Can't go wrong with 270 win, 7mm mag, 30-06 or a 300 win mag. If I was to choose a standard cartridge it would be the 270 win. If I was to choose the magnum I would choose the 300 win mag. But all four are well capable with the right loads to go from 0-500 yards without an issue of trajectory or ft lbs of energy. There's not much of a debate on which is best. If your going to shoot a lot of stuff around the 500 yard mark would be hard to deny the magnums holding the better ballistics. But beware of buying a magnum in cheap light weight guns they will punish you in recoil.