I don't know if you want low cost also, but you can shoot very light loads with a Savage and get excellent performance out to 100 with lighter bullets. I have heard of like 35g of 5744 behind a 200g XTP or 200g Shockwave or a 195g Barnes is a very manageable load for a youth. Also a hawken or renegade in percussion would be excellent. An Omega is great also, since there is no safety to mess wth and pulling the hammer backs cocks the gun. Best Wishes for your new Huntin buddy, it is the great thrill of life in my opinion, giving your son a love of God and a love of the outdoors.
Chap