The Auto-Ordnance Thompson 1927A1 is a semi-automatic reproduction of the classic Thompson submachine gun with a 16.5-inch barrel to meet rifle legal classification. It retains the detachable buttstock, horizontal foregrip, and distinctive drum or stick magazine of the original and is chambered in .45 ACP. One of the most iconic American firearms in reproduction form. Type: Carbine Action: Semi-Automatic Caliber: .45 ACP Capacity: 20 Year introduced: 1975, USA Weight: 11.5 oz Overall length: 41" Status: Active Intended use: Historical Recreation, Collecting, Recreational