This is NOT to start a caliber war but to search out opinions. This was a local incident early this week where an auxillary police officer fired his pistol twice in defense... read the article and towards the end is the description of where both bullets ended up. I have been unable to find what caliber was being used but it sure makes a point about having enough gun.
"Creve Coeur - Seated in his truck at the Northwoods Mall parking lot Monday night, Chad R. Hjortshoj thought he heard what sounded like a scream. After opening his door, the muffled noise became clearer - a woman's voice yelling for help."
Entire story at: