If your son ships the pistol to Colt, it will need to go UPS or FedEx Next day- about $70. However, you can find a DEALER in your area that can MAIL it by US Mail- it is legal for a DEALER or MANUFACTURER to mail handguns- but not us unwashed masses types. Even after paying a dealer for his time, and a $10 one price Priority Mail box, it will be cheaper. My advice- send it back. PS- go to gunbroker.com, use the "find a ffl" feature, based on his zip code, listing of dealers that have registered as doing firearm transfers. colt can return the sidearm directly to him when finished.