M4A1

A gas-operated, magazine-fed carbine derived from the M16 rifle, adopted as the standard individual weapon of the U.S. Army and Marine Corps. The M4A1 variant features a full-auto fire-control group and heavier barrel profile in place of the original three-round-burst M4.

Effective range

500 m

💲 Approximate U.S. military unit procurement cost

Full specifications

Performance

Speed, range, altitude and engagement capability.

Effective range Distance at which the weapon reliably hits point targets. Higher extends engagement envelope.: 500 m

25th pct in class
Rate of fire Rounds per minute (cyclic). Higher increases suppression and hit probability.: 950 rpm

88th pct in class
Muzzle velocity Projectile speed leaving the barrel. Higher means flatter trajectory and better armor penetration.: 884 m/s

50th pct in class

Firepower

Armament, payload and guidance.

Main armament Primary weapon: main gun, cannon or missile type.: 5.56×45 mm NATO
Caliber Bore diameter of the main gun or rifle. Larger throws heavier projectiles; not simply better — ammunition commonality matters.: 5.6 mm
Ammunition Rounds carried (main gun) or standard magazine capacity.: 30

38th pct in class

Physical

Dimensions, weight and crew.

Length Overall length including gun/probe where applicable.: 0.84 m
Empty weight Weight without fuel, ammunition or crew.: 3 kg
Crew Personnel required to operate. Fewer reduces exposure; autoloaders trade a loader for mechanical complexity.: 1
Barrel length Barrel length — longer improves muzzle velocity and accuracy, shorter improves handling.: 370 mm

Program

Cost, production scale and operators.

Unit cost Approximate flyaway/unit cost where public. Defense pricing varies hugely by contract, offsets and configuration. Lower is cheaper.: $1,100

60th pct in class
Units built Total production run. Higher means proven manufacturing, mature logistics and spares availability.: 2,000,000

75th pct in class
Operator countries Number of countries operating the system. More operators means broader support ecosystem.: 60

75th pct in class

Specifications compiled from public Colt and reference sources ↗. Published defense figures are approximations — treat comparisons as directional. Last verified 2026-07-01.