X2 on wierdo ,s post. Shoot with what you feel confortable with. Instant target acquisition is most important up close. It is not self defense if the bear is a hundred yards away and walking away.
Do your research on buck shot effectivness. Traditional thinking in a shot gun is slug then buck shot. I disagree. Two inches of fur and hide then one to five inchs or more of fat then there is bone , it has lost its effectiveness. No. 7 1/2 shot for warning. Save those for home use. Slugs all the way for me. Practise at the range and know your firearm and how it handles and swings.
And yes I have only shot one black bear in my tent. You have no time to think or react when bears happen.