yeah, it was pretty tight when i closed the bolt. i'll have to check the shoulder more closely. i just popped a round in there out of curiosity after i couldn't get it to close on the go gauge, but i didn't think too much of it at the time. I know bolt actions are a different ball game, but you can absolutely chamber a .50 bmg round in an M2 that is set below minimum headspace. that's why i was always trained to trust the gauges and not take shortcuts. Guys lose fingers taking shortcuts.