12.7mm Russian and Chinese .50-caliber Machine Guns
January 04, 2018
Whenever one hears mention of a .50-caliber machine gun, or "fifty-cal" in common U.S. military parlance, the designs of John Browning most frequently come to mind. Specifically, the M2 .50-caliber Browning Machine Gun (BMG), nicknamed "Ma Deuce," and its variants have been in use by the U.S. and most western militaries for nearly a century. However, outside the U.S. and western sphere of influence, most of the world's militaries more commonly associate the .50-caliber (12.7mm) heavy machine gun with two Russian designers: Vasily Degtyarov and Georgi Shpagin.
Both Degtyarov and Shpagin were accomplished Russian smallarms designers in the interwar years. During the Second World War, machine guns designed by both men were widely issued to Russian troops and their allies. Degtyarov developed the DP-series Light Machine Gun (LMG), which was the standard Russian infantry squad light machine gun, serving a role similar to the American BAR and the British Bren LMGs. The heavy-barrel DT variant of the DP was used in many Russian armored vehicles in a coaxial mounting, while the DA variant was used in aircraft. The DP, DT and DA all featured a signature top-mounted frying-pan-shaped magazine for the rimmed 7.62x54R cartridge. Shpagin designed the more well-known PPSh-41 submachine gun. Simple, reliable, inexpensive to manufacture and with more than 6 million produced, the PPSh-41 was ubiquitous among all Russian forces.
One of the last projects that Degtyarov worked on prior to his death in 1949 was the RPD belt-fed LMG. The RPD was chambered for the then cutting-edge intermediate-caliber 7.62x39mm cartridge. Degtyarov's RPD can be considered the doctrinal predecessor of modern belt-fed intermediate-caliber squad LMGs such as FN's M249 SAW.
DShK and DShKM
The development of Russian and Chinese .50-caliber Heavy Machine Guns (HMG), like their American M2 BMG counterpart, was inspired by the German TuF 13mm HMG. In the waning days of the First World War, German designers modified their successful MG08 7.92x57mm Maxim Gun to fire a larger 13mm cartridge for use in tanks and aircraft. In 1925 Degtyarov began similar work on a HMG design chambered for the Russian 12.7x108mm cartridge. Degtyarov essentially did what Browning had done nearly a decade earlier by enlarging an existing medium-caliber design, the M1919 .30-caliber Browning, to .50 caliber. In Degtyarov's case, the DP 7.62x54R LMG design was enlarged to accommodate the 12.7x108mm cartridge.
The enlarged 12.7mm version was designated DK (Degtyarov Krupnokalibernyj, or large caliber) and went into limited production in 1933. There was one major problem with the DK, however. Unlike the belt-fed Browning M2, the DK was fed by a top-mounted 30-round drum magazine. The heavy, cumbersome drum with limited ammo capacity was found to be unsuitable, and another designer was brought in. Shpagin developed a belt-feed assembly for the DK that bolted on to the former magazine well. This enhancement resulted in a new model, the DShK (Degtyarov-Shpagin Krupnokalibernyj), commonly spoken as "Dishka," which translates as "sweetheart."
The DShK entered series production in 1938, and its features remained largely unchanged throughout the Second World War. The DShK's Shpagin-designed belt-feed assembly featured a rather delicate rotary-wheel feeder turned by an exposed fork-like sprocket arm. This arm was actuated by an external pin on the reciprocating bolt carrier. The DShK is long-stroke gas operated and used a set of flap locks to lock the action at the moment the cartridge fired. It fires from an open bolt and is fully automatic only. The extensively finned barrel is technically removable, and the gas system is adjustable, but both require special tools to do so. It's rather unrefined but works well enough to be put into production.
During the postwar period Shpagin eventually developed an improved belt feeder with the simpler slider-type mechanism, but his signature sprocket arm remained. The updated model came out just after the war in 1946 and was designated DShKM, where the "M" stands for "modernized." While most western tank designs of the period featured an anti-aircraft machine gun located on top of the turret, it was not until the JS-2 heavy tank of 1944 that Russian tanks had one. The JS-2 mounted an original DShK, and the trend was continued with the mounting of the DShKM on the mass-produced T-54/55- and T-62-series Main Battle Tank (MBT).
A note on the famous Degtyarov flap lock: It was actually invented by two Swedes. In 1870, a Swedish army officer named D.H. Friberg was the first to patent the flap-lock mechanism that is activated by an oversize firing pin. It wasn't until 1906 that another Swede, Rudolf Kjellman, put this flap lock in an machine gun. Degtyarov began to use his version of the flap lock in his designs by the 1920s. The main difference between his and the Swedish design is that the Kjellman-Friberg locking flaps are forward opening, while the Degtyarov locking flaps open backward. Degtyarov's modification also uses bigger flaps for both ease of manufacturing and to make the flaps structurally stronger. Even later, the Grossfuss roller lock found on the German MG42 was basically a further evolution of Kjellman-Friberg flap lock using two movable rollers in place of the flaps.
