Carbines

Since SMGs are generally designed to fire low-velocity 9mm or .45" calibre pistol rounds, there are limits to their performance, particularly with respect to armour penetration. If someone requires a weapon with greater effective range or penetration, there is an alternative: the carbine. A carbine is distinguished from an SMG primarily by its use of a rifle cartridge (it is basically a rifle with a shortened barrel), and there can also be differences in operating mechanism. The principal SMG attributes of low cost, good short-range firepower, and midrange accuracy are valuable, but against a target wearing body armour, a carbine provides many of the same attributes while also providing the benefits of the high-velocity rifle cartridge.