Thompson M1A1 submachine gun
Manufactured by Auto-Ordnance Corp. c.WW2 for the US Army - serial number 432620.
.45ACP 20-round detachable stick magazine, blowback fully automatic, parkerized finish.
The M1 series of Tommy guns, made for the US military, differ from the previous 1921 and 1928 ‘overstamped’ models by having an horizontal front grip - a feature shared by the earlier military M1928A1 - a rougher finish, a non-finned barrel and more importantly a bolt actuator situated on the right of the receiver, no longer on top of it. They also couldn’t accept the 50 and 100 round drum magazines that make the Thompson submachine gun iconic to this day.
A Thompson M1921 with a 100-round drum magazine. Note the blued finish - earlier models were much fancier than military one.
These front pistol grips make me fucking cringe everytime I lay eyes on them.