Semi automatic rifles military firearm that is chambered for ammunition of reduced size or propellant charge and that has the capacity to switch between semiautomatic and fully automatic fire. Because they are light and portable yet still able to deliver a high volume of fire with reasonable accuracy at modern combat ranges of 1,000–1,600 feet (300–500 metres), assault rifles have replaced the high-powered bolt-action and semiautomatic rifles of the World War II era as the standard infantry weapon of modern armies.
A hint at this new weapon had been given during World War I, when Vladimir Grigorevich Fyodorov, father of Russian automatic weapons, married the 6.5-mm cartridge of the Japanese Arisaka rifle to an automatic rifle. In 1916 he unveiled his new weapon, the Avtomat Fyodorova. Owing to the turmoil of the Russian Revolution of 1917, only about 3,200 of Fyodorov’s weapons were delivered. Nevertheless, they pointed the way to future infantry weapon design.
During World War II, Hugo Schmeisser designed a light rifle to fire the Germans’ 7.92-mm Kurz (“Short”) cartridge, which was of the same calibre as the Mauser rifle cartridge but was lighter and shorter and was therefore of a less-potent “intermediate” power. The weapon, known variously as the MP43, MP44, or Sturmgewehr (“Semi automatic rifles”) 44, was loaded by a curved box magazine holding 30 rounds and was designed for most-effective fire at about 300 yards (270 metres). Only some 425,000 to 440,000 of these rifles were built—too few and too late for the German war effort—but they were based on a concept that would dominate infantry weapons into the 21st century.