The M1917 Browning machine gun is a heavy machine gun used by the United States armed forces in World War I, World War II, the Korean War, and the Vietnam War; it has also been used by other nations. It was a crew-served, belt-fed, water-cooled machine gun that served alongside the much lighter air-cooled Browning M1919. It was used at the battalion level, and often mounted on vehicles (such as a jeep). There were two main iterations: the M1917, which was used in World War I and the M1917A1, which was used thereafter. The M1917, which was used on some aircraft as well as in a ground role, had a cyclic rate of 450 rounds per minute. The M1917A1 had a cyclic rate of 450 to 600 rounds per minute.

Design and development

thumb|left|US Army 2nd Lt. [[Valmore A. Browning test firing a Browning machine gun. This gun was used in the Argonne Sector.]]

In 1900, John Moses Browning filed a patent for a recoil-powered automatic gun. Browning did not work on the gun again until 1910, when he built a water-cooled prototype of the 1900 design. Although the gun worked well, Browning improved the design slightly. Browning replaced side ejection with bottom ejection, added a buffer for smoother operation, replaced the hammer with a two-piece firing pin, and made some other minor improvements. With M1 ball, the M1917 had a maximum range of about ; with M2 ammunition, about . The U.S. equipped about a third of the divisions sent to France; the others were equipped equally with Hotchkiss machine guns bought from the French or the British Vickers machine guns built by Colt in the US. Where the Model 1917 did see action, its rate of fire and reliability were highly effective. The M1917 weapon system was inferior to the Vickers and Hotchkiss guns in indirect fire applications because the British and French cartridges had about 50 percent longer range than the M1906 cartridge, the .30-06 service cartridge used in World War I. (This was because of the inefficient aerodynamics of the M1906 cartridge's bullet, later fixed in the bullet of the M1 ball cartridge.)

thumb|left|A U.S. Marine firing Browning M1917A1 machine gun during the [[Battle of Iwo Jima]]

The Model 1917A1 was again used in the Second World War, and was primarily used with the M2 ball, tracer, and armor-piercing ammunition introduced just prior to the outbreak of hostilities. Some were supplied to the UK for use by the Home Guard since all production of the .303 Vickers was needed to resupply the equipment abandoned during the Fall of France. The M1917's weight and bulk meant that it was generally employed as a fixed defense or as a battalion or regimental support weapon. In this latter role, the disassembled weapon was carried by machine gun squads advancing on foot, which could rapidly deploy it to support the infantry in offensive operations. At the battle of Momote Airstrip in the Admiralties, the US Army's 5th Cavalry machine gunners killed several hundred Japanese in one night using their M1917 Brownings; one gun was left in position after the battle as a memorial to the desperate struggle.

thumb|upright|A Browning M1917 in action during the [[Korean War.]]

The Model 1917 was called to service again in the Korean War. On at least one occasion, U.S. soldiers in the Korean War urinated on the gun when water-cooling had failed in the frigid temperatures of the Korean winter. The Model 1917 was slowly phased out of military service in the late-1960s in favor of the much lighter M60 machine gun chambered in the new 7.62 mm NATO cartridge.

Many of the 1917s were given to South Vietnam. The last ones in regular US service were on the machine gun infiltration course at Fort Benning, Georgia, where their sustained-fire capability was an advantage in long nights of shooting over the heads of low-crawling trainees. The gun did continue to see service in some Third World armies well into the latter half of the 20th century. Some are still in use today by irregular military forces because the water cooled barrel allows for long periods of sustained fire.

M1917 and M1917A1 ammunition chests

The machine gun used a wooden ammunition chest that carried 250 rounds. The early M1917 model had an angled corner and a leather strap handle on top. The later M1917A1 model had a square corner and a cloth strap handle on top.

The wooden ammunition belt chest was replaced during WWII by the expendable metal box ammunition M1 adopted 6 May 1942. On 20 June 1945, a modified version known as the M1A1 was adopted. The M1A1 had a spring-loaded catch to fasten it to the M1917A1 tripod more securely and provide a better watertight seal. In the late-1940s the M19 box replaced the earlier metal M1 and M1A1 boxes, and a modified version known as the M19A1 appeared in the early-1950s and continues in use today.

