Commercial Thompson with Cutts compensator, top-mounted actuator, and drum magazine capability. Used by US military, FBI, and Lend-Lease to Britain, USSR, and China. Type: Submachine Gun Action: Blowback Caliber: .45 ACP Capacity: 20 Year introduced: 1928, USA Weight: 128 oz Overall length: 33" Status: Discontinued Military use: Yes Intended use: military