The Lewis 0.303 inch (7.7 mm) Mk.2 was a relatively sophisticated aircraft gun for its time. The gun was characterized especially by short length and light weight.
|Rate of fire||500 to 800rpm|
This gun was the standard aircraft machine gun for flexible mounting on Allied aircraft during the First World War. Its later variants were used in the Second World War also. Due to its basic construction the gun was not well suited for synchronized firing (through an propeller disc), but there were many fixed installations outside the arc (e.g. on the upper wing of a biplane).
The gun was designed by the American Colonel Isaac Newton Lewis and first demonstrated by him in 1911. From the beginning he had in mind to produce a design sophisticated enough not only for use with the ground forces but also in aircraft. And indeed this air-cooled machine gun was to serve later with ground troops and air forces. But at first Col. Lewis had no success with the American authorities despite a number of successful demonstrations in 1911 and 1912 (including firing trials against a ground target from a flying aircraft).
So he left the USA in 1913 for Belgium where he founded his own company "Armes Automatiques Lewis" at Liége to produce his gun. But already in 1914 he was forced to leave Belgium and went to Great Britain. There the "British Small Arms Co." ("BSA") at Birmingham finally began to produce his design.
During its long service career the gun was constantly improved and sometimes appreciably changed its appearance (as demonstrated by the versions Mk.2 and Mk.3 - the latter is lacking the barrel covering). The gun was drum-fed. The original ammunition drum housed only 47 rounds and was replaced by a 97-round drum from about 1916 on.