Firearms and Ammunition, generally speaking, purchased in the United States and taken out of the country by a resident may also be imported back into the country. However, it is the responsibility of the returning resident to provide a bill of sale or commercial documents indicating proof of possession or ownership. A customs form 4455 or 457, "Certificate of Registration" may be used for this purpose.
Guns and ammunition purchased outside the United States, however, are subject to complicated clearing procedures and are very difficult to import. You will need to apply for a permit through the Application and Permit for Importation of Firearms, Ammunition and Implements of War", ATF form 6, from Bureau of Alcohol, Tobacco and Firearms, Department of the Treasury, Washington, D.C. 20226, phone (202) 927-8320, Fax (202) 927-8601. It is recommended that anyone considering the shipment of foreign-purchased guns into the States consult with the local U.S. consulate prior to departure. Due to risk of accidental explosion, North American policy stipulates that ammunition may not be shipped with your household goods.
Firearms manufactured before 1898 may be imported into the United States without difficulty. But make certain that the gun is a genuine antique; replica firearms require authorization by the Bureau of Alcohol, Tobacco and Firearms (BATF) in order to clear customs.
International Moving and Knives
Weapons with fixed blades are generally permitted in the United States. However, souvenirs such as swords, camel whips, machetes, and similar articles capable of being used as weapons may still be in violation of local and state laws According to U.S. Customs: "Knives designed for utilitarian use, such as household purposes, personal grooming, trade or professional employment, crafts or hobbies, hunting and fishing, and scouting activities, are also permitted unrestricted entry, provided that the imported knife does not open automatically and is not a switchblade".