Let's say a handgun manufacturer like Freedom Arms, Ruger, Smith and Wesson, or Magnum Research approached you and asked for your input on a new cartridge for a new hunting revolver or semi-auto. You look at the selection of cartridges already available, such as the 357, 10mm, 41, 44, 454, 480, 475, 460, and the 50's. What would you tell them? Would you ask them to design a relatively small bore, high velocity cartridge? Or perhaps a big 50 caliber that runs at moderate pressure? Maybe you'd want a compact cartridge for a more compact gun. Heck, you might even create a bottleneck cartridge like the 357-44 B&D. Keep in mind it would be purely a hunting handgun, not something you would want for self-defense.
What kind of cartridge would you like to see come to fruition?