The DShKM was replaced in the 1970s by the much lighter NSV (Nikitin, Sokolov and Volkov, its three designers). The NSV uses the proven long-stroke gas system of the DShKM, but has a practical adjustable gas regulator and quick-change barrel. The action is locked before firing by tilting the whole bolt assembly to the left side of the receiver. In its tripod-mounted configuration, the NSV is some 200 pounds lighter than the old DShK on its wheeled carriage with gun shield. The NSV was first seen mounted on the Russian T-64 and T-72 MBT. Today only Serbia and Poland still produce the NSV. The Poles manufacture a version of the NSV that accepts 12.7x99mm NATO (.50 BMG) cartridge. A number of Polish NSV machine guns were sold to the new Iraqi army. In Russian service, the NSV has been superseded by a newer .50-caliber HMG design not because of obsolescence, but due to geopolitical considerations. After the fall of the Soviet Union, the factory producing the NSV was owned by the breakaway Republic of Kazakhstan.
The NSV now shares duty in the Russian military with the KORD (Konstruktsija Oruzheinikov Deytyarovtsev). The KORD name was a departure from the Russian smallarms naming tradition. It's actually named after the Deytyarov Factory design team instead of the lead designer. The KORD is made by ZID (Zavod imeni Deytyarova), a factory named to honor the legacy of Vasily Degtyarov. Work on the KORD began a few years before the breakup of the Soviet Union and was expedited after the Russians lost the NSV production facility. Still, the KORD didn't enter service until 2001. It features an adjustable long-stroke gas system with a quick-change barrel similar to the earlier Russian DShKM. The action is locked by a modern rotating bolt. A .50-caliber BMG version of the KORD was included early in development. The KORD has a few unique features, including a forward-ejecting tube and a belt-feed mechanism configurable for feeding from either direction with minimal effort. There is also a portable infantry bipod kit available consisting of the recoil-reducing free-float mounting cradle with a bipod in the front and a pistol grip with buttstock at the back. The KORD shares the same tripod and vehicle mount as the NSV.
Chinese .50-Caliber Heavy Machine Guns
China received the production license and tooling to make the DShKM from the Russians in the early 1950s. The Chinese produced the DShKM, designated the Type 54, which served as the primary Chinese vehicle-mounted HMG into the late 1990s. However, due to a split in Sino-Russian relations in the early 1960s, all Russian military technology transfers ground to a halt. This impasse was the turning point from which the Chinese began work on their own .50-caliber HMG design. Unlike the Russians, the Chinese didn't find the battle-proven Degtyarov-Shpagin design to be outdated. In fact, all but one of the subsequent Chinese .50-caliber HMGs retained some element of the basic Degtyarov-Shpagin design. The development of indigenous Chinese .50-caliber HMGs branched into two camps by the 1970s. The Chinese People's Liberation Army (PLA) Armor Corps retained the traditional heavy-duty HMG design with a heavy barrel. The PLA Infantry Corps, on the other hand, wanted a more portable, lightweight machine gun.
Type 77 and Type 85
The first attempt at developing an indigenous Chinese .50-caliber HMG resulted in the odd-looking Type 77. It is essentially a streamlined Degtyarov-Shpagin layout with a direct-gas-impingement action, unusual for a machine gun. The receiver consists of a seamless steel tube with the heavy fluted barrel attaching directly to it. The tubular bolt group uses a set of Degtyarov flap locks, and its feed tray is a modified Shpagin design with the sprocket arm relocated inside the unit. Due to the direct-gas operation, the Type 77 rate of fire is a rather high 700 to 800 rounds per minute. A removable shoulder stock can be attached to the rear of the receiver for additional support.
Lighter weapon weight was one of the main design objectives in the Type 77 as well as all following Chinese .50-caliber HMGs. In the Type 77, weight savings were achieved through the elimination of the gas piston assembly due to direct-gas-impingement operation and use of a simpler tripod with tubular legs instead of the heavy wheel carriage and tripod used by the Type 54/DShKM. The total weight with tripod is half that of the Type 54/DShKM. In the 1980s, a large numbers of Type 77s were given to the Mujahedeen during the Soviet invasion of Afghanistan. These posted a significant threat to low-flying Russian helicopters during that war. Many of those same Type 77 HMGs are now in the hands of Taliban forces and being used against U.S. and NATO forces in Afghanistan.
The follow-up Type 85 model replaced the dual spade grip and triggers with a Czech-influenced right-side-mounted firing mechanism with a pistol grip. The pistol grip also serves double duty as the cocking handle to pull back the bolt. A simpler double-baffle muzzlebrake on the Type 85 also replaced the pepperbox-type of the Type 77. The total weight was further reduced by a new lighter tripod using two U-shaped rear legs made from steel stampings. The W95 is a Type 85 variant chambered for the 12.7x99mm NATO round available for export.
