I think I've mentioned several times that during my 30+ years in Alaska I mostly carried a Ruger Super Blackhawk 44 Mag with hard casts. I can't remember how many know it all gun shop people explained that a double action gun was CRITICAL for bear protection and would begin clicking away with an empty gun. Well this video is PROOF positive a single action is just fine, and for proof they use a full 454 Freedom Arms, loaded with hot loads. 6 people shoot including Bryce Townsley and our own Max P. Since I don't know how to imbed I'll let you click on it. This is done by American Hunter.
https://www.youtube.com/watch?v=5F71SPRFr_Y#t=178
https://www.youtube.com/watch?v=5F71SPRFr_Y#t=178