A 270 is certainly adequate for hunting moose. Heavier premium bullets are needed in this or any other caliber you mention here. The 30-06 loaded with 180, or better yet, 200 grain Nosler partition bullets is your best bet here. The 308 with 165 grain premium bullets will also work fine, but remember it is the least of the 3 you mention here. Given your list of choices, you will be best served by the 30-06 if the recoil isn't too much for you. If the 30s make you flinch (then you miss) go with the 270, because placement of the shot is of much greater importance than the caliber you shoot with. J
