Another one for 7mm-08 , idk if you can load sub sonic rounds that will still have enough punch to kill a deer though, last thing the kid needs is to wound a bunch of deer, also it IS legal to get a silencer, it takes about a year or so after you file the paper work!! When it comes to him actually hunting with it I don't know if it's legal but it would help while practicing, when it comes time for him to actually shoot a deer or whatever, I bet his adrenaline takes over and he won't even hear the gun or feel the recoil

good luck to the young man.. Go gettum kid !!!