I love the big guns, but my father-in-law and I argue about it sometimes.
He killed a 5X5 bull a few years with a very well placed 140 grain bullet out of his30 year old .264 Win mag at about 400 yards, he says I can take my cannon and stick it up my... Well you know what I mean.
I guess I can't argue with him too much, he's taken more elk with that than my I have with my 300's