Semi-automatic carbine version, featuring a 6.5 inch barrel with a 9.5 inch muzzle device permanently welded to it, which is actually a modified version of the baffle core of the integrally suppressed variant.
2.
The Bureau of Alcohol, Tobacco, Firearms, and Explosives ( BATFE ) made a regulatory determination in 2013 that the muzzle device of the SIG MPX Carbine, adapted from the baffle core of the integrally suppressed version's suppressor and claimed by SIG to be a muzzle brake, constituted a silencer and rendered the MPX-C a Title II NFA weapon.