Specially designed for the Bradley Fighting Vehicle, the M231 Firing Port Weapon provides critical firepower to soldiers in combat.
Modified M16 Assault Rifle
The M231 Firing Port Weapon is essentially a modified M16 assault rifle. The weapon allows soldiers to shoot from two firing ports located at the rear of the Bradley Fighting Vehicle. The M231 was developed because regular sized M16 rifles are too long to be used effectively in a fully loaded Bradley Fighting Vehicle or Armored Personnel Carriers.
The U.S. military began developing a dedicated Firing Port Weapon in the early 1970s as they were moving forward with the "Mechanized Infantry Combat Vehicle." The plan was to develop a compact automatic weapon that soldiers could fire from inside an "Infantry Fighting Vehicle" such as the Bradley. Soldiers shoot the M231 out of firing ports located on the vehicles. There used to be firing ports on the sides and rear of the Bradley Fighting Vehicle. However, all of the firing ports have been removed except in the vehicle’s rear.
Unique in its Own Right
Although modeled on the M16 assault rifle, the M231 has several different specifications that make it a unique weapon. The M231 is only capable of fully automatic firing and is almost never used outside of the Bradley Fighting Vehicle. In total, the M231 and M16 share 65 per cent parts commonality.
The M231 was designed by both the Colt Manufacturing Company and Rock Island Arsenal. The weapon came into service in 1980 and was also modeled partly after the M3 submachine gun.