If I have to use my weapon, I don't want to piss the bad guy off, I want to kill him.
I follow Clint Smith's advice: .45acp (ball) in a 1911 style weapon. Proven performance over a very wide range of variables.
Will frangible ammo reliably penetrate even a heavy leather jacket and still deliver real stopping power afterwards? I won't bet my life that it will.
Police experience with 4 Buck in a 12 gauge has found it won't even reliably penetrate leather jackets. (That's why police departments overwhelmingly choose 00 Buck instead.) Anyone want to bet their life that Glasers or MagSafe will do better?