Certainly someone could suggest another cartridge than the 270 or 7mm-08, and possibly argue its merits on some of the finer points of target shooting. But your choices are certainly top-of-the-line in terms of doing the job you indicate (target shooting 300+ yards, deer and elk hunting). You will have good bullet selection, even in factory loads, for the 270 and the 7mm. I think there is much more to be gained in choosing the model/style of rifle and quality optics than in choosing another caliber.
Just my opinion, of course!