UPS policy:
www.ups.com/using/services/details/firearms.html
From the UPS tariff (actually, 22 as opposed to 120 pages)Firearms will be transported only between licensed importers, licensed manufacturers, licensed dealers and licensed collectors, as defined in the United States Gun Control Act of 1968 (Public Law 90-618, enacted
October 22, 1968), as amended by the Firearms Owners' Protection Act (P.L. 99-308, approved May 19, 1986, and a subsequent amendment thereto, P.L. 99-360, approved July 8, 1986) (“the Acts”), law enforcement agencies of the United States or of any department or agency thereof, and law enforcement agencies of any State or any department, agency or political subdivision thereof, and from a person not
otherwise prohibited by Federal, State or local law[i/] to a licensed importer, licensed manufacturer or licensed dealer for the sole purpose of repair or customizing, and the repaired firearm or a replacement firearm of the
same kind or type on return from the licensed importer, licensed manufacturer or licensed dealer to that person. The shipper must affix a UPS label, requesting an adult signature upon delivery, to each package containing a firearm. Adult means a person 21 years of age or older. Handguns, as defined by the Acts, will only be accepted for transportation in UPS Next Day Air Services, but will not be accepted for transportation via UPS Letter Centers, Internet Shipping, or in response to a request for a One-Time Pickup or for On-Call Pickup Service. Firearms, including handguns, will not be accepted when presented for shipment at a UPS
Authorized Shipping Outlet or a UPS Commercial Counter. Small arms ammunition, as defined in 49 C.F.R. Section 173.59, will be transported only when packaged and labeled in compliance with 49 C.F.R. Section 172. (italics mine).