Ak, I have lived and hunted in the Alaska Peninsula and Bristol Bay area since 1978 and I've only packed the 30-06 and since 1981, a 300 win mag and I don't feel too worried about bullet diameter. I don't mess with bear hunting much. This fall trying some still hunting for moose in real thick stuff, I felt a little edgy at one point but just put in some 220 Nosler loads and kept going. I'm not at all sure we really need the elephant guns as much as the press likes to whip up the issue.
I agree with Lone Star that the std .338 would make a dandy choice and I have thought hard about rebarreling for that myself.
After several days of packing this 8.5 to 9 lb gun across miles of tundra and through alders, I've thought hard about going to a 338-06, 35 Whelen,or 9.3x62 too, in a lighter gun but more rounds in the magazine.
When I had this 300 built, my first choice was the 308 Norma but I opted for the more available 300 win for convenience. I wouldn't short change the 30-338 unless you find the wild cat is too much hassle.