Suggest any quality variable scope suitable for use on a center fire rifle. Something like a 1.5-6x 32 or 40 mm should be ideal. You should expect the Savage 220 to shot very good groups and be very effective out 150 yards +/-. A scope in the class of a Leupold Vari-X III, Bushnell Elite 4200 or Ziess Conquest should perform very well and give you many years of great service. I suggest that you do a good deal of range testing because the "slug loads" have a relatively slow muzzle velocity and poor ballistic coefficients. The arc is rather dramatic, especially past 100-125 yards.