IN warmer months my mags are only loaded with Winchester Ranger 230gr +P hollow points.
In colder months, where extra clothes may slow penetration through layers I alternate the Winchester and 230gr +P ball ammo. If the hollow point can't get to the meet, then ball will make a nice hole and soften the target up for the follow up HP.
I also follow Rob Pincus' Combat Focus shooting plan: Keep shooting to end the threat, so chances are good one mag might be empty, or almost empty, by the time the bad guy goes down, so I carry one in the gun and two spares.
JD