The term WORLD WAR II GUN can be summarized as a Sten gun, which was a British submachine gun used during World War II. It was designed in 1940 and was made of inexpensive materials, making it easy to mass-produce. It was used by British and Commonwealth forces throughout the war and was also supplied to the Soviet Union and other Allied nations. The Sten gun was reliable and effective, and it was one of the most widely used weapons of World War II.