The Standschütze Hellriegel 1915 was an early 20th century prototype Austro-Hungarian water-cooled submachine gun. Although the term "submachine gun" had not yet been coined in 1915, the Standschütze Hellriegel is an example of a "heavy submachine gun", which is a submachine gun intended for a support role. This is supported by it being referred to as a "Maschinengewehr" on its three photographs, which means "Machine Gun" in German.
An extremely obscure weapon, no surviving examples are known to exist today but at least one prototype was known to have been made.
All information relating to the weapon exist as conjecture based on three photographs found in the Austrian National Library, captioned Maschinengewehr des Standschützen Hellriegel and dated 10.1915, depicting what appears to be Austrian soldiers testing a prototype of the weapon.
Most of the background information regarding the weapon is unknown, but some information can be speculated from its name. "Standschütze" refers to the Austrian-Hungarian reserve forces, the Standschützen, while "Hellriegel" is an Austrian surname. Firearm naming conventions imply that the weapon is designed by an Austrian designer named Hellriegel, while "Standschütze" implies that the designer is either designing the weapon for the Standschützen or is a member of it.
The dating on the existing photographic evidence suggests that the weapon prototype was developed around October 1915 or earlier.
The weapon appears to not have progressed beyond the prototype stage. It is likely that the photographed example is the sole example of the weapon to ever be made.
Like its history, its design details are largely unknown and can only be inferred from its three images. It is chambered for what is likely 9×23mm Steyr, the pistol round used by Austria-Hungary, though some sources speculated that other calibers such as the .32 ACP (used on the Hungarian Frommer Stop pistol) are also possible.
It is fed from either a drum magazine or a stick magazine (of which there appears to have been two types tested). Their capacities are estimated to be around 160 rounds and 20 rounds respectively.
Contrary to popular belief, the weapon is not belt-fed; the spring-tensioned drum magazine (similar in design to the TM 08 used on the Luger P08 and the MP 18) was connected to the weapon by means of a segmented, flexible chute, which would be rested on the ground like a belt box using a weighted base.
The barrel was fitted with a water cooling jacket, similar to the MG 08. It has a pair of ports to fill and drain the water. A small tube-shaped object underneath the barrel is believed to be a small foregrip.
The operation of the weapon is uncertain. It likely uses blowback action, and the two prongs protruding from the rear of the receiver suggests that it had dual recoil springs.
The weapon has a folding ladder sight on top of the receiver.
- The Standschütze Hellriegel 1915 is notable for appearing in the video game set in World War I, Battlefield 1, depicted with a fictional drum magazine attached to the weapon. Since only images of the right side of the weapon exist, the left side had to be modelled with no reference.