1. a .44 mag isn't really enough for a grizzly - but requires less luck than say a .38
Black bears are less likely to attack, and while presence of cubs is the greatest danger, there are predatory attacks - maybe with the apex bear missing from most ecosystems, the black bears are becoming more aggressive
2. the problem with cougars is they will do a sneak attack, often above and from the rear - so be ready to fire over your shoulder before the teeth sink too far into the neck... (they are not likely to attack unless you are running)
- there is lots of info on attacks by wildlife; not sure how much is public and I dunno if Herrero's bear attacks database was every put on a public network, but you can read his book
https://www.amazon.com/Bear-Attacks-Their-Causes-Avoidance-dp-149302941X/dp/149302941X/ref=dp_ob_title_bk