Just a question: Why would you be so concerned about needing to protect yourself from a black bear? I've spent a lot of time in black bear country and have never had one act in the lest bit aggressive towards me. Every one I've seen has wanted to put as much ground between me and it as quickly as possible. Taking simple precautions pretty much negates the possibility of having any sort of bear issue in the first place.

The biggest question in my book when someone asks about a handgun for bear protections is just how good are you with a handgun in a high stress situation? Most people simply don't shoot enough in those types of conditions to reliably use a handgun. A 12 ga pump with a the plug removed and a short barrel loaded with 00 Buck makes more sense to me.

Now to the question: Will a 45 ACp kill a bear? Yep. Is it a good choice? In my humble opinion, NO, especially with the ammo you're listing. If you need to stop an angry bear you need to do as much damage as possible and that means expanding ammo. If I wanted a handgun for bear defense I'd use a .44 Mag and I'd learn how to shoot it well.