Variants

US military variants

M1917

The original gun suffered from a weakness related to the design of the receiver. Under field conditions, the bottom plates, which were dovetailed into the gun's two side plates, tore out. An early fix was to attach a roughly horseshoe-shaped steel bracket around the rearmost part of the receiver. A later fix was to rivet "stirrups" (right-angled steel pieces) to the bottom and side plates. The stirrup fix became the standard reinforcement until a more permanent fix for the problem was developed. Another reported problem was bulging in the side plates, which was probably caused by stresses put into the side plates when hammering the dovetails closed. The 1917 also had a simple sliding safety that blocked the trigger when moved to the far right position. These were removed as part of post-war refurbishment.

M1917A1

thumb|left|M1917A1 with spare barrel and other issued accessories

thumb|right|An M1917A1 on tripod mount

In the 1930s, the Ordnance Department developed a new bottom plate, which had side flanges that came up on both sides of the receiver and were attached by rivets. This fixed the problem of the original bottom plates, and became standard for all M1917- and M1919-series machine guns. While the US Arsenal at Rock Island was the leader in converting the existing stocks of M1917-series guns over to 1917A1 configuration, other arsenals took part. In addition, the rear sights were updated for the new ammunition and were changed to yards from meters, and also did away with the World War I multiple-aperture disk on the rear sight. The top covers also had a stronger feed pawl pivot arm installed, so the gun could handle the stress of pulling an ammunition belt from the ground. Rock Island Arsenal also developed an all-steel water jacket that went into production around 1943; this was stronger than the earlier brass-capped jackets. These steel components were interchangeable with the earlier brass ones to allow for repair of worn or damaged water jacket components.

Other changes were implemented, some during the war, but not all M1917s received these updates. Beginning in 1938, the pivot in the top cover was replaced with a new one that would become standard on all M1919-series guns. While the World War I–pattern top cover hinge pin appears to have been retained on most converted M1917s, the later-production M1917A1s had a positive locking top cover hinge pin that allowed the top cover to remain open, lessening the chance of it dropping closed on one's hands while working on the gun—this became the standard on all M1919-series guns.

M1918

Air-cooled aircraft version of the M1917. Developed during the First World War, the M1918 arrived too late, but became the dominant weapon of its type in US service until the development of the M1919. It features a heavier barrel, but lighter barrel jacket as compared to the M1917. A sub-variant, the M1918M1, was developed as a flexible version of the fixed M1918. For anti-aircraft purposes, a double cradle was made to hold a matching pair of m/36s. The right gun, lacking sights altogether, was fed from the right, while the left gun, with iron sights complemented with an AA sight ring, was fed from left. The cocking handles were located between the guns, while safeties and triggers were individual for left and right. The special AA tripod had elongated legs and chains to either secure the tripod or hang weights on it for extra stability. The weapons were finally taken out of service in 1995. The modifications included new iron sights (V-notch rather than loophole), lengthened butt handle, lengthened barrel, simplified rifle lock for easier exchange of used-up barrels and better handling, mounting adapted for both anti-personnel and AA fire and sights and grips adapted to suit both purposes. Roughly 8,000 were built by Państwowa Fabryka Karabinów.

Colt mitraljøse m/29

thumb|right|Norwegian M/29 in anti-aircraft configuration on the [[Battles of Narvik|Narvik front, 1940]]

Norwegian designation for the Colt MG 38 (mentioned in the following section) in The Colt mitraljøse m/29 replaced the Hotchkiss M1914 machine gun in Norwegian service. The m/29 saw service in the 1940 Norwegian Campaign, often deployed as the only heavy weapon of Norwegian front line units.

Commercial variants

Colt commercially produced the M1917 under several names:

  • Colt Model of 1919 (not to be confused with the air-cooled M1919 Browning machine gun)
  • : "Type Triple-Ten" aka "Type 30", a Chinese copy of the M1917 in 7.92×57mm Mauser used in the Second Sino-Japanese War
  • : used airborne variant in 7.5×54mm as the Modèle 1938. and during the First Indochina War.
  • : FN30 variant in 6.5×54mm Mannlicher–Schönauer
  • : Model 1919 in 7×57mm Mauser