“But bear spray MIGHT BE 90% effective in stopping a bear attack.”
A gun may only be 50% effective. My understanding is their CNS must be completely destroyed to get them to instantly keel over. I’ve read where they will run an additional 100 yards or worse yet kill the shooter after their heart was blown out.
My opinion is to shoot first, spray later if it keeps on coming. At least you can reassure yourself you tried everything while being mauled to death.
The CNS advice is correct. Not easy on a charging bear, recall how their head swings right to left. It's a deadly situation to be in at close range.
Anecdotal, and I've no way of knowing if true, but I was told of a fishing guide who was attacked and put 4 rounds of .44 mag in the body with no immediate effect. The attack was halted by another guide who sprayed the bear. Who ran off and died. Would he have stopped if sprayed first, who knows. I prefer to avoid bears.