Ian from Forgotten Weapons presents the Thomas SMG in .30 Carbine. The model he’s holding might look like a standard 1928 Thompson, but it has a different magazine. In 1939, the Winchester Company developed the .30 cartridge for the US government. They were looking for an intermediate power carbine that would be better than the 1911, which they could issue to military support personnel.
When the US military released a request for what would become the M1 Carbine in 1940, the Auto-Ordnance Corporation offered up a Thompson submachine gun simply rechambered for the new .30 Carbine cartridge. This entailed a new magazine, a receiver modified for the longer magazine, and a new barrel and bolt face — but the other Thompson parts could remain unchanged from the standard .45 ACP models. The idea was that the existing design could be re-manufactured without re-tooling everything. This made the submission a pretty cheap and easy effort for Auto-Ordnance, which is a good thing, considering that it was almost assured to be rejected.
Thompson was the standard-issue sub-machine gun at the time, and the company was worried that the .30 cartridges, which they didn’t make, would make their weapons obsolete. So Auto-Ordnance submitted a light gun design that was different to the Thompson, along with this design as a back-up plan.
The stipulations for the new carbine included a weigh requirement of 5 pounds, and the Thompson weighed more than double that (in both .45ACP and .30 Carbine forms). Only a few were made, and the one submitted for military testing was rejected outright on the basis of weight. The guns were never even fired in action. Ian takes a closer look at the gun, including its markings, and the magazine.
This example is serial number 1, and resides at the Cody Firearms Museum in Cody, Wyoming, where they have an extensive collection of old firearms.