If you're really worried about 3" or soof drop difference at 400yds then these two shouldn't have been mentioned as choices in the first place, as magnums would've been the only way to go(if you shoot farther you'd better be good enough at shooting sothe drop doesn't matter). Trajectory being knocked off the list as something to worry about, the 30-06 can be shot very cheaply, it being an ex-mil. cartridge, and has a lot more bullet choices at 30 caliber than 27 caliber. Recoil? If you're worried about it go shoot a 243, or put on an inexpensive limbsaver to make it feel like one. The 30-06 has a better rep. for accuracy than the 270; I've never heard of a competition rifle in 270. So you've got my opinion, 30-06.