Degtyaryov machine gun
The Degtyaryov machine gun (Russian: Пулемёт Дегтярёва Пехотный (ПДП), romanized: Pulemyot Degtyaryova Pekhotny (PDP), lit. 'Degtyarev Infantry Machinegun' or DP-27/DP-28 is a light machine gun chambered in the 7.62×54mmR cartridge that was primarily used by the Soviet Union, with service trials starting in 1927, followed by general deployment in 1928. Besides being the standard Soviet infantry light machine gun (LMG) during World War II, with various modifications it was used in aircraft as a flexible defensive weapon, and it was equipped on almost all Soviet tanks in WWII as either a flexible bow machine gun or a co-axial machine gun controlled by the gunner.