RE: 308 vs 30-06 vs 270
I am a big fan of the 308 Win. Have been for decades. My rifle and deveral of my friend's 308 Win/'s love 165-168 gr. spitzers at about 2600-2800 fps. A Winchester Model 88 in 308 Win. was my first "deer rifle". After it was stolen, I used a Browning BBR in 30.06 Spr. more or less exclusively from about 1974 until about 1990. Loaded with 165 gr. Partitions, it was about as good as it can get on wild pigs, white tails and mule deer, I suspect.
I know of no real big "cons" except maybe the 270 Win. being that the heavier bullets (150 gr. and up) sometime get a tad long for the rifle twist rates and are not as well stabilized as the 130 gr. bullets seem to be. A similar statement can be made about bullet weight and the 308 Win. , but for a different reason. Bullet weights in the 180-200 gr. can be loaded for the 308 Win. easily enough. It is just not optimum in my opinion, because the longer bullet takes up space that would otherwise be available for powder charge. Muzzle velocities really drop off when compared to the 30.06 Spr. using bullet weight above about 165 gr. Thi s is a case size issue.
In my opinion, for adequate performance across the widest range of bullet weights, it is the 30.06 Spr. Will handle anything from "Accelerators" to 220 gr. heavy hitting loads.
For white tail deer hunting... any of the 3 would be fine. For 300 yard shooting any of the 3. I know zip about hunting elk, moose. bear , etc. other than I never have !!!