My friends son took a bear with his 375 h&h a year or two ago in Alaska. Not sure on the load but the shot was about 200 yds broadside with a double lung. The bear began heading their direction so he put another into its chest head on. The 3rd shot he caught the shoulder which put him down 90yds out but the bear was still rolling around. It was just under 800 lbs so its a decent bear but man thats a tough animal. Think big and heavy definately with your bullet choice no matter what caliber you choose but Id put the 375 at the min IMO. Just my 2 cents after hearing about their hunt.