Army infantry beginning adoption of upgraded M4A1 carbines


The Army has begun to roll out improved M4A1 carbines for general infantry. The M4A1 in an improved version of the M4 carbine that has been in limited service since 1994, largely with special forces.

The improvements over the M4, which was also introduced in 1994, are small changes, but they contribute greatly to the carbine’s reliability and accuracy. The introduction of the M4A1 follows on the heels of the cancelled Improved Carbine Competition, a trial to find a replacement for the M4.

“In Afghanistan, there are times when a soldier needs an automatic-capable carbine to put down suppressing fires while soldiers are conducting fire movement and the like,” Command Sgt. Major Doug Maddi told the Army Times. “They’ve asked for that … and we’re very pleased we’ll be able to field a weapon system that can offer more lethality when they’re in combat.”

These upgrades have ruled out the necessity of a new rifle platform, and all the associated costs, because they can be added to rifles already in service. While some units have already been fielded with M4A1 carbines, this marks the beginning of the upgrade program going into effect.

The 1st Infantry Division — the Big Red One — is the first unit to have its rifles upgraded to the M4A1 standard. The M4A1 has a heavy-profile barrel that has better heat absorption and dissipation properties and increased rigidity. Combined with a standard full-auto fire control group, not a three-round burst trigger, means better accuracy as well.

Burst triggers have different trigger pulls, depending on where the fire control group is set, when used in semi-automatic fire. This makes them unpredictable and unpredictable is the last thing a soldier needs when it comes to their rifle.

The heavy barrel is also better suited for the new M855AI EPR cartridge, which is faster and hotter than the ammo currently in regular use with M4 carbines. The Enhanced Performance Round operates at close to proof pressure and puts more stress on barrels, but it has much better terminal performance, accuracy and barrier penetration than ammo in common use with the military.

And recent years in Afghanistan and Iraq have proven that consistent, accurately-placed semi-automatic fire and in a pinch, sustained suppressing full-auto fire are more important than three-round bursts. In short, G.I.s have as much to benefit from the M4A1 as special forces.

The new carbines also feature a backup iron sight, a more modern rear sight than the carry handle-style sight standard to the M4. This allows soldiers to use the flattop for red dot scopes and other optics. Even with the changes the M4A1 only weighs 7.74 pounds, retaining its light weight and maneuverability.

Some non-special forces units have have been using the M4A1 since 2012, such as the 101st Airborne, but they have been issued the carbine as-new. This is the first unit to have their rifles upgraded to the new standard.

The upgrades cost about $240, a far cry from the cost of a new rifle, and the Army plans to upgrade some 500,000 rifles to M4A1 carbines by 2019. The total cost of the M4A1 upgrades is estimated to be about $120 million.

The first soldiers have begun receiving the upgraded M4 carbine, the M4A1 — the same weapon used for decades in special forces units.

The 1st Infantry Division at Fort Riley, Kansas, is the first to get the converted weapons, Army officials announced Wednesday. The new features of the deadlier weapon include a heavy barrel, ambidextrous fire control and a new fully-automatic drop-in trigger option to replace the M4’s “burst” setting. The barrel’s weight allows the weapon to better resist heat and cook-off, allowing a sustained rate of fire.

“Those piece-parts are part of conversion kits currently being applied at Fort Riley, and that increased capability not only includes an increased rate of fire, resistance to cook-off, but improved ergonomics,” said Product Manager for Individual Weapons Lt. Col. Shawn Lucas.

The Army is spending an estimated $120 million on the program, which amounts to roughly $240 per weapon, with plans to convert the Army’s inventory of 500,000 previously fielded M4 carbines through 2019.

Beyond the “Big Red One,” the 3rd Armored Brigade Combat Team, 3rd Infantry Division, at Fort Benning Georgia, is tentatively set to receive the upgrade in July, and the 4th Brigade, 3rd Infantry Division, of Fort Stewart, Georgia, is tentatively set to receive it in August. Lucas said brigade combat teams are getting the upgrades first, based on the priorities of Army headquarters, readiness cycles and unit buy-in.

The Anniston Army Depot in Alabama upgrades about 300 rifles every week. The finishing touch is a laser engraving. The carbines are marked M4A1 and the selector is blessed with the word “auto”.

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