For years this cartridge has sat in my cabinet identified as the 11mm M.67/73 Werndl Carbine. But then I compared an 11mm Fruhwirth Carbine cartridge to it and realised that the bullet diameter is larger. The bullet actually measures 12.2mm. The Werndl Carbine should also have a caselength of about 42mm and my round has a caselength of 43.9mm.
I’m probably missing the obvious but if it’s not an 11mm Werndl Carbine cartridge what is it?