R.Marshall,
I have come to the painful conclusion that I don't know what the heck it is chambered for now. It seems to have been chambered for a standard early German cartridge and underwent some unfortunate attempt at rechambering to something that was available, and is now unidentifiable. If it were mine, I would fireform a couple more 6.5x55 Norma cases, "slug" the barrel to insure it is 6.5mm(.264" about) and send the fireformed cases to CH4D to have them make a set of dies to fit the chamber. Then you can treat it like a wildcat, load to 6.5x57 pressures, call it whatever suits you( 6.5 Marshall special?) and kill a pickup truck load of deer with it.
Mike
