RPD
The RPD is a 7.62mm light machine gun developed in the Soviet Union by Vasily Degtyaryov for the intermediate 7.62x39mm M43 cartridge. It was created as a replacement for the DP machine gun chambered for the 7.62x54mmR Mosin rifle round. It is a precursor of most squad automatic weapons.
History[]
Work in the weapon commenced in 1943. Three prominent Soviet engineer were asked to submit their own designs: Vasily Degtyaryov, Sergei Simonov and Alexei Sudayev. Among the completed prototypes prepared for evaluation, the Degtyaryov design proved superior and was accepted into service with the Soviet armed forces as the 7.62mm "Degtyarov light machine gun" model 1944. Although the RPD was ready for mass production during the final stages of WWII, large scale delivery of the weapon did not begin until 1953. During the Vietnam War, the RPD served the Vietcong as their standard gerneral purpose machine gun.
After the introduction of the Kalashnikov-pattern support weapons such as the RPK and PK machine guns in the 1960s, the RPD was withdrawn from most first-tier units of the former Warsaw Pact. However, the RPD remains in active service in many African and Asian nations. Apart from the former Soviet Union, the weapon was manufactured in China, Egypt, North Korea, and since 1956-Poland.
Design details[]
Operating mechanism[]
The RPD is an automatic weapon using a gas-operated long stroke piston system and a locking system recycled from previous Degtyaryov small arms, consisting of a pair of hinged flaps set in recesses on each side of the receiver. The movement of these flaps and the resulting locking and unlocking action is controlled by carefully angled surfaces on the bolt carrier assembly. The weapon fires from an open bolt.
Features[]
An Egyptian marine aims his RPD.
The RPD is striker fired and features a trigger mechanism that is limited to fully automatic fire only. The bolt is equipped with a spring loaded casing extraction system and a fixed insert inside the receiver housing serves as the ejector. Spent cartridge casings are ejected downward through an opening in the bolt carrier and receiver. The RPD has a manually operated lever-type safety mechanism that secures the weapon against accidental firing by blocking the bolt catch when engaged. Unlike Degtyaryov's earlier firearm patents, the RPD's return spring is located inside the butt. Like many other Russian-made firearms, the chamber and bore are chrome-lined, greatly decreasing the risk of corrosion and jamming.
The weapon has a non-removeable barrel with a 3-position gas adjustment valve used to control the performance of the gas system. It is also equipped with a folding integral bipod, wooden shoulder stock, foregrip and pistol grip. The firearm strips down into the following major groups: the receiver and barrel, bolt, bolt carrier, feed tray and feed cover, the recoil mechanism and the trigger group and stock.
Feeding[]
RPD from a Polish Army depot.
The machine gun feeds from the left-hand side from a segmented, open-link metallic belt (each segment holds 50 rounds). Two combined belts (linked by cartridge) containing a sum total of 100 rounds are stored in a metal container resembling a drum, attached to the base of the receiver or the gun can simply be fed by a loose belt without a drum magazine with a longer desired length rather than 100 rounds if need be. The feed system is operated by a roller connected to the reciprocating bolt carrier assembly and the belt is pulled during the rearward motion of the bolt carrier. Noteworthy is that the drum magazine's design flaw is the fact that it is unreliable in dirty conditions and can become clogged with filth and other natural elements if they enter the magazine.
Sights[]
A US Marine sights in with the RPD.
The LMG is equipped with a set of open-type iron sights. These consist of a front post (adjustable for windage and elevation) and a notched rear sight mounted on a tangent with a sliding elevation adjustment knob and marked with range indicators from 100 to 1,000m. A number of machine guns were fitted with a side rail, used to mount the NSP-2 night vision sight.
Accessories[]
Standard accessories supplied with the weapon include an ammunition container, extra belts, a cleaning rod (carried on the left side of the receiver), cleaning kit (stowed in a compartment inside of the stock), sling and pouches for the ammunition drums. (Although not designed for such a position, an RPD is capable of being fired from the hip by utilizing the sling to hang the gun over the user's shoulder).
Variants[]
During its service life, the weapon was modernized several times. Initially, the gas block was modified as was the rear sight., where the windage adjustment knob for the rear sight was moved to the left side of the notch. Later, the RPD was modified with a non-reciprocating cocking mechanism with a folding charging handle (replacing the fixed charging handle connected to the bolt carrier) that does not move during firing. The feed port received a dust cover, which when open, serves as a feeding ramp for the ammunition belt. This version of the light machine gun was produced mainly in China and Poland. A further modified variant (sometimes referred to as the RPDM) includes an extended gas cylinder and a recoil buffer mechanism in the stock. Late production RPD variants also had the fixed drum attachment removed (instead, the ammunition container was "hung" from the feed port cover) and feature a folding cleaning rod, that is stored in the weapon's butt.