Most of the time, all else being equal, the shorter the action the more accurate. We are not talking about big differences. Maybe not even enough for the average hunter to notice. The 308 however does have several things in its favor. 308 caliber bullets are good and there is a good variety to fit most poeples needs. It is a short but efficient casing that equals the 30-06 in bullets up to 165 grains. This with less powder and less recoil. It works well in short rifles and shoots as well in most cercumstances as rifles with longer barrels. The 308 will most often not loose velocity in a slightly shorter barrel. Brass is cheap and easy to find due to its many years as a military rifle. Its recoil makes it more shootable by more people yet will do just about anything the other 30 calibers will do. Given a little less range but as a rule its good to farther than most people can hit with a rifle anyway.