Weapons of AustraliaGo Back to Countries Go Back To Weapons Home Submachine GunAusten Submachine GunAn Australian submachine gun developed during World War II as an alternative to the British Sten gun. Chambered in 9x19mm Parabellum, it combined features of the Sten and the German MP40.Owen Submachine GunAn Australian submachine gun renowned for its reliability in harsh conditions during World War II. Chambered in 9x19mm Parabellum, it featured a top-mounted magazine and simple blowback operation.