You can play with ballistic charts all you want,but no 30/06 load can shoot as flat to 400 yards as a 270,although possibly the brand new 130 mono's from an 06 may do as well;but that's just one load with one bullet.
The '06 still can't catch up in trajectory if you compare apples to apples- compare the 130gr from the '06 to the 100-110gr from the .270.
