Can you screw the sizing die down any further into your press, or are you already (almost) touching the shell holder? I assume that - if you have a modern press that you are using a button shell-holder (my old Pacific Jr. has a dedicated shell-holder machined into the ram itself) so is there any chance it is for another caliber? Any chance your dies are mismarked? Do you know anyone else who loads for Krag with whom you can compare dies? In other words, can you shove your wrongly sized cases into another die, or do they hang up as with your rifle?