"An overgrown .22." as the American soldiers in WWII named it. Became popular with tank crews, paratroopers, and other
special purpose soldiers (such as engineers, radiomen,
mortar carriers, etc.) Was fully taken out of the U.S Military around the Vietnam War, and has now made its way to the hands of police forces all over the world. It is also being sold by various companies on the civilian market.
It fires a .30
Carbine round, and has a barrel length of 18 inches. From the beginning of the war to the end there were over 6 million produced by many companies, alot of which are familiar to us today:
IBM- Computer company (most likely converted to a war-time factory)
Winchester
General Motors
Underwood
Rock-Ola
Quality Hardware
Standard Products
Irwin-Pederson