Otto Eberhardt Patronenfabrik (English: "Otto Eberhardt Cartridge Factory") was a munitions company established in 1860. The company's Hirtenberger Patronen, Zündhütchen und Metallwarenfabrik (English: "cartridge, primer and metalware fabrication in Hirtenberg") near Wiener Neustadt (proofmark "am")[1] used forced labor during World War II from a sub-camp of the Mauthausen-Gusen concentration camp and produced ammunition including 9×19mm Parabellum (pistol and submachine gun) and 8 mm Mauser (rifle) cartridges. The company also had a factory in Ronsdorf near Wuppertal (proofmark "ap")[1] which produced rifles. Additional Gustloff facilities were in Meiningen[1] and Weimar.[2]