The RPD (, English: Degtyaryov hand-held machine gun) is a 7.62x39mm light machine gun developed in the Soviet Union by Vasily Degtyaryov for the 7.62×39mm M43 intermediate cartridge. It was created as a replacement for the DP machine gun chambered for the 7.62×54mmR round. It is a precursor of most squad automatic weapons. It was succeeded in Soviet service by the RPK. History Work on the weapon commenced in 1943. Three prominent Soviet engineers were asked to submit their own designs: Vasily Degtyaryov, Sergei Simonov and Alexei Sudayev. Among the completed prototypes prepared for evaluation, the Degtyaryov design proved superior and was accepted into service with the Soviet armed forces as the 7.62 mm Ручной Пулемёт Дегтярёва, PПД (RPD, Ruchnoy Pulemyot Degtyaryova or "Degtyaryov light machine gun") model 1944. Although the RPD was ready for mass production during the final stages of World War II, it was adopted in 1948 and large scale delivery of the weapon did not begin until 1953. During the Vietnam War, the RPD and its Chinese copy (Type 56) served the Viet Cong and the People's Army of Vietnam as their standard light machine gun. After the introduction of the Kalashnikov-pattern support weapons, such as the RPK and PK machine guns in the 1960s, the RPD was withdrawn from most first-tier units of the former Warsaw Pact. However, the RPD remains in active service in many African and Asian nations. Apart from the former Soviet Union, the weapon was manufactured in China (as the Type 56 LMG), Egypt (Maadi RPD), North Korea (Type 62) and, since 1956, Poland. Design details Operating mechanism The RPD is an automatic weapon using a gas-operated long-stroke piston system and a locking system recycled from previous Degtyaryov small arms, consisting of a pair of hinged flaps set in recesses on each side of the receiver. The movement of these flaps and the resulting locking and unlocking action is controlled by carefully angled surfaces on the bolt carrier assembly. The weapon fires from an open bolt. Features The RPD is hammer fired from an open bolt. The hammer forms part of the rear of the bolt carrier (which is connected to the gas piston), which continues moving forward for a short distance after the round is chambered and the bolt locked, the hammer face then striking the rear of the free floating firing pin which passes through the length of the