This final rule amends the regulations administered by the Alcohol and Tobacco Tax and Trade Bureau to reflect the small manufacturers excise tax exemption added by section 11131 of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users. Section 11131 amended section 4182 of the Internal Revenue Code of 1986 to exempt any pistol, revolver, or firearm from excise tax if it was manufactured, produced, or imported by a person who manufactures, produces, or imports less than an aggregate of 50 such articles during the calendar year.