It's easier to stop the bleeding from one big hole than multiple smaller holes. All bullets kill whether they're FMJ or JHP. They still kill. When a firefight ensues a lot of lead gets thrown and even with the best training, the best shooters miss. At that point in time it's an odds game and I'll take the odds of 30 rounds thrown as opposed to 21 rounds. I prefer to carry 9mm for that reason.