I would set a three pin sight at 20, 30 and 40. You may never need a 40 yard pin, but using the gap between the pins you will have accurate setting form 25 and 35 yards and I'm sure this will be in your capability, if not now, in the near future. You're 20 yard pin will shoot 1" high at 15 yards. That's no big deal, unless your shooting squirrels.