The Lewis Gun

The .303 calibre Lewis Gun was officially adopted by the British Army in October 1915 and was on general issue to its infantry battalions by early 1916 when its replaced the much heavier, and far less mobile, Vickers machine gun. Designed by U.S. Army colonel Isaac Newton Lewis in 1911, the Lewis Gun was based on an earlier, and more complex, design by Samuel McLean and was used with modest success by Belgian mechanised troops in the early weeks of the First World War.

Despite the obvious merits of the Lewis Gun, the U.S. Army initially rejected the opportunity to adopt the weapon and Lewis was forced to take his design to Europe in 1913 where he opened the Armes Automatique Lewis in the Belgian city of Liege in an effort to develop commercial production. The move proved critical for Lewis and the potential of his new weapon was soon recognised by the Belgian Army, who ordered a batch to undertake trials using the British .303 calibre round. With interest in the gun growing, the Birmingham Small Arms (BSA) Company purchased a licence to manufacture the weapon in 1914 and soon after, Lewis made the decision to move his entire factory to Britain.

Production of the Lewis Gun (Model 1914) increased dramatically following the outbreak of the First World War and the British Army officially adopted the weapon in October 1915. By the early months of 1916, the Lewis Gun began replacing the much-heavier Vickers Gun as the standard-issue machine gun of British infantry battalions fighting in France and Flanders. It would also be used by the Royal Flying Corps/Royal Air Force, Royal Navy, and in tanks following their introduction to the battlefield in late 1916. Initially issued on a ratio of four per infantry battalion, by mid-1918 the total had risen to 36. The same year, the U.S. Navy and Marine Corps officially adopted the M1917 model of the weapon, however, the U.S. Army remained unconvinced and would eventually opt for the Browning Automatic Rifle (BAR) as their standard-issue light machine gun.

Although the Lewis Gun was expensive to produce, it could be built much faster than the cheaper Vickers machine gun and was also much lighter and mobile on the battlefield. Air-cooled and gas-operated, the Lewis Gun could fire up to 600 rounds per minutes from its 47-round, top-mounted, pan magazine (weapons fitted to aircraft could also be used with a 97-round magazine) and had a muzzle velocity of 2,440ft/s. Its distinctive cylinder shroud design, which covered the gun’s 67cm long barrel, enabled it to draw in cool air when it was fired and its spiral recoil spring could be adjusted to regulate the rate of fire as necessary. When used with its adjustable sight and bipod, the Lewis Gun had an effective range of 800 metres and a maximum range of 3,300 metres. By the end of the First World War, more than 50,000 Lewis Guns had been issued and the weapon remains one of the most iconic of all those used by the British Army in the 20th Century.