mjw176, you are asking a question that has been argued heatedly since before I was born. To answer your .270 vs. .30-06 question would entail a lot of typing to say a very simple thing, it all depends on the bullets fired. There are a lot of differences in bullets of the same weight between .308 and the .277 bullets. And with some of them, the .277 will have a better over all ballistic coefficient and with others the .308 will come out on top. Then you have the rifle itself to consider, as in, consistent chamber dimensions, bore cut, rifling, barrel thickness, bolt face true or not, even cartridge variations can come into play. I myself feel, overall, the .30-06 has the advantage over the .270 and the .300wm squeeks a little ahead of the .30-06 because of the longer range with a heavier bullet but as Flags and others mentioned, in ranges that 99% of hunters should ethically even think of taking a shot, there is really no difference between the .300wm and the .30-06. Past around 400 yards, the .300wm will have a good advantage. That initial +300fps combined with a good BC bullet will carry a lot more energy downrange than most think.