More important than the caliber is the bullet construction.
IMHO, and I lived iin SE Alaska and hunted brownies, if you are used to your rifle and shoot it regularly, get a good bullet i.e. nosler partition, swift a-frame. Make sure you can hit what you are shooting at, then have a good time.
When I lived up there, a deer hunter was killed by a brownie, around a dozen people went after it, armed with .338's, .300's, 7mm's, and a .30-30
The high velocity factory rounds for the mag's were loaded with deer bullets. And had explosive expansion, little penetration, the .30-30 was the round that penetrated and killed the bear.
You will do fine, enjoy.
btw, one bit of advice, first shot, take out his front shoulders, hopefully the heart and lungs at the same time. That way you are sure to slow him down if you don't kill him with the first shot.