Editing Degtyaryov machine gun (section)

== System ==
The Degtyaryov light machine gun (DP) operates using a [[gas-operated reloading|gas-operated]] mechanism and magazine-fed ammunition. The gas engine features a long-stroke piston and a gas regulator located under the barrel.

The [[Barrel (firearm)|barrel]] itself is quick-detachable, partially covered by a protective shroud, and equipped with a conical removable flash hider (early models lacked both a flash hider and threading for it). The barrel was prone to overheating during intensive fire: due to its thin walls, it would heat up quickly (especially in later models where ribbed radiators were omitted for simplicity), and thus short bursts were necessary to prevent disabling the gun (combat rate of fire was up to 80 rounds per minute). Replacing the barrel during combat was difficult—it required a special wrench to remove the lock and protect the hands from burns.

The bolt was locked using two locking lugs that spread sideways when the [[Firing pin (firearm)|firing pin]] moved forward. Once the bolt reached the forward position, the bolt carrier continued moving, and the widened middle section of the firing pin, connected to it, pushed the rear ends of the locking lugs outward into the grooves of the receiver, securely locking the bolt. After firing, the bolt carrier moved backward under the action of the gas piston. During this, the firing pin was retracted, and special bevels on the carrier brought the locking lugs inward, disengaging them from the receiver and unlocking the bolt. The [[recoil spring|recoil-operating spring]] was located under the barrel and could lose elasticity when overheated during intense fire, which was one of the relatively few but significant disadvantages of the DP. Additionally, the locking lugs required precise fitting to achieve symmetrical locking (though this was not a major practical drawback).
[[File:Kiev ukraine 966 army museum (11) (5869944940).jpg|thumb|Cartridges were arranged in a circle, with bullets facing the center of the disk.]]
The weapon was fed by flat pan magazines—“platters”—in which cartridges were arranged in a circle with bullets facing the center. This design ensured reliable feeding of rimmed cartridges but had notable drawbacks: large size and weight of the empty magazine, difficulty in transport and reloading, and susceptibility to damage during combat due to deformation. Initial magazines held 49 rounds, later replaced by 47-round ones with improved reliability. The machine gun was issued with three magazines and a metal box for their transport.

Although the DP magazine externally resembled the magazine of the [[Lewis gun]], its operating principle was entirely different; for example, in the Lewis gun, the disk rotated using energy from the bolt via a complex lever system, while in the DP, it was powered by a pre-tensioned spring inside the magazine.

[[File:DP disk up.jpg|thumb|Top view of DP drum magazine]]
[[File:DP disk down.jpg|thumb|Bottom view of DP drum magazine]]
[[File:DP disk mag cartridge.jpg|thumb|Magazine lips]]

The trigger mechanism allowed only fully automatic fire from an open bolt. It was housed in the trigger frame, attached to the receiver with a cross-pin. There was no conventional safety; instead, it had an automatic [[safety (firearm)|safety]] lever that disengaged when gripping the [[pistol grip|neck of the stock]]. During intense fire, the need to constantly press the safety lever tired the shooter, and the rifle-type stock did not aid in maintaining a firm grip during burst fire. The tank version, the DT, had a more successful trigger frame design, featuring a standard safety and a pistol grip. The upgraded version, the DPM, adopted a similar trigger frame. Interestingly, Finnish-modified DPs during overhaul were fitted with a manual safety in addition to the original automatic one.

The DP was fired using a detachable bipod ([[bipod (firearm)|bipod]]), which was sometimes lost in the heat of battle due to insecure attachment or became loose, significantly reducing stability and ease of use. The DPM later adopted a fixed bipod. Spent casings were ejected downward.

=== Accessories ===
The machine gun's accessories include<ref>{{cite book|date=1939 |location=Москва |publisher=Государственное военное издательство НКО СССР |title=Наставление по стрелковому делу (НСД-38) ручной пулемёт ДП}}<!-- auto-translated from Russian by Module:CS1 translator --></ref>:
* a '''sectional cleaning rod''' for cleaning the barrel bore;
* a '''wrench-screwdriver''' for disassembly and assembly;
* a '''crank cleaning rod''' with a bristle brush for cleaning the chamber through the top receiver port without full disassembly;
* a '''gas path cleaning tool''';
* '''two drifts''' for pushing out pins and dowels;
* an '''extractor''' for removing torn cartridge case necks.
All accessories were packed in a box-bag or a canvas pouch.

