US Code, Chapter 44, Section 18, subsection 922 (e)
https://www.atf.gov/firearms/qa/may-non ... ct-carrierThanks for the links. I am not sure the ATF site is giving good information. If you look at the referenced law, and if I am reading it correctly (disclaimer: I am not an attorney), the requirement for notification of the carrier appears to have an exception for delivery to licensed importers, manufacturers, dealers, or collectors. These are the cases I was referring to. Let me know if you read it that way.
e) It shall be unlawful for any person knowingly to deliver or cause to be delivered to any common or contract carrier for transportation or shipment in interstate or foreign commerce, to persons
other than licensed importers, licensed manufacturers, licensed dealers, or licensed collectors, any package or other container in which there is any firearm or ammunition
without written notice to the carrier that such firearm or ammunition is being transported or shipped; except that any passenger who owns or legally possesses a firearm or ammunition being transported aboard any common or contract carrier for movement with the passenger in interstate or foreign commerce may deliver said firearm or ammunition into the custody of the pilot, captain, conductor or operator of such common or contract carrier for the duration of the trip without violating any of the provisions of this chapter. No common or contract carrier shall require or cause any label, tag, or other written notice to be placed on the outside of any package, luggage, or other container that such package, luggage, or other container contains a firearm.
(f)(1) It shall be unlawful for any common or contract carrier to transport or deliver in interstate or foreign commerce any firearm or ammunition with knowledge or reasonable cause to
believe that the shipment, transportation, or receipt thereof would be in violation of the provisions of this chapter.
§ 478.31 Delivery by common or contract carrier.
(a) No person shall knowingly deliver or cause to be delivered to any common or contract carrier for transportation or shipment in interstate or foreign commerce to any person
other than a licensed importer, licensed manufacturer, licensed dealer, or licensed collector, any package or other container in which there is any firearm or ammunition without written notice to the carrier that such firearm or ammunition is being transported or shipped: Provided, That any passenger who owns or legally possesses a firearm or ammunition being transported aboard any common or contract carrier for movement with the passenger in interstate or foreign commerce may deliver said firearm or ammunition into the custody of the pilot, captain, conductor or operator of such common or contract carrier for the duration of that trip without violating any provision of this part.
(b) No common or contract carrier shall require or cause any label, tag, or other written notice to be placed on the outside of any package, luggage, or other container indicating that such package, luggage, or other container contains a firearm.
(c) No common or contract carrier shall transport or deliver in interstate or foreign commerce any firearm or ammunition with knowledge or reasonable cause to believe that the shipment, transportation, or receipt thereof would be in violation of any provision of this part: Provided, however, That the provisions of this paragraph shall not apply in respect to the transportation of firearms or ammunition in in-bond shipment under Customs laws and regulations.
(d) No common or contract carrier shall knowingly deliver in interstate or foreign commerce any firearm without obtaining written acknowledgement of receipt from the recipient of the package or other container in which there is a firearm: Provided, That this paragraph shall not apply with respect to the return of a firearm to a passenger who places firearms in the carrier's custody for the duration of the trip.
[ 33 FR 18555, Dec. 14, 1968. Redesignated at 40 FR 16385, Apr. 15, 1975, and amended by T.D. ATF-354, 59 FR 7112, Feb. 14, 1994; T.D. ATF-361, 60 FR 10786, Feb. 27, 1995]