26 U.S.C. § 5852: General transfer and making tax exemption

Any firearm may be transferred to the United States or any department, independent establishment, or agency thereof, without payment of the transfer tax imposed by section 5811. Any firearm may be made by, or on behalf of, the United States, or any department, independent establishment, or agency thereof, without payment of the making tax imposed by section 5821. A manufacturer qualified under this chapter to engage in such business may make the type of firearm which he is qualified to manufacture without payment of the making tax imposed by section 5821. A firearm registered to a person qualified under this chapter to engage in business as an importer, manufacturer, or dealer may be transferred by that person without payment of the transfer tax imposed by section 5811 to any other person qualified under this chapter to manufacture, import, or deal in that type of firearm. An unserviceable firearm may be transferred as a curio or ornament without payment of the transfer tax imposed by section 5811, under such requirements as the Secretary may by regulations prescribe. No firearm may be transferred or made exempt from tax under the provisions of this section unless the transfer or making is performed pursuant to an application in such form and manner as the Secretary may by regulations prescribe.