I think the Federal slug (solid lead) I use is 547grains of weight.
And if you are hunting in close I guess the foot pounds of energy of a 12 gauge is equal to a 30-06.
I have seen black bear take a pounding. I've been using a Nosler 200 grain partition alot and at times we have sent that round lengthwise through the bear. Sometimes we got an exit wound and sometime not.
The only other thing I'd like to comment on which I have not seen on this post yet is the business about hitting a bear in the shoulders to "bust him up."
When me and my buddies started hunting bear we heard the above advice and my buddy listened to it. Well after wounding two and never finding them he finally concentrated on the lungs behind the shoulders.
I hope I'm not stepping on toes here about proper bullet placement. It's just what I've seen happen and occasionally I see posts about it. I just think your better off with a lung hit.
Strictly an opinion, and it's based on limited experience with black bear only.

Sausage blob being loaded onto ATV.
Used the 220 grain Sierra last year instead of the Noslers and left a nice thumb hole size exit on neck you should be able to see.
Head shots can bounce off though if the angle is just right. My buddy was in a ground blind with .44 mag and whistled to get it to stand up. He hit it between the eyes but only knocked it out. As he walked up to it it took off and of course the .44 had already been holstered. I'm sure it had a concussion.
It all depends on the angle, due to the slope on bears head. This link will show you a clean .44 mag hole in a bear skull, which cracked his head open too. I was standing 6' away and it was still alive as I approached it.
http://buckmountainchateau.com/images/bear_skull.tif