M1 40mm Bofors Anti-Aircraft Artillery

The most significant light antiaircraft gun of World War II was the 40mm gun made by made by Bofors, a Swedish manufacturer. The design was developed in Sweden during the 1930s and was adopted for American military use, first by the Navy in 1938 and by the Army in 1941. Production was initially small and most guns were delivered to the Navy, but by early 1943 the 40mm Bofors reached Army antiaircraft units in quantity.