The real short barrel pistols have issues. You're losing velocity, if you go to lighter bullets to try to get the velocity back, you're losing sectional density/penetration.

Lobo's got an excellent point about the sights. Cor-Bons got a 230 gr JHP load that should provide decent penetraton and might still expand. I expect their 185 gr DPX would do very well, but you're into the POA/POI issue again, plus it's pricy. I wouldn't carry hardball.