Quote Originally Posted by rcathey View Post
You think perhaps it’s a quality stamping? These barrels were selected to go on refurbished M1Cs because of tighter measurements or something like that.
It seems to be some overhaul program that hasn't been documented before. The Punch mark is most likely a proofing mark, stamped after it was proof fired. The A, we don't know, either an Armory stamp of some kind, or possibly even an individual inspector.