I have a 9.3x57 rifle built on a 1909 Argentine action. I made up some cartridges using Norma brass and PP 285 SP bullets, and test fired them on Saturday. The load is mild and seems to be accurate, but there is a problem: the case neck expands enough to engulf a .375 bullet! I believe the rifle is chambered for a 9.5x56, but has a 9.3mm bore. I don't happen to have a 9.5x56 cartridge to try, so I don't know for a fact whether it would chamber. Has anyone else run into something like this?