Franz Gebauer

Biography

Gebauer was born in 1888 in Gross-Herlitz, Austria. After finishing his schooling, he worked for a German car manufacturer, and later for Puch in Graz.

During World War I, he served in the Austro-Hungarian Air Force as a Waffenmeister at the Fischamend Military Airport.

Gebauer became a member of Danuvia RT's board of directors in 1926 and Technical Director in 1937. He fled to Sweden when the Soviets invaded Hungary in February 1945, where he worked for Bofors. He died in 1958.

Weapon designs

During World War I the Schwarzlose MG M.07/12 was the standard machine gun for aircraft use. It was internally modified and air cooled to increase its firing rate to 700 rounds per minute, and normal practice was to use a pair of synchronized guns. However, although the Schwarzlose was an excellent infantry weapon on the ground, its use in aircraft had problems; at altitudes approaching 4,000 m (13,000 ft) the cartridge oiling system tended to freeze up, causing many failures during combat.

Gebauer concluded that the then-common practice of converting infantry machine guns for aircraft use was outdated. The most common problem with such converted weapons was that the position of the aircraft's propeller controlled the time of firing only, with the rest of the gun's operation depending on the force of propellant gases; a late-firing cartridge could cause damage to the propeller blades, while misfires stopped operation altogether. Gebauer had the idea to directly power a machine gun from the aircraft's engine, independently of the gas produced by the gun's cartridges. This meant that misfired cartridges would be automatically ejected and the next loaded. He called it the direct-driven motor machine gun.

Gebauer Machine Gun 1918.M

In 1917 Gebauer submitted his first twin-barreled motor-driven machine gun design to his commanding officer and received approval to make prototypes. The first two were not successful, but the third improved design performed flawlessly on its trial in June 1918 at Aspern, near Vienna. The prototype was installed on an Aviatik D.II aircraft, flown by Colonel Benno Fiala.

The Gebauer 1918.M (Gebauer Motorgéppuska 1918.M) weighed 21 kg (46 lb) and could fire at a rate of 25 rounds per second, or 1500 rounds per minute, 4 times faster than the Schwarzlose, which could only achieve 6.25 rounds per second in similar conditions. The first 100 guns were ordered by the military in September 1918, the Solux Company of Vienna providing additional monetary support. The 100 guns were completed in October 1918, but the Armistice prevented actual combat testing.

Gebauer Machine Gun 1926/31.M

After the end of World War I, Gebauer lived in Budapest, Hungary. In 1920 he worked unofficially for the Technical Experimental Weapon Division of the Hungarian Army, receiving funding from the military to continue improving his machine gun design in secret from Allied inspectors.

In 1922 a final prototype was created and designated 22.M GMP (Gebauer Motor Puska). From 1924 Gebauer started to work with the company Danuvia RT; the cooperation was to last for the next 20 years, Danuvia taking over funding and marketing. Gebauer became a member of Danuvia's board of directors in 1926 and Technical Director in 1937.

In 1926 Gebauer's latest improved model was approved by the Hungarian military, and manufacturing began. Between 1926 and 1934 243 guns were delivered to the Hungarian Air Force. The Air Force machine guns were designated 26/31.M GKM (Gebauer Kényszermeghajtású Motorgéppuska, or "Gebauer Positive-Driven Motor-Machine Gun"); they were fixed twin-barrel guns driven from the aircraft engine's crankshaft. The GKM's drive had an automatic safety feature which disengaged a jammed barrel, while keeping its twin in operation. The guns were fed by 500-round belts and were chambered for the 7.92×57mm Mauser cartridge.

The GKM was used until 1942 on the Fiat CR-32 fighter, the IMAM Ro.37, the Heinkel He 46, and the WM-21 Solyom.

Gebauer GKM Machine Gun 1940.M

This weapon was the same as the 1926/31.M, except it used the 12.7mm Italian Fiat-Safat cartridge. The gun was adopted in 1940 and was used on the Fiat CR-42 fighters which were supplied to Hungary by Italy in 1941-42. In 1943 Italy obtained a license to manufacture Gebauer machine guns in return for two Italian fighter planes, but it is unknown whether the Italians ever manufactured any Gebauers.

Gebauer Reconnaissance Machine Gun 1934.M

This was a conventional gas-operated air-cooled machine gun with a fixed barrel, designed for use on reconnaissance aircraft. The gun was fed from a 100-round "Horvath" drum magazine and was chambered for the 7.92×57mm Mauser cartridge. It saw service from 1934 to 1942 in the Hungarian Air Force. Operation and maintenance was much simpler than the earlier Schwarzlose machine guns.

Gebauer Tank Machine Gun 1934/37.M

This gun (also called the 34.AM) was essentially identical to the 34.M, but was slightly modified for tank use, though retaining the 100-round drum magazine. It was chambered for the 8×56mmR 31.M cartridge. It was used in both single and twin mounts in the Fiat-Ansaldo M13/40 light tanks, Csaba armored vehicles, and Toldi light tanks. From 1942 it also saw use on gunboats and patrol boats, being used for airdefense and fitted with large round anti-aircraft sights.

Gebauer Tank Machine Gun 1934/40.M

This gun was the same as the 34/37.M, but the drum magazine was replaced with a 100-round metal belt and a 41.M sight was fitted. These guns were used in the 40 M Turan I tanks and by the Flotilla for air defense. All captured Gebauer guns that were still serviceable were taken back to the USSR following the end of World War II.

Gebauer Semi-automatic rifle

Existed only as prototype. Although it was a very good design and operated smoothly, it was turned down by the army officials, so that the soldiers would not waste ammunition by firing them too fast.