Add the T29
- Yes
- No
The T29 Submachine Gun

T29 serial number X39. The T29 version of the M3A1 submachine gun, chambered for the .30 carbine cartridge. The T29 was conceived to provide the weapon with a longer effective range over the .45 ACP round. The magazine was fabricated from two 15-round carbine magazines. (SPRINGFIELD ARMORY NATIONAL HISTORIC SITE)
Inspired by the German MP43, during fall 1944, it appeared advisable to investigate the possibility of modifying the M3 submachine gun to permit the firing of the carbine cartridge caliber .30 M1. This investigation was entered into in view of the many reports received from the field requesting the development of the submachine gun which would fire the caliber .30 carbine round. Considerable study was given by personnel of the design section of the Guide Lamp Division of the General Motors Corporation that was manufacturing the M3 submachine gun.
To reconfigure the M3 submachine gun to accomplish the above, it was necessary to use a spring-loaded ejector to soften up ejection. To facilitate retracting the bolt, and still maintain the proper spring load to prevent the bolt from striking the rear receiver in recoil, it was necessary to employ both a shorter, stronger spring and a longer, low-rate spring; the short spring being required primarily to stop the bolt in recoil and the long spring to feed and fire the cartridge. A 30-round magazine was made by attaching two 15-round M1 carbine magazines together; the magazine well was enlarged to accept carbine magazines. A 14-inch long barrel was used to maximize velocity and reduce muzzle flash. The bolt was redesigned for the .30 carbine round.

T29 serial number X38 (top of image) and T29 serial number X39, two of the three T29s made in 1944. The T29 was basically an M3A1 submachine gun with an enlarged magazine well and a longer 14-inch barrel. The higher pressure generated by the .30 carbine cartridge required a new spring system to keep the bolt from striking the back of the thin sheet metal receiver. During World War II, the primary U.S. weapons were the semiautomatic M1 rifle, M1 carbine and the full-automatic, capable Thompson submachine gun. What was needed was a full-automatic weapon with a longer range. (SPRINGFIELD ARMORY NATIONAL HISTORIC SITE)
The .30 caliber T29 weapons were tested during the fall of 1944. The modified submachine guns incorporated the basic design characteristics of the M3A1 submachine gun were completed, and function fired 1500 rounds per weapon. There were many functioning problems encountered due to the more powerful cartridge. Despite the longer barrel, the report and flash were quite excessive. Further study of the T29 submachine gun showed the Type A spring-loaded ejector and the feed ramp would require further development. However, in that the select-fire caliber .30 M2 carbine was standardized in September 1944, it was not deemed advisable to continue further development work on the T29 submachine gun concept, and the T29 project was terminated on November 16, 1944.
I would love to see this gun added for the fallen M2 that should have been added as an assaulter weapon. The T29 would make a great AR for the allied who unlike Germany lack them. A 30 round 1500 BPM would make a strange AR. 30 caliber carbine is an excellent round that is only used in a few guns like M1 and M2 carbines. Given how little information is available a full auto, semi auto or burst mode could be added. a great event weapon as not to step on the german toes