home Weapons Ballistic and artillery Serious Flaw Discovered in M4A1 Rifles

Serious Flaw Discovered in M4A1 Rifles

Oct 2, 2018

Photo US Air Force — 050323-F-9629D-056 Private First Class Michael Freise, 1st Battalion, 72nd Armor Regiment fires an M-4 rifle during a reflex firing exercise at Rodriguez Live Fire Complex, Republic of Korea on March 23, 2005. Soldiers from the 1-72nd supported 1st Squadron, 1st Calvary Regiment, deployed from Germany, during Reception, Staging, Onward movement, and Integration/Foal Eagle exercises (RSO&I/Foal Eagle). RSO&I is a complex multi-phase exercise conducted annually, tailored to train, test, and demonstrate United States and Republic of Korea (ROK) Force projection and deployment capabilities. Foal Eagle exercise runs simultaneously and trains in all aspects of Combined Forces Command's mission. (U.S. Air Force Photo By: Staff Sgt. Suzanne M. Day)(Released) 050323-F-9629D-056 A shell casing flies out with a trail of smoke as U.S. Army Pfc. Michael Freise fires an M-4 rifle during a reflex firing exercise at the Rodriguez Live Fire Complex, Republic of Korea, on March 23, 2005. Freise is attached to the 1st Battalion, 72nd Armor Regiment, which is taking part in exercises Reception, Staging, Onward movement, and Integration/Foal Eagle. The annual, multi-phase exercise is tailored to train, test, and demonstrate U.S. and Republic of Korea force projection and deployment capabilities. DoD photo by Staff Sgt. Suzanne M. Day, U.S. Air Force. (Released)

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The U.S. Army is fixing a flaw in its carbines that allows some of the rifles to fire without pulling the trigger, a serious and deadly defect. The problem is particularly common among rifles designed to fire fully automatic. The previously undiagnosed, unintended problem has been affecting some of the military’s M4 carbines.

It was found that some M4s would fire when charged and the selector switch was positioned between safe and fire. According to the Army Tank-automotive and Armaments Command (TACOM) message, “The M4A1 was charged and the weapon’s selector was positioned between ‘semi’ and ‘auto.’ When the weapon’s trigger was pulled, the weapon did not fire. When the selector was then moved into either ’semi’ or ’auto,’ the weapon fired without a trigger pull.”

Later the Command asked also to check M16 service rifles.

The average failure rate was about 6 percent of the M4A1 weapons inspected. “The problem is fixed by modifying the selector to remove the tolerance issue and the fault. TACOM is working on an Army-wide directive to repair weapons with the issue that will be released when it is approved at the appropriate levels.”

The problem is not with the individual components. Instead, it exists only when certain components in a small percentage, 6 percent to 9 percent, of the weapons, stick. Those components are being modified to eliminate the stoppage, which engineers believe has caused the potentially unintended discharge, as reported by armytimes.com.

The M4A1 Carbine is a shortened version of the M16A2 assault rifle manufactured by Colt. The M4A1 is a favorite amongst US Special Operations Forces.

The M4A1 variant comes with a safe / semi-auto / automatic trigger groups as opposed to the safe / semi-auto / 3-round burst configuration found on standard M4s, according to americanspecialops.com.