M1918 Browning Automatic Rifle - Design Details and Accessories

Design Details and Accessories

The M1918 is a selective fire, air-cooled automatic rifle using a gas-operated long-stroke piston rod actuated by propellant gases bled through a vent in the barrel. The bolt is locked by a rising bolt lock. The gun fires from an open bolt. The spring-powered cartridge casing extractor is contained in the bolt and a fixed ejector is installed in the trigger group. The BAR is striker fired (the bolt carrier serves as the striker) and uses a trigger mechanism with a fire selector lever that enables operating in either semi-automatic or fully automatic firing modes. The selector lever is located on the left side of the receiver and is simultaneously the manual safety (selector lever in the "S" position – weapon is "safe", "F" – "Fire", "A" – "Automatic" fire). The "safe" setting blocks the trigger.

The weapon's barrel is screwed into the receiver and is not quickly detachable. The M1918 feeds using double-column 20-round box magazines, although 40-round magazines were also used in an anti-aircraft role; these were withdrawn from use in 1927. The M1918 has a cylindrical flash suppressor fitted to the muzzle end. The original BAR was equipped with a fixed wooden buttstock and closed-type adjustable iron sights, consisting of a forward post and a rear leaf sight with 100 to 1,500 yard range graduations.

As a heavy automatic rifle designed for support fire, the M1918 was not fitted with a bayonet mount and no bayonet was ever issued. Only one experimental bayonet fitting was ever made for the BAR by Winchester. This was a standard, M1917 bayonet fitted at the Winchester factory with a special muzzle ring. The bayonet was attached to a standard M1918 BAR by means of a special experimental flash hider assembly. This prototype bayonet/flash hider assembly came from the Winchester in-house factory museum in New Haven, Connecticut with a tag printed on one side Winchester Repeating Arms Co./New Haven Conn., and handwitten on the other side: Combined Flash Hider, Front Sight and Bayonet Mount for Browing Automatic Rifle Model 1918 with Bayonet and Scabbard and the date - September 7, 1918. There is no evidence whatsoever of military adoption nor a military stock number, name, or classification.