The Lewis Gun, dubbed the ‘Belgian Rattlesnake’ by the Kaiser’s forces, was a revolutionary gas-operated light machine gun fielded during the Great War. Notably, the Lewis was credited with being the first weapon to shoot down a Zeppelin during the War to End All Wars.
Oh and if you’ve ever seen Star Wars, then you’ve seen the Lewis Gun. Totted around Mos Eisley by Sandtroopers, the distinctive silhouette made an old prop gun suddenly futuristic; a futurist gun straight from 1911.
When fielded the versatility of the Lewis was demonstrated by it being easily hung off the nose of a canvas-skinned bi-plane, mounted on a pintle of a motorcycle side-car, atop an armored car or even wielded by a long machine gunner high in a tree.
What made this early generation weapon so coveted, well received and pivotal? Two basic design elements made the Lewis a cut above the rest: how it was loaded and cooled.
Loading was achieved via a spring-less pan located on the top of the 28 pound gun (half the weight of a fully deployed Vickers machine gun.) The pan magazine, loaded with 47 or 97 rounds, allowed smooth mechanical feeding of .303 or .30-06 ammunition. Normally magazines are fed via a sprung under tension. The Lewis’
pan fed ammunition into the receiver at a rate-of-fire of 550 rounds per minute via a ratchet system slaved to the guns operating parts.
Importantly, the preloaded pans could be easily be transported and engaged during battle, high above the grime of the trenches, further reducing chances of fouling. And with no spring inside, the pan could be loaded without worry of the spring becoming deformed under prolonged compression, therefore increasing its chances
Contrast Lewis’ feed mechanism to that of competitors the Chauchat and Vickers/Maxim machine guns. In the case of the latter successful and extremely robust design, ammunition was fed into the Vickers via a non-disintegrating canvas belt. While very reliable, with its ancestors seeing duty in the South African military
until the 1980s, the Vickers original ammunition belt made of fabric could swell with moisture or rot in particularly humid conditions.
in the particularly muddy trenches of World War I. It was called by some the worst machine gun in history.
Another attribute that propelled the open-bolt firing Lewis to prominence was its barrel cooling method. Unlike the Maxim or Vickers, which used hefty oil or water jacket systems covering the barrels to reduce heat during sustained fire, the Lewis used a simple method of drawing cool air.
The Lewis’ barrel shroud created a negative air space inside when fired. The hot muzzle gases drew cooler air over the barrel from the back of the shroud, effectively cooling the weapon without additional equipment or weight. When mounted on aircraft during World War I the Lewis barrel shroud was removed without any effect on its reliability. During its World War II appearance Lewis’ shrouds were also removed by ground forces without negative impact on operation.
Barrel technology would eventually negate the need for a special cooling system with the creation of the quick change barrel pioneered by the MG34/42 machine guns.
As for the man who named and designed the Lewis, US Army Col. Isaac Newton Lewis, his revolutionary weapon was discarded for consideration by his own nation. Bitter from the experience Lewis moved to Belgium, started an arms manufacturing venture, enlisted the aid of the British, before finding users in the UK as well as Belgium and France; the U.S. Army Air Corps, U.S.M.C. and manufacture under license by Japan and Netherlands.
Ultimately, while the Lewis would fall out of use, supplanted by ever more efficient weapons, its legend would live on.