Dushka: The Soviet Fifty Caliber

November 16, 2009. Still soldiering on in NATO. A Romanian Army’s Spanish-manufactured Vamtac S3 HMMWV with a Dushka on top mount, being fired by an American soldier somewhere in Badabag Training Area, Romania. Note hammer within easy reach of the Romanian instructor crouching behind the shooter – this is an essential tool for disassembly and jam clearing on the Dushka. (Photo by Sgt. Marla R. Keown, Joint Task Force-East Public Affairs, US Army)

The world’s first real heavy machine gun appeared during World War I, although big-bore machine guns were by no means a novel feature by then – it was rather that the machine gun has retraced its own first uneasy steps.  The first ever machine guns, multi-barrel hand-cranked contraptions, were all of at least .45-inch caliber, as high as .58 – because those were the standard infantry rifle calibers of the era.  The first automatic machine gun designed by Maxim in 1882, was also chambered in .450.  It was only in the 1890s that the first machine guns were specifically built to fire smokeless ‘miniature’ calibers, being around .30-inch at that time.  The WWI resurrection of these big-bore cartridges came about because of the other two man-made wonders that appeared on the battlefield: the aircraft and the tank.

The first heavy machine guns were built in 1917 by the French, when it seems all of a sudden an idea dawned on them, that their conical-shaped, awkward Mle 1886 Lebel (8mm x 51R) rifle round owes that awkwardness to its direct parent, the Mle 1874 Gras round (11mm x 59R), its case being necked-down in 1886 and shortened to keep the overall length of the new cartridge.  If so, and if a Hotchkiss Mitrailleuse Mle 1914 was chambered for the Lebel, would it be then convertible to shoot the parent round? If so, the 11mm bullet would be an ideal vehicle to carry enough white phosphorus to put a fear of God into any airborne Hun!  The British also experimented with resurrecting the .450 Martini – and for the same reason.  Now that the Hotchkiss Balloon Gun was available, it was hurried into the air on board Voisin IX aircraft as an observer’s gun.  To employ it for single-seat fighters, it lacked on one significant point: firing from an open bolt, it was unfit for synchronization.  And so, in 1918 another Gras-round machine gun was created – this time using a Colt-manufactured Vickers M1915 converted to air use in 11mm, creating the Colt-Vickers M1918 “Balloon gun,” firing from the closed breech and thus eligible for synchronization.  Before the Armistice, the French, U.S. and Belgian air forces of the era roamed the skies in their Spads and Henriots with the 11mm machine guns, earning many kills with these.

But this was just for starters, as both the Hotchkiss and the Vickers 11mm guns were basically rifle-caliber machine guns, just chambered for a dusted-off antique large-bore ammunition.  The real break-through had been made in Germany, where fear of British tanks has spawned a machine gun chambered for the new, truly high-powered round, originally designed for a single-shot anti-tank rifle, the famous Mauser’s T-Gewehr: the 13mm x 92SR. Called TuF MG18, this Tank- und Fliegerabwehrmaschinengewehr Modell 1918 was the first of the new breed: true heavy machine guns, not only in bore diameter, but in power-level as well.  It was a Maxim machine gun, size-wise mid-range between the Grim Reaper (rifle-caliber MG 08) and the Pom-Pom (37mm automatic cannon of the Boer War fame).  Although barely fifty were manufactured before the war ended, this gun made a big splash: hardly any machine gun designing nation was able to resist an idea to build one for themselves in the interwar years.  Of these only two have achieved really lasting success and both are still encountered on battlefields in every corner of the earth: the Browning M2 and the Dushka.

The DShKM M1938/46 HMG of the Afghan National Army (ANA) on firing position in a fire base somewhere in the Hindukush Mountains. Note the round inserted into the cam operating lug to serve as the cocking handle in lieu of the damaged cocking handle on this M1938 Universal Mount.

HMG: The Soviet Style
The history of the DShK started in the hoary ages after the end of the Russian Civil War and the crushing defeat in the 1920 war by the Polish.  On October 27, 1925, the Revvoyensoviet (Military Revolutionary Council) of the RKKA (Rabochye-Krestyanskaya Krasnaya Armya, the Workers’ and Peasants’ Red Army) decided to develop new automatic weapons, chambered in calibers between 12 and 20mm.  Having reached that conclusion, the Revvoyensoviet ordered the Artkom GAU (Artillery Committee of the Main Artillery Directorate) to prepare the preliminary tactical and technical specification by May Day, 1927.  These called for a machine gun chambered in the British .5 Vickers (12.7mm x 81SR).  Tula Works designers, Ivan A. Pastukhov and Pavel P. Tretyakov were given the task.  The machine gun was to serve mainly an AA weapon, to counter the low-flying enemy aircraft.  It seems that the painful lesson taught by American ‘mercenary’ pilots (including Lt. Merian C. Cooper, later to became a Hollywood producer of the first King Kong movie) fighting for the Polish was well learnt.  Ground role, like anti-tank duties, was deemed secondary.  The Vickers round promised an opportunity to follow the British success in creating another blown-up Maxim gun.  However, in 1926 the Italian, who also adopted the Vickers ammunition, indicated another path, by designing an entirely new gun, called the Breda-SAFAT, which after arduous labor and troubled childhood has developed handsomely into a very successful aerial HMG.

