M4 carbine. U.S. Army Sig's family of MXC firearms — which includes the M7 — are also partly derived from the AR-15/M16, but ...

The M4/M4A1 5.56mm Carbine is a lightweight ... It is now the standard issue firearm for most units in the U.S. military. Equipped with a shorter barrel, collapsible stock and detachable carrying ...