My choice is Bear spray, bear spray , bear spray
And then back it up with a 10mm in chest rig
The 10mm offers enough penetration and more speed compared to any revolver
Pistol skills are a very fast eroding skill if not kept up.
Train with a partner and timer to track progress , timer also adds some anxiety to mix . When you realize a bear is charging you , you will feel anxiety and the adrenaline pumping will limit your fine motor control . The timer helps simulate the same effects. Getting your body used to performing during that rush will help alot.
Your buddy is the competitor and you both will try harder to beat each others time and hit factor.
Bottom line, Carry what you can hit well with (train) , and what ever gives you a piece of mind