Dfariswheel
New member
If I understand you correctly, you're talking about the small area of wear just behind the barrel extension, in the top of the receiver. This looks like a dent between the barrel and the receiver.
This is caused by the "nub" (which is the bolt locking lug), bumping the ledge of the receiver. This happens because the barrel extension doesn't mate perfectly with the cut in the top of the receiver, and the locking block will just catch the edge as it retracts. This makes the small dent on the receiver.
This is normal, and causes no harm.
This is caused by the "nub" (which is the bolt locking lug), bumping the ledge of the receiver. This happens because the barrel extension doesn't mate perfectly with the cut in the top of the receiver, and the locking block will just catch the edge as it retracts. This makes the small dent on the receiver.
This is normal, and causes no harm.