The RPK is a variant of the AKM assault rifle. It has a longer, heavier barrel (591 millimeters versus 414 millimeters); a stamped metal bipod; and a heavier type of fixed, wooden buttstock. The modified receiver of the RPK can accommodate its larger-diameter barrel. The RPK normally feeds ammunition from either a 40-round curved box magazine or a 75-round spring-loaded drum magazine. However, it can also use the 30-round curved box magazine of the AKM, if necessary. It has a chrome-plated barrel, chamber. and gas piston. It also has a cyclic rate reducer built into the trigger mechanism. The Soviets usually install luminous night sights on to the front and rear sights. Some RPKs can mount an infrared night-sighting device.
The Soviets issue a folding stock version, the RPKS, to airborne troops. With stock folded, it is only 820 millimeters long (versus the RPK, which is 1,035 millimeters long).
The RPK has a maximum effective range of 800 meters in either automatic or semiautomatic mode. It also has a practical rate of fire of 150 round per minute automatic of 50 round per minute semiautomatic. In offensive operations, the machine gunner normally attaches the 75-round drum magazine beneath the weapon at the beginning of an attack. He subsequently replaces it with a 40- or 30-round magazine during the assault or in the early stages of defense. Almost all of the moving parts of the RPK and interchangable with those of the AK or AKM assault rifles.
The muzzle brake of the AK-74 a fluidic device to minimize recoil and muzzle climb. Although the AK-74 is somewhat heavier than the AKM when empty, its loaded weight is slightly less than that of the AKM; this is due primarily to the plastic magazine and its smaller-caliber ammunition. Like the AK and the AKM, the AK-74 can mount a grenade launcher and a passive image intensifier night sight.
Because the RPK fires from a closed bolt, it tends to “cook off” its cartridges after prolonged firing. Since the barrel cannot be changed, the sustained rate of fire must not exceed about 80 round per minute. The lack of a gas regulator causes rought action and vigorous ejection to the right rear when the gun is clean. It also causes the rate or fire to slow down gradually as residue and dirt accumulate in the gas port.
The Soviets first produced the RPK in 1961. It entered service around 1964. It was first displayed in the 1966 May Day parade in Red Square. It has become the standard squad automatic weapon in most Warsaw Pact armies. However, the 5.45-mm RPK-74 is now replacing Soviet units.
|Cartridge:||7.62 x 39 mm||Operation:||gas, selective fire|
|Locking:||—-||Feed:||40-round box or 75-round drum magazine|
|Weight:||5 kg empty||Length:||1.035 m|
|Sights:||fore, cylindrical post; rear, leaf notch||Muzzle velocity:||732 m/s|
|Rate of fire:||cyclic, 660 rds/min||Effective range:||800 m|