Degtyaryov machine gun

The Degtyaryov machine gun (Russian: Пулемёт Дегтярёвa Пехотный Pulemyot Degtyaryova Pekhotny "Degtyaryov's infantry machine gun") or DP is a light machine gun firing the 7.62×54mmR cartridge that was used primarily by the Soviet Union starting in 1928. The DP machine gun was supplemented in the 1950s by the more modern RPD machine gun and entirely replaced in Soviet service by the general purpose PK machine gun in the 1960s.

Design

The DP-27 was an improvement of the earlier DP-26, both designed by Vasily Degtyaryov. The DP-27 was relatively cheap and easy to manufacture – early models had fewer than 80 parts. The DP was especially able to withstand dirt in a reliable fashion. In tests it was buried in sand and mud and was still capable of firing more than 500 rounds. One of the DP's main drawbacks though was its bipod; it could not withstand much abuse and broke easily. Furthermore, the recoil spring was located under the barrel, around the gas piston; this was one of the design problems of the DP, since the spring tended to lose its temper due to overheating. Also, the only magazine option, a pan with 47 rounds that fed in from the top, was relatively small and continuous fire for long periods could not be relied on as much as contemporary belt-fed weapons. The ammunition was troublesome for automatic fire. Degtyarov had to use a flat pan magazine, which could feed those cartridges reliably, but was too heavy itself, uncomfortable to carry and prone to damage. Due to the design of the magazine, reloading an empty magazine with cartridges took a very long time. A redeeming factor was that the DP's lower cyclic rate of fire did reduce the risk of barrel overheating.