Colt M4 Carbine

Model	M4	M4 Commando
Caliber	5.56-mm
Cartridge type	5.56 x 45 mm
Dimensions and weight
Total weight	3.15 kg	3.08 kg
Total weight (with empty magazine)	2.52 kg	?
Overall length	838 mm	758 mm
Length (with folded buttstock)	757 mm	676 mm
Barrel length	370 mm	290 mm
Fire characteristics
Bullet initial speed	841 m/s	800 m/s
Rate of fire	700 - 940 rpm	700 - 940 rpm
Practical rate of fire	30 - 100 rpm	30 - 100 rpm
Magazine capacity	30 rounds	30 rounds
Sighting range	600 m	400 m
Range of effective fire	360 m	250 - 300 m

The Colt M4 carbine entered service with US Army in 1994. Basically it is a shortened M16A2 automatic rifle with a telescopic buttstock. This carbine was intended as a substitute for submachine guns. It is used by airborne troops, special forces, tank crews, vehicle drivers etc.

It's internal design is similar to the M16A2 with an 80% parts commonality. Although it has 140 mm shorter barrel and a telescopic buttstock. Carbine features an improved muzzle brake due to the short barrel.

Carbine executes single fire and three round burst.

Carbine is completed with dioptric sight, however an optical sight can be fitted. Basically all the accessories used on the M16 automatic rifle (such as a modified M203 underbarrell grenade launcher, laser pointers, sound suppressors, tactical lights) are compatible with the M4 as well.

There is also an M4A1 version SOPMOD version of the Colt M4A1 carbine with a modified M203 underbarrel grenade launcher of the M4. The M4A1 has a full automatic fire option instead of the three round burst. In other terms it is a shortened version of the M16A3. Sometimes the M4A1 is found with a heavier barrel to cope with overheating caused by an automatic fire.

Even more compact version of the M4 is the M4 Commando carbine, which is similar to the M4 except even shorter barrel.

A SOPMOD version of the M4A1 carbine fitted with accessory rails under and over the foregrip and in stead of the carrying handle. This carbine is optimized for special forces and is compatible with a great variety of special accessories.