Why are some folks infatuated with the smallest tool available to do a job? Why even concern ourselves with "minimums"? I mean who cares?
We have among us,collectively, over 100 years experience with center fire cartridges and bullets to draw on today;more choices than ever before (many overlapping in performance so that it would take a swami to distinguish them)and so many far better bullets, that making a choice to kill a brown bear or anything else should be easy.
I remember when Skane was going on his first brown bear hunt...we talked and I am sure he talked to others as well. He had a 35 Whelen...I thought that was fine and told him as much,because people had been killing brown bear with 35 Whelens for decades(along with smaller and larger cartridges). A reasonable middle ground seemed like a good place to be.
He asked about bullets and we talked about 225 Northforks,so that's what he used.As I recall his bear went absolutely no where,because he used a reasonable cartridge,a very good bullet,and because he knows how to shoot.
Concerning ourselves with minimums is just a waste of grey matter with so many good choices available today....JMHO.