The 308 has slightly less MV than the 30-06 or 270 so with the same bullet you would have slightly more flight time resulting in more wind drift and of course more drop but with almost any bullet you should have plenty of energy left for deer size game. Of course if you go with a lighter bullet of say 150 or 130 grains it would give you higher MV which would help.
Either way, practice a lot and watch the wind.
