m2 carbine
Development of the M1 Carbine, capable of both semi and full-automatic fire. Because there is no real functional difference between the M2 Carbine and an upgraded M1, media has settled on discerning the two using their (interchangeable) magazines. A Carbine depicted with the curved, extended 30-round magazine is designated the M2 Carbine, while a Carbine with the boxy 15-round magazine is the M1 Carbine.