It would help to know what you son wants to shoot. Does he want the weapon for hunting or is he going to use it for competition. How old is he and what is his body build? Has he mastered good shooting technique with the .22 or is he just wanting something with more punch?
Shot group is the order of the day. Never hunted a day in my life, but for the two-legged kind.
(Actually, anybody know how to skin a cow?)