RE: Are bigger cartridges really better?
I've looked at quite a few griz/brown bear outfitters websites, and think overwhelmingly they suggested that the brown bear cartridges began at .300 win mag, and the .338 and .375 being much more ideal.
I was looking at my .340 cartridge recently and thinking, this is big? .300 mag casings pack a whollup sure, but to me it doesn't look like a big cartridge, in the sense of big dangerous animal, when that gun goes off I wanna know its being hit with some umphff. I think the .338 and .375 are quite ideal for brown bear.
My .340 also kicks less than my .300 win mag, so my view is that case size is all about the same kick/recoil. They're close/similar in recoil though. Also if you have a guide backing you up that does change things, but this is hunting and with dangerous game I wouldn't want to count on anyone else.
Also I think shooting a brown bear with a 300, certainly will kill a brown bear, I think the main argument with the bigger bores, comes when having to "stop" a charging animal, and when talking about that, bigger seems to be the conscensus as to stopping anything, bigger bore, bigger mass.