I am trying to identify the correct cartridge for a Austrian double rifle.
Proof marks - Frelach Austria - 1892 to 1918.
12.8 on the bottom of both barrels
No nitro proofs and the rifling has no sharp corners.
That tells me we are looking for a 50 caliber / 12.8 mm black powder sporting shell used around the turn of the century.
To the casting. Some variance depending on where I measure them, my numbers could be off 0.2 mm or so.
Bore diameter 0.508 inches (12.8 mm)
Chamber length to rifling (no free bore) about 2.4 inches (63 mm)
Rim diameter, about 0.65 inches, (16.5 mm)
Diameter adjacent rim 0.58 inches (14.7 mm)
Dia at end of chamber 0.53 inches (13.5 mm)
Chamber has slightly steeper taper in in the first 1/2 inch by the head of case and then an even shallow taper to the case mouth.
I have looked at the DMG book and I suspect a 500 BPE in 2 or 2 1/4 in.
I see from other posts, there were several forms of the BPE depending the country of origin, but would suspect a continental variant given the country of origin.
Are their other possibilities I should be considering?
Can anyone provide photographs, drawings, images or other information on either cartridge from any country? Even catalog descriptions could be useful to me.