TW = Twin Cities arsenal.
Den = Denver arsenal.
Not sure of the others, they might be commercial manufacture.
All US surplus 30 cal rifle ammo (30-06) manufactured before 1952 used corrosive primers, and there were a few lots after that were also.
Eleanor08 wrote:You know, every time I've been to Gunstop, I haven't seen any primers or powder. I'm not sure he keeps it in back or if hes just out of it.