Is this the 12.2X44R or similar - ie: Swedish version of a .50/70 Husky RB? Most were stamped around 1874 through 1884. I suspect the 8x57R or 8x56R, ro 8x58R, or whatever they were, are 1890's rifles and are nitro proofed but I suspect they'd be OK for up to maybe 35,000cup - just a guess, mind you. Most info is needed. The Swede's had a rimmed ctg. that was quite tapered, low capacity and low pressure in an 8 mm., seems to me - might have been the 8x58R. Memories on some things are a fleeting source of info. www.shop.tradeexcanada.com usually has them for sale as well.