The key question is Blacks? or Grizzlys?
Most black bears are killed with deer rifles or slug shotguns.
Personally, if I were to go on a black bear hunt, like at IceQueens
I'd take a rifle I use for whitetails, and not worry about it.
I would use a bit stronger bullet than I might for whitetails, tho. Like a Nosler Partition, Winchester Fail Safe, or Barnes X.
I hope IceQueen sees this thread and answers- she's seen more black bears killed than any of us, I think.