Interesting thread... I've thought about this stuf myself.

I went on my first hunt out west this year and killed a buck with the same .308 I hunt whitetails with here in PA. I had no intention of buying a different rifle just for the sake of that hunt. I still would have used the same gun if I had drawn an elk tag. I sighted in a little higher at 100 yards than I normally would have and practiced out to 300 yards regularly. I had extreme confidence that if I could get within 250 yards of a buck he was dead. The buck I took was at 225 yards give or take. He didn't care that I wasn't using a magnum.

Sometimes I think there is too much made of all this when a round like the old30-06 or a .308 can get the job done pretty well regardless of location.