Officers of the Cameron Highlanders of Ottawa demonstrate the Vickers machine gun. Front, left to right: Major G.F. Clingdon, Lieutenant-Colonel H.V.D. Laing. Rear, left to right: Captain Roger Rowley, Lieutenants W.H. Armstrong and G.O. Handley. Lindfield, England, 8 April 1942. Photo by Frank Royal. Department of National Defence / National Archives of Canada, PA-138338.

During the Great War, machine guns were used for both direct fire against visible targets and in an indirect role to create lethal "beaten zones" where enemy infantry could scarcely survive. In such roles they were weapons of position more than of maneuver, often sited to deliver enfilade fire laterally against a line of advancing troops. The Second World War saw the use of more mobile light machine-guns that could move with the infantry in the attack, thus increasing the rifleman's organic fire-power. A machine-gun's rapid rate of fire causes the barrel to heat up and wear out very quickly, and solutions to this fundamental problem included air- and water-cooled weapons with barrels that could be easily replaced in action.

The Vickers .303 was the same as used during the First World War, with the addition of a dial sight to increase accuracy. Its gun barrel was water-cooled to keep the temperature down during rapid fire. The Vickers was normally fired from a tripod but could also be mounted on a carrier.