W85 and the QJC-88
The next series of Chinese HMG began with the W85, also a modernized and simplified Degtyarov-Shpagin-based design. In contrast to the DShKM, however, all the cooling fins are gone and the barrel can be quickly removed with a flip of a locking lever. A new long-stroke gas system employs a real adjustable gas regulator. The receiver was scaled down to reduce weight in the same fashion as the American Browning AN/M2, the aircraft-mount lightweight variant of the .50-caliber M2 Browning HMG. The W85 feed tray is still based on the Shpagin design but is flipped around with the sprocket arm now at the front. The bolt is locked via a pair of front-opening smaller Kjellman flaps instead of the rear-opening massive Degtyarov-type of flaps. The W85 uses the same tripod and mounting interface as the Type 85 HMG series. The W85 rate of fire is also much lower than that of the direct-gas-driven guns at 540 to 600 rounds per minute. Besides some Chinese militia and reserve units, most users of the W85 are foreign.
The QJC-88 is an improved W85 optimized for a vehicle mount. It was chosen by the PLA Armor Corps as the replacement for the Type 54/DShKM in its vehicles. The QJC-88 receiver is shorter than the W85 with more weight-saving cuts. The QJC-88 is normally mounted in a dedicated pintle mount with a vertical hydraulic balancer that maintains the elevation angle. The trigger is on the left handle and connected to the firing mechanism via a cable. The right handle is mounted on a roller disk that controls elevation. A slot-machine-like charging handle is located on the upper-left side of the unit. The primary sight is a reflex-type stowed in a round box. The iron sight on the QJC-88 is retained as the backup sight.
There are nine different sub-variants of the QJC-88. Seven of those are various vehicle-mount models, including a remote weapon station. The other two are a navalized version and a lightweight infantry version that has been seen with a heavily fluted light barrel. The infantry version of the QJC-88 uses the existing Type 85 tripod system.
Unlike the other Chinese designs, the QJZ-89 was developed from the start as a truly infantry-portable .50-caliber HMG. It's also a complete departure from the Degtyarov-Shpagin design. The QJZ-89 uses a combination of direct-gas impingement and short recoil operation with a modern rotating-bolt lock. This action type is more commonly found on aircraft automatic cannons where the weight savings are essential. The short-recoil part of the action uses the mass of the bolt group and the barrel to soak up most of the peak recoil force. The direct-gas system is used to cycle the action. The American XM312 lightweight experimental .50-caliber HMG employs a similar hybrid gas- and recoil-operated action.
The QJZ-89 design team used a number of methods to reduce weight. The box-shaped receiver is constructed from welded steel stampings. This contributes greatly to the overall lighter weight and lower manufacturing cost as compared to the milled receivers of other Chinese HMGs. The barrel is heavily fluted and has a large triple-baffle muzzlebrake. The rotating bolt locks into the barrel extension directly similar to an AR-15, which further minimizes firing stress to the receiver. The rate of fire is slowed to 450 to 500 rounds per minute by use of a pneumatic buffer. A new tripod weighs only 18.7 pounds and is made from all U-shaped stamped steel legs. The ammo box and all port covers on the receiver are made from aluminum alloy. The end result of these efforts is a remarkably light .50-caliber HMG that only weighs 38½ pounds alone, just a few pounds heavier than the .30-caliber M1919 Browning Medium Machine Gun, and 57½ pounds with the tripod.
On an interesting note, the QJZ-89 lightweight .50-caliber HMG and the 25-pound QLZ-87 35mm Automatic Grenade Launcher (AGL) are being used in a novel attempt by Chinese ground forces to redefine their machine-gun doctrine. Both of those lightweight, crew-served machine guns are being issued in lieu of the 7.62mm-caliber general-purpose machine gun (GPMG) down to the company level. The PLA grunts want to take their .50-caliber HMG and AGL with them all the time, even when they are on foot. The QJZ-89 breaks down to three major components for transport: the receiver, barrel and tripod. Each piece's carrying weight is no more than a typical GPMG. Reassembly takes only seconds with a trained gun crew. There are reports of long-term reliability and durability issues related to the QJZ-89 being too lightly built. However, the Chinese grunts are apparently willing to trade those drawbacks for the portability and tactical flexibility that the lightweight QJZ-89 HMG offers.
"Russian weapons may look crude, but they work- simple and durable enough for your typical farm boy conscript to use effectively." That was the most memorable comment I hear from the 3rd annual invitation-only Big 3 event during Mark Vorobiev's presentation. Vorobiev is a former Spetsnaz, the Russian Special Force, and veteran of the Soviet-Afghan War. His remark is very much the essence of all the Russian and Chinese .50-caliber HMG designs.