Over 100,000 battle tested, upgraded M4A1 rifles produced for US Army.

The M4A1+ effort was designed to look for add-on components that will "seamlessly integrate with the current M4A1 Carbine ... without negatively impacting or affecting the performance or operation of the M4A1 weapon," a FedBizOpps document states, reported by National Interest.

U.S. Army Sgt. 1st Class Joseph Graves fires the M4A1 Carbine at a range during the Army Materiel Command’s Best Warrior Competition July 9-11, 2018, at Camp Atterbury, Indiana. (Picture source : DVIDS)

The US Army has now produced at least 117,000 battle-tested, upgraded M4A1 rifles engineered to more quickly identify, attack and destroy enemy targets with full auto-capability, consistent trigger-pull and a slightly heavier barrel, service officials said.

The service’s so-called M4 Product Improvement Program, or PIP, is a far-reaching initiative to upgrade the Army’s entire current inventory of M4 rifles into higher-tech, durable and more lethal M4A1 weapons, Army spokesman Pete Rowland, spokesman for PM Soldier Weapons, told Scout Warrior in an interview. “The heavier barrel is more durable and has greater capacity to maintain accuracy and zero while withstanding the heat produced by high volumes of fire. New and upgraded M4A1s will also receive ambidextrous fire control,” an Army statement said.

To date, the US Army has completed more than 117,000 M4A1 upgrades on the way to the eventual transformation of more than 480,000 M4 rifles. The service recently marked a milestone of having completed one-fourth of its intended upgrades to benefit Soldiers in combat.