The top revo is a S&@ 386 Mountain Lite which is a 357 and weighs in around 18oz empty. If really large bears are not an issue then load this one with a hardcast bullet - 7 rounds - and you are good to go.
The second revo is my personal favorite a S&W 629 Trail Boss - 3" barrel but somewhat heavy for serious backpacking. I have killed an angry black bear with a 44 magnum and, believe me, they are really tough.