T1/T5 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. 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. T1-C the semi-auto "Commando" features parkerized metal and all wood stock rear grip and horizontal forend in a durable black finish.