Hmmm.....
On my M1S gun (M4 style stock)...the charging handle just barely scrapes the top of the receiver end plate.
This is because it is oversized. It is wider than the castle nut.
On my Colt (Colt M4 stock), the receiver end plate is the same diameter as the castle nut. They mate perfectly. This seems to be the proper specification as this allows staking to be done on that plate into the tiny recesses in the castle nut to prevent it from coming loose.
This would be really, really hard to do on the M1S because there is too much material to bend back and inward to make a stake. You'd have to do it not from the side of the plate, but from the face of it, which would also be extremely hard, if not impossible to do.
It doesn't hurt anything, but it does rub me wrong, as that is NOT how its suppose to be.
EDITED TO ADD:
Also...the M1S charging handle is less "beefy" than Colts. As a result it flexes more. This might cause some scraping during the rearward stroke of the charging if you press down hard like a barbarian. However, the scraping is happening during the forward stroke after you let go of it.
It has been noted in the past on this forum (and I've confirmed this personally by measuring) that the M1S charging handle is shorter on the face where the gas hole is. This *might* make the tolerance sloppier as to where it "grabs" onto the ledge on the bolt carrier. This can cause the CH to be just ever so slightly tipped more than would be a real charging handle. This, plus a taller receiver end plate has created a situation where the charging handle is scraping.