pattern your 410 at twenty yards and see how many pellets are in the kill zone. don't move to a 20 gauge if your son isn't comfortable shooting. one he will prob flinch and miss the bird and also if your son enjoys shooting the 410 he is at a stage where he needs to enjoy hunting and not be afraid. it needs to be fun for him and if a 410 is fun then that is what he needs. hope he gets him one. good luck