like this on my old receiver (RRA I believe), and to make it worse, the aluminum underneath is much softer than it should be, so the detente has worn a ditch in the rail, and the lever has done the same thing.

All this after just a few off and ons.

Is this normal for CMT uppers? It can't be right, at this pace my Eotech will fall off in no time, and I just shot the thing for the first time today.