The Standschütze Hellriegel 1915 was a prototype Austro-Hungarian water-cooled submachine gun chambered for what is likely 9×23mm Steyr rounds. An extremely obscure weapon, no surviving examples are known to exist today but at least one prototype was known to be 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.
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 implies that the prototype of the weapon was developed around October 1915 or earlier.
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.
Contrary to popular belief, the weapon is not belt-fed; the drum magazine was connected to the weapon by means of a flexible chute, which would be rested on the ground like a belt box using a weighted base. The 160-round drum was spring-tensioned, and the weapon can also use 20-round stick magazines. The barrel was also fitted with a water cooling jacket.
- 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.