A good quality 3-9x40 is all the scope necessary for any big game hunting situations out to any range anyone has any business shooting at big game.

If you cannot do it with a 3-9, then more experience is needed.

At most, a 3-10X40 or 3-10x50 with stadia wires will be good. I suggest Leupold, Burris or Swarovski.

Long range shooting at big game brings forth hunting ethics questions in many people.