Hi Doug and welcome. It would be better to purchase a gift card in the full amount of the purchase so your son can buy it in his name so there are no appearances of a straw purchase. budsgunshop.com/search.php/type/buds+gift+cards

Hi Doug, the ATF recommends that if you want to give someone a new firearm, rather than going to a gun store, buying it on your own and giving it to, say, your father, consider instead purchasing a gift certificate from that retailer and giving it to dad as his present. That way he will get the exact gun he wants, and there’s no question about who is “the actual buyer of the firearm,” which is a question any purchaser must certify on the Form 4473 at the time of purchase.
Stay safe & have a great day!