The Artkom decided to emulate the Italian example rather than go the Vickers path as initially planned.  The gun experts at GAU calculated that the Model 1910 Maxim enlarged to handle the .50-caliber round would weigh a minimum of 60 kg (132 lbs) – and that without a mount.  This was deemed intolerable for a modern weapon and designers were instructed to abandon the Maxim system.  Another problem was the water-jacket.  In a primarily AA weapon, the inertia of the water sloshing in a large pipe surrounding the barrel would get in the way of the gunner’s ability to precisely lead the flying aircraft, except for on a complicated cogwheel-operated mount.  The Artkom specification thus called for air-cooling.

The Tula team faced a difficult challenge – they had precious little experience outside the Maxim platform, and they were working in an internationally-isolated country.  Browsing through the captured materiel they decided the Dreyse M1910 machine gun would be the best way to go, its tilting-lock breech being much simpler than the Maxim or Browning.  Before they realized it was a dead-end, it was already too late to start from scratch.  The resulting weapon was a recoil-operated, closed-bolt firing weapon, with a low rate of fire – but high rate of stoppages.

JS-2 heavy tanks were the first that rated individual anti-aircraft defense by way of the Dushka mounted on a special ring mount with spring equalizers to relieve the weight and enable one-man handling. The relaxed stance of the soldiers on the engine compartment cover suggests that the tank’s loader is fighting mainly his boredom in captured Berlin.

The same specification was also independently taken on by Kovrov-based designer then rising to meteoric fame – Vasiliy A. Dyegtyarov (NB – even though all sources spell his name as Degtarev, because of the 1:1 transliteration from Cyrillic alphabet, this name in Russian is actually pronounced as ‘Dyegtyarov’).  Dyegtyarov was a self-educated ex-metal worker, mentored by the leading Soviet small-arms authority, the ex-Tsarist general, Vladimir G. Fyodorov (another victim of misspelling, he is known in the West as Fedorov), a designer of the world’s first assault gun, the M1916 Avtomat Fyodorova.  His pupil was possessed by his idea of a ‘machine gun system’ – a universal machine gun design, with the same lock-work and operating principle, adaptable to become almost every machine gun ever needed by the military.  In 1927 he was in the midst of revolutionizing the Red Army’s armament by introducing his trio of same action rifle-caliber gas-operated machine guns: the DP for the infantry, the DT for armor and DA for the air force.  Just as the 1917 recoil-operated Browning almost immediately spawned the field, tank and aerial versions, so did Dyegtyarov.  And where Browning’s next step was a scaled-up Fifty – so was Dyegtyarov’s.  He was, however, not bonded by the Artkom’s decision to use the British round, and so he decided to use a completely different, much more powerful cartridge, the 12.7mm x 108, being developed by the Soviet ammunition industry at that time.  This ammunition was initially designed and manufactured in two sibling versions: one rimless, and one rimmed (12.7mm x 108R), the latter adopted for the early version of the ShVAK aerial machine gun, better known in its final form of an automatic cannon, chambered for the 20mm x 99R ShVAK round of the same outside diameter and overall length.  Both of the 12.7s were identical, except for the lower extremity of the cartridge case.

In 1929, four years after the Revvoyensoviet decree, the Red Army still had no heavy machine gun, and after large summer maneuvers the narkom (People’s Commissar, or minister/secretary) of Military and Naval Affairs Kliment Ye.  Voroshilov grew impatient.  He summoned both teams to stress the importance of their task and urged them to hurry-up, reportedly using his trademark ‘military non-uncertain terms.’  As a result of this meeting, Dyegtyarov’s gun was given an official development sanction (it was hitherto developed as an experimental, almost-private venue), and hurriedly introduced into the inventory of the Red Army as the “Dyegtyarova Krupnokalibyerniy” (Dyegtyarov’s Heavy) or DK.  In a nutshell it was a gas-operated, flap-locked open-bolt firing DP LMG on steroids, chambered for the new 12.7mm round.  At first it was even fed from the same style top-attached pannier magazine, but the size and weight of it proved prohibitive, and so in 1931 a new drum magazine was designed for it by Alexander S. Kladov.

This magazine, as well as the whole feeding mechanism, proved to be a soft underbelly of the DK.  The theoretical rate of fire was less than impressive at 360 rpm, and the resulting practical rate of fire was low as well – or worse, as the gun jammed almost constantly.