Pardon my repetition, but I'll share a personal story. Understanding that the .40 cal was developed in response to complaints surrounding the 9mm, many LE agencies have made the jump including my son's department. He was involved in a fatal PAS where he fired 5 times
point blank at center mass with Federal JHP's, and the suspect still had to be pulled off of my son. In perspective, my son had been on a homicide call a week earlier where a man killed his neighbor with a .25 auto at 20 feet, and dropped him like a sack of hammers with 2 shots. Nothing is etched in stone and in my later years I have stowed my "go big or go home" speech.