338 win mag hands down. used to be the day i would say 30-06. but with grizz or brown bear, the 30-06 is marginal for close up saftey. the 30-06 is not a fight stopper. its good when someone is backing you up.. the 338 is not too much for deer or sheep, what the doctor ordered for elk and moose, and made for big bear.. the handload 300 grain 338 win mag bullet will out penetrate in any test media the 300 grain 375hh bullet.. the 6 and a halfs, 7's and 33's penetrate like drill steels.