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
(v) Size and depth of markings. The engraving, casting, or stamping (impressing) of the serial number and additional information must be to a minimum depth of .003 inch, and the serial number and any associated license number in a print size no smaller than 1/16 inch. The size of the serial and license number is measured as the distance between the latitudinal ends of the character impression bottoms (bases..
(5) Size and depth of markings. The engraving, casting, or stamping (impressing) of the serial number and additional information must be to a minimum depth of .003 inch, and the serial number and any associated license number in a print size no smaller than 1/16 inch. The size of the serial and license number is measured as the distance between the latitudinal ends of the character impression bottoms (bases..
(5) If licensed manufacturers or licensed importers desire to use a coding system and omit printed markings on the container that show all the required information specified in paragraphs (b)(1) and (2) of this section, they must file with ATF a letterhead application displaying the coding that they plan to use and explaining the manner of its application. The Director must approve the application before the proposed coding can be used.
(i) Privately made firearms. Except for adjustment or repair of a firearm that is returned to the person from whom it was received on the same day, licensees must record each receipt or other acquisition (including from a personal collection) and disposition (including to a personal collection) of a privately made firearm as required by this part. For purposes of this paragraph, the terms "receipt" and "acquisition" shall include same-day or on-the-sp..
(ii) Ruger Mark IV pistol: The frame is the upper part of the weapon that provides housing for the bolt or breechblock.