Here`s alittle background. He`s 9 yrs old. Been shooting bb gun since he was 5. He`s bigger than most 9 yr olds(hieght and wieght). He`s saving money for a NEF single shot. I just don`t know if I should get him the 410 or 20 ga. He`s wanted to go deer hunting so that`ll be in his near future. What do I do?