Assuming the goal is turkey hunting, here is what I would do. Get some turkey loads (3" shells, 1 1/4 oz of #6 lead or #7 hevi-shot). YOU pattern the gun and make sure it shoots to point of aim and if not get some adjustable sights so it does. Have the young man practice only with the lightest and slowest loads you can find for him, including some dry firing on a snap cap or spent shell. The first time he shoots a turkey load from that light gun should be at a turkey. If he practices with hard-kicking loads he will get a flinch. He won't notice the recoil if he's got a turkey in front of him.
