|Colt M4 carbine, current issue model with removable carrying handle, left side|
At the present time, the M4 carbine is used as a front-line weapon by US Army, Marine Corps and SOCOM operators in Iraq and Afghanistan. Combat experience with thos weapon resulted in update program, which will, as of now (mid-2010) following steps. First, Army wanted to install heavier barrel to allow more sustained firepower, combined with full-automatic mode of fire instead of 3-round burst, and ambidextrous safety/selector switch. Second stage will see improved rail adapter and a new, improved bolt carrier, and a possible third stage will include change of operating system (most probably, from direct gas to the gas piston).
|Colt M4 carbine, current issue model with removable carrying handle, right side|
At the present time, the Colt company still is the the prime M4 carbine manufacturer for US Armed forces, but many other companies build similar "milspec" weapons for other US and foreign customers, such as government and private security organizations, law enforcement etc. To name just few, M4-type carbines are manufactured by Bushmaster Firearms, Olympic Arms, THOR Global Defense Group and others.
|Colt M4 carbine, old version with fixed M16A2-style carrying handle and M203 grenade launcher|
The M4 carbine differs from the M16A2 rifle only by having a shorter barrel and a telescoped, 4-position buttstock. The M4A1 is a similar modification of the M16A3 rifle
|Colt M4 carbine, current issue model with Trijicon ACOG telescope sight installed over the integral Picatinny rail and M203 grenade launcher mounted onto the RIS forend.|
|Colt M4 carbine with Mk.18 CQBR upper receiver, fitted with Aimpoint red-dot sight and additional back-up iron sights (BUIS)|
|THOR Global Defense Group TR-15 carbine, manufactured along the lines of US GI M4, but fitted with a number of accessories such as AAC silencer, Vltor rail forend and buttstock, and Trijicon ACOG 4X optical sight|