Pin, not a screw for ejector IIRC. Will have to wait till I get home to be sure and certain it's not a roll pin (don't think rolled pin tho).
Both of my MkIs have original early barrels but it wouldn't surprise me to see a WWII barrel as a post/during war arsenal refurb, then off to the public via DCM post war.
Lookin good tahunua. You're on an '03 roll I tell ya. Keep up the good work sir.
Youth rebels, age conserves; between them, they advance. The Marines will cease to win battles the moment either camp achieves ascendancy. – Robert Leckie, Helmet for my Pillow