The following tutorial will show you around the part 479 landing page.
27 CFR Part 447
Importation of Arms, Ammunition and Implements of War
27 CFR Part 478
Commerce in Firearms and Ammunition
27 CFR Part 479
Machine Guns, Destructive Devices, and Certain Other Firearms
27 CFR Part 555
Commerce in Explosives
27 CFR Part 646
Contraband Cigarettes
27 CFR Part 771
Rules of Practice in Explosive License and Permit Proceedings
Effective date is the date this part was last amended
Except as otherwise provided in this part, each transfer of a firearm in the United States is subject to a tax to be represented by an adhesive stamp of the proper denomination bearing the words “National Firearms Act” to be affixed to the Form 4 (Firearms), Application for Transfer and Registration of Firearm, as provided in this subpart.