Under the Gun Control Act, the frame or receiver is the regulated firearm component requiring an ATF import permit and serial number. Slides, barrels, and other parts are regulated as firearm parts but are not themselves firearms. However, importers of any pistol component should confirm current ATF guidance, as regulatory interpretations—particularly for partially completed frames—have evolved in recent years.

Pistol parts originating from countries subject to Section 301 tariff actions may carry additional duties on top of the standard MFN rate. Importers should verify the applicable HTS subheading and origin of each component, as the Section 301 lists are product- and country-specific. Working with a licensed customs broker to confirm current duty exposure before placing orders can prevent unexpected landed-cost increases.