If you want a larger caliber in case of larger game, both the .30-06 and 7mm-08 are better options than the .308.
The 30-06 offers slightly more than the 308win for larger game,but the 7mm-08 actually offers a little less for larger game.After all,the 7mm-08 is basically just a necked down 308win.With the same case,the slightly larger bullet makes the 308win slightly more suited to larger game like elk or moose than the 7mm-08.