Because you said whitetail deer I would choose the .270

However, if you ever thought about wanting to go for larger animals, like moose or black bear I think .308 might be a better choice.
IMO - They shoot heavier bullets better from the ammo manufactures. ~ I don't reload, so I can't comment on that side of things....
To me and my rifle, I shoot .130 grain bullets and every time I try a heavier bullet I loose accuracy.
So I have half concluded on my own, that a .270 is a 130 grain bullet gun??!!!...

After mentioning this, I would consider bumping up to a .30-06, for the larger game example, plus it's flatter shooting for longer distances

Lastly, any well placed, broad side shot will put any of these animals down without a problem.
Moral of the story... Shoot accurately and smart/ethically!