=== Sound Suppressor ===
At the end of 1941, the SG-DP (Special Sound Suppressor for the “DP” LMG), likely developed with I.G. Mitin's involvement, was created. It used low-charge rounds with light bullets, reaching a muzzle velocity of 330 m/s. The suppressor enabled silent automatic fire up to 300 m (with a lethal range of up to 500 m). It was adopted by the [[Red Army]] on May 27, 1942. In June 1942, Plant No. 2 of the NKVD in [[Kovrov]] planned to produce 500 units<ref>{{cite web
 |last=Chumak
 |first=Ruslan
 |title=Ленинградские «Брамиты»
 |work=Журнал «Калашников»
 |issue=5
 |year=2015
 |pages=34–36
 |url=http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2015/kalashnikov_05_2015.php
 |archive-url=https://web.archive.org/web/20150925094331/http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2015/kalashnikov_05_2015.php
 |archive-date=2015-09-25
 |access-date=2015-09-12
 |language=ru
}}</ref>. The suppressor weighed 1.3 kg, and the overall length of the machine gun with it was 1332 mm<ref name="Kalashnikov 98">{{cite web
 |last=Chumak
 |first=Ruslan
 |title=Звук выстрела совершенно отсутствует…
 |work=Журнал «Калашников»
 |issue=8
 |year=2014
 |page=98
 |url=http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2014/kalashnikov_08_2014.php
 |archive-url=https://web.archive.org/web/20151118035742/http://kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2014/kalashnikov_08_2014.php
 |archive-date=2015-11-18
 |access-date=2015-09-13
 |language=ru
}}
</ref>.

After testing in July 1942, the SG-DP was revised at Kovrov's OKB-2 by designers A.M. Marantsev and I.V. Dolgushev. The improved suppressor had a reduced inner diameter from 16 to 14.5 mm. It weighed 1.15 kg, had an 85 mm muzzle attachment, and an overall length of 291 mm<ref name="Kalashnikov 98"/>.

[[File:SnowStepDPOrig.jpg|thumb|Snowshoe for the DP LMG]]
[[File:SnowstepDP27.jpg|thumb|DP-27 with replica snowshoe]]
In late 1942, the suppressor was tested at the [[Central Scientific Research Proving Ground for Small Arms and Mortars|NIPSVO]] as the SG-42 (Special Suppressor Model 1942). It was presumably used at the front and mass-produced, although production volume is unknown. Postwar tests in February–March 1948 found the suppressors unreliable, and they were decommissioned<ref>[http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2010/8_2010.php Журнал «Калашников» № 8/2010. Yuri Ponomaryov “Biography of PBS”, p. 30] {{webarchive|url=https://web.archive.org/web/20140812211921/http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2010/8_2010.php}}</ref><ref name="Kalashnikov 99">{{cite web
 |last=Chumak
 |first=Ruslan
 |title=Звук выстрела совершенно отсутствует…
 |work=Журнал «Калашников»
 |issue=8
 |year=2014
 |page=99
 |url=http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2014/kalashnikov_08_2014.php
 |archive-url=https://web.archive.org/web/20151118035742/http://kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2014/kalashnikov_08_2014.php
 |archive-date=2015-11-18
 |access-date=2015-09-13
 |language=ru
}}
</ref>.

Between 1948–1950, the suppressor was further developed into the KB-P-535 at OKB-2. It weighed 0.96 kg with obturators, measured 301 mm in length, 68 mm in height, and 34 mm in width. The DP with this suppressor measured 1310 mm<ref name="Kalashnikov 99"/>.

In March–April 1950, the KB-P-535 suppressors were tested with the [[RP-46]] machine gun but again failed to meet requirements<ref name="Kalashnikov 99"/><ref>[http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2010/9_2010.php Журнал «Калашников» № 9/2010. Yuri Ponomaryov “Biography of PBS. Continuation” p. 28] {{webarchive|url=https://web.archive.org/web/20150504172243/http://www.kalashnikov.ru/Kalasnikov/Arhiv_Kalashnikov/2010/9_2010.php}}</ref>.

=== Snowshoe ===
Due to the legs of the machine gun sinking into snow or loose soil, various devices were developed, such as the snowshoe.

The snowshoe for the DP consists of metal plates hinged together with a stretched canvas fabric. Two of the plates, with eyelets and straps, are used to attach the bipod legs, while a canvas strap with buckle secures it to the trigger guard.

The snowshoe supports the DP during firing from deep snow, swampy, or sandy ground in summer<ref>{{cite book
 |editor1-last=Glazatov
 |editor1-first=V.V.
 |editor2-last=Gorina
 |editor2-first=M.E.
 |editor3-last=Musatova
 |editor3-first=E.A.
 |title=Памятка по применению в зимних условиях волокуш, лыжных установок и снегоступов для пулемётов, противотанковых ружей, миномётов и боеприпасов к ним
 |year=1944
 |location=М.
 |publisher=Военное издательство Народного Комиссариата Обороны
 |pages=6–7
 |language=ru
}}</ref>.

Magazines and ammunition could also conveniently be placed on the snowshoe.