Lewis Gun
Birmingham Small Arms Company · Machine Gun · Discontinued · 1914
Also known as: Belgian Rattlesnake, Lewis Automatic Machine Gun, Lewis M1914, Lewis M1917, Savage-Lewis
Overview
The Lewis Gun is a gas-operated, air-cooled light machine gun designed in the United States in 1911 by U.S. Army Colonel Isaac Newton Lewis, building on earlier work by Dr. Samuel McClean. Immediately recognizable by its distinctive aluminum finned barrel radiator enclosed in a cylindrical cooling shroud and its top-mounted flat pan magazine, the Lewis was the first truly practical light machine gun of the modern era. Chambered primarily in .303 British, it weighed approximately 13 kg, measured 1,280 mm in overall length with a 670 mm barrel, and fired at a cyclic rate of around 550 rounds per minute from 47-round infantry or 97-round aircraft pan magazines. Rejected by the U.S. Army Chief of Ordnance General William Crozier, Lewis took his design to Belgium in 1913 and founded Armes Automatique Lewis in Liège, where the Belgian Army became the first official adopter. When World War I broke out, production moved to the Birmingham Small Arms Company (BSA) in England, which manufactured over 145,000 guns during the war, while Savage Arms in Utica, New York, produced an additional 3,550 examples for U.S. forces and British contracts. Britain officially adopted the Lewis in October 1915, and it rapidly became the standard squad automatic weapon of the British Empire, equipping infantry sections at a roughly one-per-section ratio on the Western Front from 1916 onward. German troops nicknamed it the 'Belgian Rattlesnake' for the distinctive sound of its rapid fire. The Lewis saw extensive aircraft service as an observer's and gunner's weapon in British and French biplanes, with specialized Mk II and Mk III aircraft variants featuring spade grips, removed cooling shrouds, and higher cyclic rates. More than thirty nations adopted the weapon, and although declared obsolete by the British in 1946, it served in Home Guard units throughout World War II, in Commonwealth colonial and counter-insurgency operations, and saw limited combat use as late as the Korean War and the 1948 Arab-Israeli War.
Specifications
| Weight (empty) | 13000 g (458.6 oz) |
| Overall Length | 1280 mm (50.39") |
| Barrel Length | 670 mm (26.38") |
| Action Type | Gas Operated Long Stroke |
| Firing Mechanism | Open Bolt |
| Trigger Type | Full Auto Only |
| Magazine Capacity | 47 rounds |
| Magazine Type | Drum |
| Muzzle Velocity | 744 m/s (2441 fps) |
| Muzzle Energy | 3132 J (2310 ft·lbf) |
| Effective Range | 800 m (875 yd) |
| Maximum Range | 3200 m (3500 yd) |
| Rate of Fire | 550 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 254 mm (10.00") |
| Number of Grooves | 5 |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Wood |
| Finish | Blued |
Calibers
- .303 British · primary — also known as 7.7x56mmR, .303 Enfield, Cartridge S.A. Ball .303 inch
- .30-06 Springfield — also known as 7.62x63mm, .30 Cal, .30 Gov't '06
Features
- Firing modes: Full Automatic
- Feed systems: Pan Magazine 47 Round, Pan Magazine 97 Round Aircraft
- Safety mechanisms: Manual Safety, Open Bolt System
- Features: Aluminum Cooling Radiator, Barrel Cooling Shroud, Air Cooled, Rotary Bolt Four Lug, Clock Type Recoil Spring, Top Mounted Pan Magazine, Bipod Mount, Quick Detach Magazine, Forced Air Cooling, Spade Grip Aircraft Variant
Variants
- Lewis Mk I — Infantry Ground Pattern
- Lewis Mk II — Aircraft Variant
- Lewis Mk II* — Aircraft High Rpm
- Lewis Mk III — Aircraft New Build
- Lewis Mk 4 — Simplified Production
- Lewis Mk XI SS — Naval Variant
- Savage-Lewis M1917 — American 30-06 Production
- MG 137(e) — Captured German Designation
Service history
Operators
- British Army · adopted 1915 · as Gun, Lewis, .303-inch
- Royal Flying Corps / Royal Air Force · adopted 1915 · as Lewis Gun Mk II/III
- Royal Navy · adopted 1915 · as Lewis Mk XI SS
- British Home Guard · adopted 1940
- Belgian Army · adopted 1913 · as Mitrailleuse Lewis
