I recently purchased a Stützen that ended up being chambered in a completely different caliber than advertised. While waiting for proper chamber casting material to arrive I made a wax cast of the chamber today. It appears to be a 10.75x61mm Haenel, DWM case number 523. I’m hoping to get any more possible information on the development or use of this cartridge. I’ve dug around and have yet to find another rifle mentioned in this caliber, if you know of any I would love to compare notes.