Magazine I.d. Needed

I found these in a box I’ve kicked around for years. No idea what they fit. Can you id and would anybody want them. Thanks

Looks like US M3 sub machine gun to me. They should have markings on the front side middle...manufacturer markings. Look through some gunsites for sales and you'll see what asking price is.

Agree, looks like M3 magazines - but some were not marked for the MAC weapons

Difficult to load by hand, need a loader or M3A1 stock hook, Thompson was a better magazine to load
and better feeding but now the TSMG is 100 years old ?

M3 grease gun mags have a notch on the side in the reinforced part . Mac mags don't 'cause the latch is on the rear of the pistol grip and catches the rear bottom of the reinforced section .
Chris

Reference the difference in M3 and Cobray/Ingram mags, read down a bit in this article. https://www.smallarmsreview.com/disp...darticles=1814