For bears I would look to the ammo from Buffaloe Bore, and Corbon,, thats for bears as in BIG BLACKS, don't know enough about the Grizz or Coasties to say.
One of my guide friends who would over winter at the lodge by himself carried a 444. He would shoot around five moose and assorted nuisance bears both black and brown each year, on a Homestead license. He would use factory 165 grain loads on moose but if specifically for bear he would use the Corbon load. These were a huge step up in performance and recoil. They made the 444 almost equal to a heavily loaded 45/70. As a fishing/self defense rifle not a bad choice with the Corbon or Buffalo Bore loads. For Hunting give me something that is better to two hundred yards even though the 444 is capable of this.
In a lever action I would go for Teddy Roosevelt's "Big Lion Medicine" the 405 with modern hand loads.
