 Contrary to popular belief, and even what some books claim, in spite of both being designated "M1", the M1 Carbine was "not" a shorter version of the .30-06 M1 Garand, as is typical for most rifles and carbines, but a wholly different design firing a smaller, less-powerful cartridge.The "M1" designates each as the first model in the new US designation system, which no longer used the year of introduction, but a sequential series of numbers starting at "1"