Based on real world bear attacks, you don’t aim for the brain. Odds of killing the bear aren’t all that great anyways. But even a 9mm has an excellent record of getting bears to break off an attack.
Maybe the unfamiliar noise or maybe the unexpected sharp pain in a muscle? Don’t know, but getting a HIT in on the bear is probably more important than trying to get a brain shot.
I have read every thing Dean Weingarten has written on the subject of bears. There are far too many cases where the bear kept attacking after being shot more than once.
There are stories of bears shot, continuing the charge and dropping dead on the shooter as well as at the shooter’s feet....indicating that the bar came very close to living long enough to harm the shooter.
There is also a story complete with photos on Buffalo Bore’s web site of a grisly killed with a 9mm loaded with hard cast flat nosed. The bear soaked up 13 (I think) bullets before dropping a few feet from the guide.
Obviously not everyone can hit the brain of a charging bear, but I do suggest that they try.
Bear attacks vary considerably. Many attacks have been stopped with brain shots, even of large, charging, grizzly bears at close range.
Some attacks have been stopped when the victim pushes the pistol into bears mouth and pulls the trigger.
The real world is complex. No one solution fits all problems.
In collecting all documented cases where a pistol was fired in defense against a bear or bears, the attack was stopped in 98% of the cases.
In many cases, aiming for the brain is the optimum solution.
In others, body shots have worked.
In others, warning shots have worked.
“...you don’t aim for the brain...”
If you’re using a shotgun and they are going to be that close, then aim for the front legs which will include the muzzle. At that close a range you would have to be lucky to kill them but if you can inflict pain and surprise, you might scare them to run. And blinding them or knocking them down momentarily by taking the legs out will give you a chance to withdraw backing away. It is a shotgun so do your best to cover the animal with projectiles.
wy69