Not going to make a recommendation per se about appropriate caliber/cartridge for the big bears but wanted to pipe in about using brakes in hunting situations, I have only carried a gun in brown bear country for protection never hunted them. Although, I will admit to using a Ruger 375 as my primary black bear gun, two big holes is better than 1 or 2 smaller ones.
Yes, with proper ear protection brakes can make big boomers more comfortable to shoot but if the ear pro is not worn one shot of a braked rifle can cause permanent damage to your hearing and those around you. Once you lose you sustain hearing damage there is no fix other than hearing aids.
Some people worry about damage to a shoulder from heavy recoil but some of that can be mitigated like using a brake when sighting in and developing loads. Make sure you check for any zero change with and without a brake.
Shooting without a brake the worse case scenario (shoulder-wise) is you injure your shoulder, surgeons can do amazing things to fix up an injured shoulder. I have had 3 shouder reconstructions on my right side so I speak from experience, none of the damage was due to recoil. I can fire 20 rounds from my 375 Ruger with only a little soreness the next day.
Long story short, I would rather risk shoulder injury than hearing loss,
wade