M1919 Browning machine gun

The M1919 Browning is a .30 caliber medium machine gun that was widely used during the 20th century, especially during World War II, the Korean War, and the Vietnam War. The M1919 saw service as a light infantry, coaxial, mounted, aircraft, and anti-aircraft machine gun by the U.S. and many other countries.

The M1919 was an air-cooled development of the standard US machine gun of World War I, the John M. Browning-designed water-cooled M1917. The emergence of general-purpose machine guns in the 1950s pushed the M1919 into secondary roles in many cases, especially after the arrival of the M60 in US Army service. The United States Navy also converted many to 7.62mm NATO, and designated them Mk 21 Mod 0; they were commonly used on river craft in the 1960s and 1970s in Vietnam. Many NATO countries also converted their examples to 7.62, and these remained in service well into the 1990s, as well as up to the present day in some countries.

A similar conversion of the M1917 also produced the larger M2 Machine Gun, using the same basic operating principles and layout but firing the much more powerful .50 caliber (12.7mm) ammunition. The M1919 is distinguished by its smaller size and the use of a holed jacket around the barrel used on most versions.



With assistance from firearms engineers at Fabrique Nationale de Herstal, Belgium, the Model 1919 was completely re-engineered into the .30 caliber M2 AN (Army-Navy) aircraft machine gun. The .30 in M2 AN Browning was widely adopted as both a fixed (offensive) and flexible (defensive) weapon on aircraft. Aircraft machine guns required light weight, firepower, and reliability, and achieving all three goals proved a difficult challenge, with the mandate for a closed bolt firing cycle to enable the gun to be safely and properly synchronized for fixed-mount, forward-aimed guns firing through a spinning propeller, a necessity on many single-engined fighter aircraft designs through to nearly the end of World War II. The receiver walls and operating components of the M2 were made thinner and lighter, and with air cooling provided by the speed of the aircraft, designers were able to reduce the barrel's weight and profile. As a result, the M2 weighed two-thirds that of the 1919A4, and the lightened mechanism gave it a rate of fire approaching 1,200 rpm (some variants could achieve 1,500 rpm), a necessity for engaging fast-moving aircraft. The M2's feed mechanism had to lift its own loaded belt out of the ammunition box and feed it into the gun, equivalent to a weight of 11 lb (5 kg). In Ordnance circles, the .30 M2 AN Browning had the reputation of being the most difficult-to-repair weapon in the entire US small arms inventory.

The M2 also appeared in a twin-mount version which paired two M2 guns with opposing feed chutes in one unit for operation by a single gunner, with a combined rate of fire of 2,400 rpm. All of the various .30 M2 models saw service in the early stages of World War II, but were phased out beginning in 1943, as hand-trained rifle-calibre defensive machine guns became obsolete for air warfare (the .50 in/12.7 mm M2 Browning and 20 mm Hispano HS.404 automatic cannon had replaced the .30 in as offensive air armament as well). The .30 in M2 aircraft gun was widely distributed to other US allies during and after World War II, and in British and Commonwealth service saw limited use as a vehicle-mounted anti-aircraft or anti-personnel machine gun.

Other calibers
The same basic weapon was also chambered for the British .303 round, and was used as a basic fighter aircraft gun in fighters such as the Supermarine Spitfire until the widespread introduction of the larger caliber Hispano-Suiza HS.404 cannon, and throughout the war in bombers. British night fighter Mosquitoes used quartets of .303 Brownings in the nose and Beaufighters used six in the wings, with both having four 20mm Hispano cannon in ventral fuselage mounts.

On Lend-Lease British aircraft provided to the Soviets
The .303 variant equipped the Hawker Hurricanes delivered to Soviet Air Forces, during World War II. Soviet airmen compared them to their own, rapid-firing (at up to 1,800 rounds/min) ShKAS machine gun in terms of reliability: "But they often failed due to dust," recalled pilot Nikolai G. Golodnikov. "We tackled the problem gluing percale on all the machine-gun holes, and when you opened fire, bullets went right through. The machine guns became reliable then. They were of low efficiency when fired from distances of 150-300m."