Darn, forgot to put this in the original post. About the .30 carbine, it was designed to replace the pistol for truck drivers, tank crews, engineers, radio operators, machine gun crewmen, and other troops who needed a weapon but didn’t need a full sized rifle. Pistols are an extreme close range weapon for a battlefield soldier, are difficult to shoot accurately unless you have a lot of training and practice.
Plus pistols were still in somewhat short supply and there was some reserve capacity in the production lines that was not being used for rifles. Winchester produced the design that won the trials for the “light rifle”. It was designed to weigh half as much as the issue rifle and have an effective range of 300 yards. It was really more of a 100 to 200 yard weapon and was effective in its designed role. When used as a primary weapon, it didn’t fare as well. It’s reported failures to stop attackers began in the winters in the European theater and later in the Korean war against the heavy quilted uniforms of the Chinese.
It was superior to the weapons it replaced( the Thompson SMG (11 pounds empty) and the pistol) for line of support troops.