The RPK (, English: "Kalashnikov hand-held machine gun"), sometimes retroactively termed the RPK-47, is a Soviet 7.62×39mm light machine gun that was developed by Mikhail Kalashnikov in the early 1960s, in parallel with the AKM assault rifle. It was created to standardize the small arms inventory of the Soviet Army, where it replaced the 7.62×39mm RPD light machine gun. The RPK continues to be used by the armed forces of countries of the former Soviet Union and certain African and Asian nations. The RPK is also manufactured in Bulgaria, Romania and Serbia. Design details Operating mechanism The RPK functions identically to the AK-47. It also uses the same 7.62×39mm ammunition. It has a similar design layout to the Kalashnikov series of rifles, with modifications to increase the RPK's effective range and accuracy, enhance its sustained fire capability, and strengthen the receiver. Features The RPK features a thicker and longer barrel than the AKM. This allows for it to be fired for longer without permanent loss in accuracy due to the barrel heating up. The chrome-lined barrel is permanently fixed to the receiver and cannot be replaced in the field. It is fitted with a new front sight base, and the gas block lacks both a bayonet lug and an under-barrel cleaning rod guide. The barrel also features a folding bipod mounted near the muzzle, and a front sight base with a lug that limits the bipod's rotation around the axis of the barrel. The barrel has a threaded muzzle, enabling the use of muzzle devices such as flash hiders, compensators, and blank-firing adapters. When a muzzle device is not being used, the threads on the muzzle can be covered by a thread protector. The barrel is pinned to the receiver in a modified trunnion, reinforced by ribbing, and is slightly wider than the trunnion used on the standard AKM type rifles. Symmetrical bulges on both sides of the front trunnion ensure a proper fit inside the receiver. The RPK also has a slightly longer receiver, by about 20 mm or less. This was done to decrease the fire rate slightly, but not significantly enough to lower it any less than 600 rounds per minute. The U-shaped receiver is stamped from a smooth sheet of steel compared to the sheet metal receiver used on the standard AKM rifles. It uses a modified AKM recoil spring assembly that consists of a rear