Action: Semi Auto – Caliber: .45 ACP – Capacity: One each 50 Round Drum and 20 Round Stick Magazines – Finish: Hard Chrome Plated – Stock/Grip: Fixed Walnut – Sights: Blade/Adjustable – Barrel Length: 16.5 – Overall Length: 41 – Weight: 13 lbs. – All the classic details of the time honored original are reproduced in today’s semi-auto Thompson. The frame and receiver are machined from solid steel or aluminum. The wood is genuine American walnut. This .45 caliber carbine features a 16 1/2 finned barrel compensator and is available with a blued steel receiver or a lighter weight aluminum receiver. This configuration is our most popular model.