The Vickers K - or Vickers Gas Operated (VGO) and also officially as "Gun, machine, Vickers-Berthier, 0.303-inch, India Service Mark III" - was an aerial gun developed from the original Vickers-Berthier Light Machine Gun (LMG) for use in trainable/flexible aircraft positions. A pan magazine (60- or 100-round counts used) replaced the original's box magazine feed and it fired the standard .303 British cartridge through a gas-operated, air-cooled action. The firing rate was 900 rounds-per-minute. The operator managed the weapon through a spade grip arrangement at the rear of the receiver with iron sights set over the weapon for basic accuracy assistance. Installation on aircraft was by way of ring mounts.
As the British Royal Air Force (RAF) ultimately moved away from open-air gun positions on its aircraft, the .303 Colt-Browning became the preferred in-wing and turreted aircraft armament arrangement. After their time with the RAF had ended, the guns found renewed service lives with the British Army and made good as vehicle-mounted weapons. Special forces elements operating in North Africa found them to be exceptionally reliable and effective weapons in desert conditions when mounted on fast-moving JEEP-type platforms.
The Vickers K saw wartime service until the end in 1945 and was progressively evolved throughout the conflict.