The RPK is a 7.62x39mm light machine gun developed by Mikhail Kalashnikov, and was developed in tandem with the AKM. Towards the end of the 1950's, the Soviet Army sought to standardize its inventory of small arms. A particular target was the RPD light machine gun, a belt-fed light machine gun in the same caliber as the AKM. The Soviet Army felt that the Kalashnikov assault rifle could be modified to fulfill the role of the RPD, and worked in earnest to do so. The RPK was the result, using an AKM receiver of sturdier construction, modified buttstock and longer barrel in order to make it more suitable for this role. While it can accept standard AK magazines, it is usually fed from either a 40-round box magazine or 75-round drum. Most other components between the AKM and RPK are interchangable, a significant logistical advantage compared to the RPD, who only shares the cartridge with the AKM. In addition, it's controls and handling are similar to the AKM. The RPK was replaced in 1974 by the RPK-74, which like the RPK, is a modified AK-74 assault rifle.