And as my daughter so thoughtfully pointed out to her moose hunter this past season - the 9.3x64 is "cute, sort of like a little sister to the .375 Ruger"
Phil, that's just how a woman would describe it.
A man would more accurately describe the 9.3X64 as the classy, sexy little sister to the 375 Ruger...the little sister who you pine for but makes your worry that she might just be out of your league.
I must also take issue with your previous singular anecdote of the gunmaker who couldn't get a X64 to run any fastEr than a X62. Given the difference in case capacities, it's a physical impossibility that the X64 can't achieve higher velocities absent some extraneous factor. My 9.3X64 pretty easily pushes a 286 grain TSX or Partition at 2675 fps...something the 9.3X62 can only dream of.
As to the original question, I believe a rifle meeting the criteria specified could be built in 9.3X62, 9.3X64, 375 Ruger or 375 H&H. The terminal performance differences between the four cartridges don't amount to much. The pertinent question is, how much effort are you willing to put into your relationship with your rifle?