- United States Army · adopted 1917 · as Lewis M1917
- United States Navy · adopted 1917 · as Lewis Mark VI
- Australian Imperial Force · adopted 1915
- Canadian Expeditionary Force · adopted 1915
- New Zealand Military Forces · adopted 1915
- French Army · adopted 1915 · as Mitrailleuse Lewis
- Imperial Russian Army · adopted 1917 · as Pulemyot Lyuisa
- Red Army · adopted 1918 · as Pulemyot Lyuisa
- Irish Republican Army · adopted 1919
- Irish Defence Forces · adopted 1922
- Imperial Japanese Navy · adopted 1932 · as Type 92
- Royal Netherlands Army · adopted 1920 · as M.20 Lewis
- Polish Army · adopted 1920 · as Lewis wz. 1923
- Finnish Defence Forces · adopted 1918 · as Lewis pk/15
- Estonian Army · adopted 1919
- Norwegian Army · as Lewis mitraljøse
- Portuguese Army · as Metralhadora Lewis
- Italian Royal Army · as Mitragliatrice Lewis
- Czechoslovak Legion · adopted 1918
- Israel Defense Forces · adopted 1948
- Republic of China Army
- Philippine Commonwealth Army
- Mexican Army
- Royal Yugoslav Army
Conflicts
- World War I (1914-1918)
- Russian Civil War (1917-1923)
- Irish War of Independence (1919-1921)
- Irish Civil War (1922-1923)
- Spanish Civil War (1936-1939)
- Second Sino-Japanese War (1937-1945)
- World War II (1939-1945)
- 1948 Arab-Israeli War (1948-1949)
- Korean War (1950-1953)
- The Troubles (1960-1998)
Production
Estimated total produced: 202,000 · Production years: 1913-1942
BSA manufactured approximately 145,397 Lewis guns during World War I alone; Savage Arms in Utica produced 3,550 (2,500 in .30-06 and 1,050 in .303 for British contracts). Additional licensed production occurred in the Netherlands (Artillerie-Inrichtingen) and Japan. Total across all producers and marks commonly cited at around 200,000 units.
Origin
Country of origin: United Kingdom
Designer: Isaac Newton Lewis
Discontinued: 1953
Notes
The Lewis Gun's innovative forced-air cooling system used a finned aluminum radiator inside the barrel shroud - as the bullet exited the muzzle, it created a partial vacuum that drew air backward over the radiator fins from the receiver, providing continuous cooling without water jackets. This system was later found to be largely unnecessary, as the Mk III aircraft variant which removed the shroud entirely functioned just as well. The pan magazine is unusual in feeding rounds without an internal magazine spring - instead, the feed pawl mechanism drives rotation of the pan via stamped ribs on the magazine cover. The bolt features four radial locking lugs engaging recesses in the receiver and rotates via a cam slot on the bolt carrier. The return spring is a distinctive flat spiral 'clock-type' spring driving a gear wheel, an unusually compact solution. The Lewis was prone to jamming from the complex pan magazine, and required specialized armorers to maintain in field conditions. Despite this, it was produced in far greater numbers than the Vickers machine gun - approximately six Lewis guns could be manufactured in the time it took to produce one Vickers. The gun was also widely modified for vehicle and anti-aircraft mounts, and later British Universal Carriers commonly mounted Lewis guns. The Savage M1917 variant required modified gas regulation and a different buffer due to the higher chamber pressure of the .30-06 Springfield cartridge.
Background
Colonel Isaac Newton Lewis was so enraged when U.S. Army Chief of Ordnance General William Crozier rejected his design - reportedly for personal political reasons - that Lewis retired from the Army and took his machine gun to Belgium in 1913, founding Armes Automatique Lewis in Liège. German troops fighting the Belgian Army at the start of WWI called it the 'Belgian Rattlesnake' for the chattering sound of its distinctive 550 rpm fire. In perhaps the ultimate irony, the U.S. Army eventually had to buy Lewis guns from Savage Arms to equip its own soldiers in 1917 - rechambered in .30-06 - after refusing to adopt the original design just a few years earlier.