A .44 magnum is not adequate for bear?? Something we all need to remember is that a .44 magnum is a VERY POWERFUL round and has been around a long time, it has taken some of the largest game on earth, and will continue to do so.
The .44 magnum is the round all others are compared to, from less powerful rounds right up to today's monster handgun rounds. Are you better off with a .454 Casull, .460 or .500 Smith or one of the Linebaugh offerings, maybe so but don't shy away from the .44 magnum for big game, it's plenty adequate in the right hands.