foxfire,
You don't say how old your son is, but I'm assuming he's not of an age where he could buy his own without dad doing the paperwork. This might be a good time to teach him a couple of real world lessons, by letting him work for and purchase his own.

1) Tell him if he can save up the money (from chores, mowing lawns, cleaning out barns, hauling hay, shoveling snow, whatever he can do) for the full purchase price, you'll do the paper work for him and the gun will be his.

2) It sounds like you have some pretty nice firearms and I'm sure the guns you have given him are of good quality. If he is able to get the funds for a new gun, off the shelf, he will see that New does not always mean Better.

He gets lessons in economics, quality, value of well cared for items, plus, he gets the pride of ownership of something he purchased from money he earned by the sweat of his brow.