Standschütze Hellriegel 1915 (German: Maschinengewehr des Standschützen Hellriegel, "Machine gun of Standschütze Hellriegel") was an Austro-Hungarian water-cooled submachine gun produced during World War I in very limited prototype numbers.
History
Little is known about the Standschütze Hellriegel Model 1915. The only source of information about the Hellriegel is several photographs stored in the photo archive of the Austrian National Library under the name “Maschinengewehr des Standschützen Hellriegel” (literally "Machine gun from reservist Hellriegel"). The photographs are dated October 1915 and they show the weapon being tested at a firing range. Its name and magazine size indicate that it was an automatic firearm, and its designer was someone named Hellriegel from the Austrian militia unit Standschützen, tasked with the defence of Tyrol and Vorarlberg regions of western Austria, the former bordered "neutral" Italy. It was most likely a prototype and therefore explains its "unfinished" look and design.
The development of this weapon coincided with the Italian entry into World War I on the side of the Entente, and its subsequent declaration of war on Austria-Hungary - its former ally in the Triple Alliance - which forced the Austro-Hungarian Empire to wage war on three fronts. It is possible that the idea of the weapon came from the frontlines, possibly from a senior officer, and the production of the prototype was carried out in a field workshop or in a small warehouse. However, it is also possible that it was created in the rear through someone else's own initiative. The Standschütze Hellriegel did not pass the prototype and testing stage and was forgotten. It is likely that only one weapon was produced and it was scrapped or disassembled.
According to army tradition, weapons are usually named in honour of their creator, the creator of this weapon was a man by the name of Hellriegel, who was possibly an officer or someone more junior in rank. The man in the photographs who was testing the weapon holds the rank of Feldwebel. Waffenmeister I. Klasse (literally "Field usher. Weapon master 1st class"), a rank for non-commissioned officers responsible for an artillery or weapon arsenal.
It possible the man photographed is Hellriegel himself, although unlikely. The only known Standschütze volunteer of that name was Dr. Richard von Hellriegel, the medical officer of Standschützen-Bataillon Kitzbühel. Other soldiers bearing the Hellriegel surname are served in the Kaiserjäger but none of them can be definitively linked to this weapon.
It is possible that this was the first-ever conventional submachine gun design to be tested, by this point, the Italians already had the 'Villar Perosa' submachine gun, though it was designed to be fired from a mount. The Hellriegel is certainly the first known submachine gun to have been designed with a buttstock, and therefore intended to be fired from the shoulder. The military theory behind the Standschütze Hellriegel's creation was likely similar to that of early light machine guns such as the Chauchat and Browning Automatic Rifle; A light machine gun that could be carried by troops, used in infantry assaults, and capable of suppressive fire.
Design
Hellriegel's submachine gun was a fully automatic firearm. The gun had a water-cooled barrel. The cooling-jacket around the barrel bears similarities to that of the Schwarzlose machine gun, and had two openings, one to fill it with water and the other to release excess steam. It was covered with leather so it could be handled even after sustained firing. A bent tube was fixed under the barrel, which was used as a foregrip. The stock of the gun appears to be a modified version of the Mannlicher M1895 rifle stock, with a deeper cut thumb-groove.
Details about the internal operation of the firearm are not known. It appears to be blowback-operated, judging by its two coil springs which protruded behind the gun's cylindrical receiver. An iron sight was mounted on top of the receiver, with the rear sight appearing to be adjustable for range. According to rough estimates, the rate of fire of the gun could be about 550-650 rounds per minute. Although during actual combat the actual sustained fire rate would most likely be much lower.
Ammunition
Hellriegel's submachine gun may have fired the 9×23mm Steyr cartridge, which was the service pistol ammunition for most branches of the Austro-Hungarian military during World War I. Alternatively it may have been chambered for .32 ACP, which was used in the Hungarian Frommer Stop pistol. However, the cartridges shown in the photographs also resemble the 8mm Roth–Steyr cartridge used by the Repetierpistole M.1907.