Have you ever spooked a bear in the wild. They are quick and fast. Their reaction time is scary fast. You have one charge you, you will not have time to empty a magazine and you will be pointing at a black bundle of fur with fangs. Hunt with a slow friend. You probably won't stop a charge with a 9MM. It may bleed to death, or wonder off and die. But that won't be very soon.
A 12g pump or semi auto with slugs or really heavy buckshot. You want something that points naturally and throws some weight.