Hmmm... I have a Krieghoff drilling made in the mid 1930s in .318 as well (marked 7,7 / 57). When I acquired it, the previous owner graciously include 2 boxes of 8x57JS (.323) but mentioned that he only fired 3 rounds through it for test and was not thrilled with it. It shoots very accurately and is rather pleasantly with S&B JR rounds.