'Nevertheless, as a short-range weapon it is quite adequate and thus, its caliber, is classed as a submachine gun.' However, these rifles had design issues, as the barrel length was halved to 10 inches (25 cm), which upset the ballistics, reducing its range and accuracy and leading to considerable muzzle flash and blast, meaning that a large flash suppressor had to be fitted.

2.1.1 Special Operations Peculiar Modificationįollowing the adoption of the M16 rifle, carbine variants were also adopted for close quarters operations, the first of which was the CAR-15 family of weapons, which served through the Vietnam War.

Since its adoption in 1994, the M4 has undergone over 90 modifications to improve the weapon's ergonomics and modularity, including the M4A1, which strengthened the barrel and removed the burst-fire option, and the SOPMOD, an accessory kit containing optical attachments and the underbarrel M203 grenade launcher. The M4 has been adopted by over 60 countries worldwide, and has been described as 'one of the defining firearms of the 21st century'. The M4 is extensively used by the United States Armed Forces and is largely replacing the M16 rifle in United States Army and United States Marine Corps (USMC) combat units as the primary infantry weapon and service rifle. It is essentially a lighter and shorter variant of the M16A2 assault rifle. It has a 14.5 in (370 mm) barrel and a telescoping stock.

The M4 Carbine is a 5.56×45mm NATO, air-cooled, gas-operated, direct impingement, magazine-fed, select fire carbine.

Gas-operated, rotating bolt, Stoner expanding gasģ0-round box magazine or other STANAG magazines.

Colt m4 cr serial number