HTS code 9303.10.00.00 covers "Other firearms and similar devices which operate by the firing of an explosive charge (for example, sporting shot- guns and rifles, muzzle-loading firearms, Very pistols and other devices designed to project only signal flares, pistols and revolvers for firing blank ammunition, captive-bolt humane killers, line-throwing guns) › Muzzle-loading firearms" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.