The U.S. Army and & Marines are working round the clock to check the M4s and M16s for a big problem that can be a danger to soldiers and marines. The issue here is a malfunctioning fire selector switch that can cause the rifle to be fired without the trigger being pulled.

According to a report by Task & Purpose, the incident happened last March 29 at Fort Knox in Kentucky when a soldier’s M4 accidentally went off when it was being checked for problems. The fire selector switch was between semi and auto detents when it was tested and failed to fire. But when it was put back into its place the rifle fired. The M4 in question was part of the series of M4 rifles converted through the Product Improvement Program (PIP).

Military.com also reports of this incident, citing a safety message issued out by the U.S. Army Tank-automotive and Armaments Command (TACOM), "The operator pulled the trigger with the selector switch between the semi and auto detents (outside of detent). The weapon did not fire when the operator pulled the trigger and instead fired when the selector was moved further."

Photo: U.S. Army M4 and Magazines (U.S. Army photo by Sgt. 1st Class Jacob Boyer)

Task & Purpose also says in the same article that the TACOM has found that 6% of the 52,000 rifles tested has the problem and they are will be testing a total 903,000 rifles and they expect repairs of affected rifles would take 12 to 18 months. It also mentions that the U.S. Marine Corps has issued their own safety message to check M16A4 rifles and M4A1 and M4 carbines though there have been no reports of the same malfunction happening amongst the rifles in use in the Marine Corps and that they are taking precautions.

There are the additional actions for the PIP-converted rifles being taken by TACOM as well as an Action Drill in case the weapon does not fire. You can read these via Miltary.com report.

Top photo: M4 during live-fire training in Afghanistan in 2015 (U.S. Army photo by Capt. Charlie Emmons)