M1: The M1 Carbine is a lightweight, semi-automatic rifle developed for U.S. troops in WWII as a handy, powerful-enough personal deesfense weapon for rear-echelon soldiers, offering more range than a pistol but less bulk than the M1 Garand. Chambered in .30 Carbine (7.62x33mm), it became popular for its ease of use and effectiveness, seeing widespread use in WWII, Korea, Vietnam, and by global forces, with modern reproductions still available. M2: The M2 Carbine is the selective-fire version of the popular M1 Carbine, adding a selector switch for full-automatic fire, widely used in the Korean and early Vietnam Wars, known for its light weight and .30 Carbine cartridge, bridging the gap between submachine guns and rifles, and notable for its curved 30-round magazines and effectiveness in close-quarters combat, though its relatively weak cartridge limited long-range efficacy.
Rough outline of an M1 and M2 carbine. They aren't much different because the M2 is just a modification.
