Vz. 52 machine gun  The vz. 52 ("7,62mm lehký kulomet vzor 52") is a Czechoslovak light machine gun developed after the Second World War for the Czechoslovak Armed Forces. The vz. 52 was originally called the ZB 501, and was designed by Václav Holek. It is gas-operated and uses a tilting bolt that locks into the roof of the receiver. Its overall action is based on the Czech ZB-26 light machine gun. It has an integral bipod and interchangeable barrels, and its feed system is designed to take metallic belts or box magazines interchangeably and without any modifications. The vz. 52 initially used the Czech 7.62×45mm vz. 52 cartridge, but in the mid-1950s it was converted to the standard 7.62×39mm Warsaw Pact round by Jaroslav Myslík, and named the vz. 52/57. Both models were replaced in Czech service in 1963–64 by the Universal Machine Gun Model 1959, also known as the Uk vz. RP-46 URZ AP Taden gun Type 73 light machine gun