Most large-caliber ammunition and ordnance items are controlled under the US Munitions List (USML) and therefore subject to ITAR. Importation requires a DDTC import authorization, and the foreign exporter typically also needs an export license from their home country. Even inert or demilitarized ordnance components may remain USML-controlled; importers should seek a DDTC commodity jurisdiction determination when the status of a specific article is unclear.

CBP handles the customs entry and physical examination at the port of entry, while DDTC controls whether the importation is legally authorized under ITAR. Both agencies must be satisfied before goods are released. In practice, the DDTC import authorization must be in place before the shipment departs the country of origin, making advance regulatory coordination essential.