Hoot4570,
9.3x57R or 9.3x57R/360 are German designations for the English 360- 2 1/4". Just like the other old 9.3s, this cartridge shows variation in groove diameters and German guns may show "D" version or "E" version chambers, causing confusion IDing pre 1912 nominal caliber designations. BTW, there is no similarity in ballistics between the 9.3x57, popular in Sweden, and the 9.3x57R, under discussion here and only case length is the same, not head size
Mike.