Present to you my envelope of games CoD: MW2-M4a1 M4a1 (Carbine, 5.56 mm: M4) is a machine built in the United States on the basis of the M16A2 initially for arming the crews of military vehicles and equipment.
Despite this, United States special operations command (US SOCOM) has taken this machine as a single for all u.s. special operations forces. It currently goes and the whole army of the United States, because the greater convenience of shorter connector nowadays, when most of the army is mechanized infantry combat vehicle crews, and supporting troops, more than enough to compensate for a slight decrease of its characteristics in comparison with a rifle.