AJ
US Veteran
Thompson...and that is what those boxes are for TSMG. military mags held 20. And I'll bet they all fire just fine. Heck I even have FA primers for 45 auto and 30-06 from 30s and 40s. Gave some to a friend who loaded a box of each...with period powder. All went bang. Even gave him a rough box of 20 rounds of 230 gr FMJs.. Corrosive of course.
The military was using boxes like that in WWI. Before the Thompson was in the inventory. I have several of those boxes in my collection and the ammo is dated in the teens.