A brown bear does not drop easy. My hunting buddy has shot 4 brownies and from those experiences he has the highest respect for the capabiliteis of a wounded grizzly. The last one he shot with a 375 mag. Bullet passed thru the shoulder completely shattering the whole upper leg and going on thru the lung. the second shot went thru the heart turning it into jelly. In spite of this the bear ran. But it did come back for a charge when he and his son tracked it. The bear was finally dropped for good on that final charge by 2 more shots from the 375 and one from his sons 30.06. It wasnt a matter of grain size, or velocity or even ft.lbs. of energy. It is more an animal that dont go down easy and is capable of doing major damage in a short time. If a bear like this can run on shattered bones and no heart how can anyone expect a round of buckshot to do any real damage. this is by far the most dangerous critter most of us will ever even think about having to confront. We will be going out this weekend for brownies and you wont see a shotgun between us. A 375, a 45/70, and a 338 win mag. Why? Cuz these are some of the rounds that have proven the most effective in these parts. A couple weeks ago a man and women were caribou hunting in the Denali Highway area. After filling their tags they spotted a gizzly in a field of berries and the guy put two shots from a 458 winchester in it.The bear ran into some alders so they decided to wait till the A.M. to go look for it. That bear despite being hit in the boiler room with at least one good shot was still able to charge and maul the guy before his wife was able to dispatch it with her 338. Forgive the rambling but when it comes to brownies and grizzlys there isnt much room to re-invent the wheel so to speak.You might want to at least talk to folks that encounter these bears on a somewhat regular basis before you go out and risk yours or some other unsuspecting persons life.