The M1 Garand was the weapon of choice for infantry. The M1 Carbine, half the weight and with a less powerful cartridge, was the weapon of choice for support troops, and others not primarily involved in infantry combat. It was designed to meet combat needs less demanding than the M1 Rifle, but more than can be met by the M1911A1 pistol. It was more convenient to use than the M1, and less intrusive to their other duties, while still much more effective than hand guns.
Originally, the M1 was to be capable of selective fire control, but this was dropped. Because a demand arose for an automatic capability, the M2 was developed, with a selective-fire switch added to the left side of the receiver, operating on the sear mechanism.
The US Carbine, Caliber .30in, M3, or T3, was simply an M2 with suitable mountings prepared on the receiver to take various models of infra-red night-sighting devices. No open or conventional sights were provided, and the IR carbine mounted an M3 flash hider, a simpler design than that for the M1C Garand. The M3 carbine, (its development title was T3), was produced in limited numbers as a semi-prototype. Only about 2100 were manufactured compared to 5,510,000 M1 carbines, 150,000 M1A1 carbines and 570,000 M2 carbines.
The M1 and M2 Carbines were also much more powerful than the Russian type burp guns used by the North Koreans and, later, the Chinese, having more than twice their muzzle energy.
In the infantry, the M2 Carbine was carried by Staff NCOs and officers. With its 30 round magazine, rapid fire and greater stopping power, it was an effective counter to the various submachine guns used by the Communists in the Korean War.
In intense cold, however, such as the Chosin battle, light weapons such as the carbine and air-cooled .30 calibre light machine guns malfunctioned much more often than the M1 and the water-cooled heavies, with anti-freeze in their jackets. The Marines used alcohol based hair tonic as anti-freeze lubricants for all light weapons, with good success, but the carbine components were small and fragile, and repeatedly malfunctioned.
The Carbine continued to be used in Viet Nam, until replaced by the M16.
The following additional information is courtesy of:
R. E. Sullivan, Colonel, USMC ('43/'67) (Ret.), Sun, 28 Nov 1999
The most unattractive feature of the M-1 Carbine as we had them in WW II and up through at least part of 1948 was the leaf type sight. There was no windage adjustment at all, and I've fired record on the range with those things, on say target 20, but had to hold in the left side of the bull on target 18. Then in '48 we got a modification that put a ramp type sight for elevation and an actual movable peep for lateral movement. Now those were worth taking to the dance. One thing about bullets, impact, weight, muzzle velocity etc. that afficionados of weapons take so seriously: My experience, on many battlefields, is that if you get a head shot or a pentrating wound to the body cavity, it takes the spirit of the bayonet plumb out of the individual you're shooting at.
