Schwarzlose MG M.07/12

Oesterreichische Waffenfabriks-Gesellschaft (Steyr) · Machine Gun · Out Of Production · 1912

Also known as: MG M.07/12, Schwarzlose M.07/12, Maschinengewehr Schwarzlose, Kulspruta m/14, Schwarzlose M.08 (Dutch), tezky kulomet vz. 7/24, 7/31M Schwarzlose (Hungarian)

Overview

The Schwarzlose Maschinengewehr M.07/12 was the standard heavy machine gun of the Austro-Hungarian Imperial and Royal Army throughout the First World War and the principal HMG of several smaller European powers well into the Second World War. Designed by German engineer Andreas Wilhelm Schwarzlose and manufactured by Oesterreichische Waffenfabriks-Gesellschaft (Steyr) beginning in 1905, the gun is notable as one of the very few successful retarded-blowback heavy machine guns ever fielded. Rather than the long-recoil or gas-operated actions favoured by contemporaries such as the Maxim, Vickers, and Hotchkiss, the Schwarzlose uses a toggle-delayed (retarded) blowback mechanism in which a jointed toggle arm and a heavy recoiling breech block combine to hold the cartridge in the chamber long enough for chamber pressure to drop to safe levels. Because this arrangement cannot safely dwell as long as a locked action, the designer was forced to fit an unusually short 526 mm (~21 inch) barrel, which gave the gun a distinctive stubby silhouette and a muzzle velocity of roughly 620 m/s with the original 8x50mmR Mannlicher cartridge - noticeably lower than Maxim or Vickers contemporaries firing the same class of round. To ensure reliable extraction despite the still-dirty residual pressure at the moment of unlocking, the gun incorporated a small oil reservoir and pump mounted atop the receiver that squirted lubricant onto each cartridge as it was chambered; operators had to keep the oiler topped up and regularly clean the accumulated oil-and-fouling residue from the action. The M.07 entered Austro-Hungarian service in 1907, with the strengthened M.07/12 pattern (heavier recoil booster, improved toggle geometry) becoming the definitive wartime model. It was fed from a 250-round fabric belt at a cyclic rate of roughly 400-450 rounds per minute, cooled by a water-filled jacket around the barrel, and fired from a substantial tripod using spade grips and a rear thumb trigger. Over 40,000 guns were built during the war, and post-Armistice reparations scattered Schwarzlose machine guns across Czechoslovakia, Italy, Yugoslavia, Romania, Poland, and Hungary. The Dutch, Swedes, Greeks, and Bulgarians had all been pre-war export customers and continued to use their Schwarzloses through the interwar period, with the Royal Netherlands Army still fielding them against the German invasion of May 1940 and the KNIL using them in the Dutch East Indies against Japan in 1942. Sweden's Kulspruta m/14, rechambered in a domestic 6.5x55mm and later 7.92x61mm load, remained a standard Swedish fortification and training gun into the 1960s. For all its mechanical oddities the Schwarzlose proved dependable, easy to manufacture (roughly half the part count of a contemporary Maxim), and well-liked by its crews.

Specifications

Weight (empty)19900 g (702.0 oz)
Overall Length1070 mm (42.13")
Barrel Length526 mm (20.71")
Action TypeBlowback
Firing MechanismHammer Fired
Trigger TypeSingle Stage
Magazine Capacity250 rounds
Magazine TypeBelt
Muzzle Velocity620 m/s (2034 fps)
Muzzle Energy3036 J (2239 ft·lbf)
Effective Range2000 m (2187 yd)
Maximum Range3600 m (3937 yd)
Rate of Fire425 rpm
Barrel RiflingRight Hand
Number of Grooves4
Frame MaterialSteel
Barrel MaterialSteel
FinishBlued

Calibers

Features

Variants

Service history

Operators

Conflicts

Production

Estimated total produced: 45,000 · Production years: 1905-1918

Approximately 40,000-50,000 guns produced by Oesterreichische Waffenfabriks-Gesellschaft (Steyr) during the main production run, with the bulk built during 1914-1918 wartime expansion. Additional licensed production in the Netherlands (Hembrug) and Sweden (Carl Gustafs stads gevarsfaktori) added several thousand more guns, and interwar Swedish m/14 production continued into the 1930s. Small quantities were also assembled from parts at Skoda in Czechoslovakia after the breakup of Austria-Hungary.

Origin

Country of origin: Austria

Designer: Andreas Wilhelm Schwarzlose

Discontinued: 1918

Notes

The toggle-delayed blowback action is mapped to the closest schema enum value 'blowback' - strictly speaking the Schwarzlose is a retarded or delayed blowback design, relying on mechanical disadvantage from a toggle linkage plus breech-block inertia rather than a true locked breech. The short 526 mm barrel is a direct consequence of the action: the breech cannot unlock until residual pressure has dropped, so a longer barrel would allow the bullet to exit before the toggle began to collapse, wasting energy and causing feeding problems. The oil-injection system on top of the action is the gun's most widely criticised feature - oil had to be kept clean and free of grit, cold weather thickened it, and dust adhered to the oiled rounds - but in practice Austro-Hungarian gunners mastered its foibles and rated the gun highly. Rate of fire figures vary by source and pattern: the M.07 cycled around 400 rpm, the strengthened M.07/12 around 425 rpm, and the late-war M.07/16 pattern (with a lightened breech block and tuned recoil spring) approached 580 rpm. Many interwar users rechambered their Schwarzloses in domestic cartridges - Hungarians and Austrians converted to 8x56mmR in the 1930s, Italians to 6.5x52mm Carcano for some captured guns, Czechoslovakia retained 8x50mmR and issued the gun as the vz. 7/24. The Swedish m/14-29 conversion moved the gun from 6.5x55mm to 8x63mm patron m/32 for longer range and heavier fire. The gun is usually mounted on the M.07 or M.12 tripod and operated via twin spade grips and a thumb-lever trigger, with iron sights graduated to 2400 metres.

Background

The Schwarzlose's squat silhouette and oil reservoir made it the butt of jokes among Entente observers - 'the machine gun that needs a salad bar' - but its Austro-Hungarian crews loved it. The toggle-delayed blowback action had fewer parts and was cheaper to manufacture than a Maxim, yet was so unusually robust that the Dutch fired theirs at invading Luftwaffe bombers in May 1940, more than three decades after first buying the design from Steyr, and Swedish coastal bunkers kept oiled Schwarzloses on standby into the Cold War.