I've been shooting ARs for some years now.
I have 2 Bushys(M4A3/xm15-20") and have
fired many thousands of rounds through both.

After all the FLAWLESS firing I have noticed
that the notch wall on the upper receiver which catches
the charging handle latch in place is starting to smooth out a little. I'm aware this happens after
charging the handle thousands of times and was
curious if this is something to worry about.

Has anybody operated an AR to the extent where
the notch is completely smoothed out and would
not hold the charging handle latch in place?

Am I just worrying about something that won't happen?

Free bump 'cuz I'd like to know how much wear the High Round Count folks have seen too.

Considering that the only time that I use the cocking hand is to lock the bolt back, I have burnt rifles up, and still not had a problem with the cocking handles.

Granted that some guys will use the cocking handle every magazine or cock the rifle using the handle(instead of the bolt catch), I guess that it is possible to wear one out.
But at less that $11 to buy a new one, I would just treat it as the firing pin retainer, and change it out when needed.

Also, I guess that I have lucked out, since it seems that a few people here have had theirs snap, which I have never had on one of my rifles.

I recently owned a upper that had a hole worn right through the side by the hook of the charging handle. The spring was way too strong, so cutting the spring in half stopped it but there was already a hole.