The 7.62×39mm round is a rifle cartridge of Soviet origin that was designed during World War II. The 7.62x39mm was first used in the RPD. Due to the worldwide proliferation of the SKS and AK-47 pattern rifles, the 7.62x39mm cartridge is used by both militaries and civilians alike. 7.62×39mm ammunition is purportedly tested to function well in temperatures ranging from −50 to 50 °C (−58 to 122 °F) cementing its usefulness in cold polar or hot desert conditions.
The 7.62×39mm cartridge was influenced by a variety of foreign developments, including the German Mkb 42(H) and the U.S. M1 carbine.
Shortly after the war, the world’s most widespread military-pattern rifle was designed for this cartridge: the AK-47. The 7.62x39mm cartridge remained the Soviet standard until the 1970s, and is still one of the most common intermediate rifle cartridges used around the world. It was replaced in Russian service by the 5.45×39mm cartridge, which is used by the current-issue AK-74 and its variants.