Combat prototype
M4 is an iconic American assault rifle that is based on M-16A2 and was originally designed for operating personnel and combat vehicle crews. But it was later used by the US Army as a single weapon for all special operations forces.
Colt has undergone a number of upgrades throughout its existence. The M-16 assault rifle was made for US Special Forces as early as the Vietnam War. M-16A2 had a shorter foregrip and barrel; the front sight was moved closer to the shooter, and the massive plastic buttstock was replaced with a telescopic one. As a result, the M-720 rifle was adopted by US army in 1994 as M-4 and is no longer in US military service.

