Section 555.108 - Importation(a) Explosive materials imported or brought into the United States by a licensed importer or holder of a user permit may be released from customs custody to the licensed importer or holder of a user permit upon proof of his status as a licensed importer or holder of a user permit. Proof of status must be made by the licensed importer or holder of a user permit furnishing to the customs officer a certified copy of his license or permit (see §555.103 ).(b) A nonlicensee or nonpermittee may import or bring into the United States commercially manufactured black powder in quantities not to exceed 50 pounds. Upon submitting to the customs officer completed ATF F 5400.3, certifying that the black powder is intended to be used solely for sporting, recreational, or cultural purposes in antique firearms or in antique devices, black powder may be released from customs custody. The disposition of the executed ATF F 5400.3 will be in accordance with the instructions on the form.(c) The provisions of this section are in addition to, and are not in lieu of, any applicable requirement under 27 CFR Part 447.(d) For additional requirements relating to the importation of plastic explosives into the United States on or after April 24, 1997, see §555.183.(e) For requirements relating to the marking of imported explosive materials, see §555.109.T.D. ATF-87, 46 FR 40384, 8/7/1981, as amended by T.D. ATF-387, 62 FR 8376, 2/25/1997; ATF No. 1, 68 FR 13790, 3/20/2003; ATF 5F, 70 FR 30633, 5/27/2005