I have 3 30-06's and three 308's. With the 30-06 there is no rational reason other than I just happen to like all 3.
I actually have a plan with the 308's. One is a lightweight Kimber for those times I need a lightweight rifle. One is a standard weight for general use. The 3rd is a cheap beater that I don't worry too much about it if it were to get stolen from my truck or fall off the ATV.
Some guys worry themselves sick over the differences between a 270 and 280. Personally I don't think there is all that much difference between most anything from 7-08 up to 375 magnum. I'd just as soon have multiple rifles set up differently in the same caliber than multiple rifles in different calibers. Saves time and expense on loading or buying ammo.
