Have said this many times before, that in my experience both guiding hunters and hunting for myself here in the Yukon, it is my distinct impression that I have seen more one-shot kills with the 270 Winchester than anything else.
From grizzlies to gophers, it just plain works. So does the 30-06, all of the magnums, and the medium bores at 2000 fps and faster. We can help ourselves to whatever flavour we care to use on any one day. I know a few guys who still carry Model 94s and fill their freezer almost every fall.
I believe the reason the 270 did so well, and still does, is because it is not only very accurate and adequate for all big game, but is easier to shoot well than heavier recoiling rifles. Sighted in three inches high at 100, it also shoots flat enough for dead-on holds to 300 yards, and consequently most do well with it in the field.
Our weather is shaping up for a very early Spring, and a few bears are out already. I have killed lots of bears with the 270, but it will stay in the safe and the 9.3X62 will be in the canoe.
Whatever you choose to use, best of luck to all of you this year.
Ted