There also was an M3 carbine semi and full auto equipped with a bulky night vision sight. Very rare.
The M3 "Grease gun" replaced the Thompson Sub-machine gun.
M-14 replaced the M1 Garand. M-16 replaced the M-14. M1A is a semi-auto M-14 that civilians can buy.
AR-15 is semi-auto M-16 that civis can buy.
M1 Garand-the best ever full size battle rifle-cal. .30'06
M1 carbine-short and handy though some say underpowered-cal. .30 carbine
M2 carbine- semi and full auto carbine-cal .30 carbine
M3 carbine-equipped with big bulky night vision scope-cal. .30 carbine
M1 Thompson Sub-machine gun-semi and full auto-cal. .45 ACP (ACP=Automatic Colt Pistol used in 1911-1911A1 pistol)
M3 "Grease gun"-semi and full auto-replaced Thompson-cal. .45 ACP
M-14-full size battle rifle-replaced Garand-semi and full auto-cal. 7.62X51 (.308 Winchester nearly identical)
M1A-semi auto civilian version of M-14-cal. .308 Winchester
M-16-rifle and carbines-semi and full auto-replaced M-14-cal 5.56X45 (.223 Remington nearly identical)
A "machine gun" shoots full size rifle type ammo. or the awesome .50 BMG (BMG=Browning Machine Gun). The smaller Browning machine gun fires .30'06.
A "Sub-machine gun" fires pistol caliber ammo. Sub meaning less than a rifle.
An "assault rifle" fires intermediate cal. ammo. This is, bigger than pistol ammo but not full size battle rifle ammo. ex; 7.62X39 ammo used in AK-47s which could be called .308 short (?). Assault rifles are semi AND full auto. Civilians can't buy full auto anything without a very thorough background check, buying a "tax stamp", and a govt. "anytime search" to make sure the gun is properly stored.They are also very expensive to buy and feed (they shoot LOTS of ammo very fast) and must be kept in a real safe away from thieves.
The "assault rifles" you hear about in liberal propaganda (falsely called "network news") are NOT real assault rifles because they do not fire full auto. Citizens can't buy real Assault rifles without the above mentioned hassles. So, the term used to describe civilian owned intermediate caliber rifles is a blatant lie used by liberals to demonize any gun a civilian can buy. A rifle that holds more than 10 rd.s but is semi auto only is NOT an assault rifle.
M2 carbines (semi and full auto) were manufactured only by Winchester and Inland (a division of General Motors' Saginaw Steering Gear). Many M1 carbines were converted to M2s by govt. arsenals and many were converted back to semi auto only after the war (but not all of them).