I have a ten yr old that I think is now mature enough too start shooting more then his bb gun He goes with me hunting alot and it is only two years away until he is of age too get his hunting liscense. What should I start him on? He has shot a bb gun alot so now should I upgrade too a .17 or .22? And at what point do u determine what caliber he should use for deer hunting in a couple yrs. when he hits 12.