Have a read about what you have to do to cross American borders with ammunition and firearms.
The Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) regulates and restricts firearms and ammunition; and approves all import transactions involving weapons and ammunition. If you want to import or export weapons or ammunition, you must do so through a licensed importer, dealer, or manufacturer. Also, if the National Firearms Act prohibits certain weapons, ammunition, or similar devices from coming into the country, you will not be able to import them unless the ATF provides you with written authorization to do so.
You do not need an ATF permit if you can demonstrate that you are returning with the same firearms or ammunition that you took out of the United States. To prevent problems when returning, you should register your firearms and related equipment by taking them to any CBP office before you leave the United States. The CBP officer will register them on the same CBP Form-4457 used to register cameras or computers. (See the section on Register Items Before You Leave the United States).
For further information about importing weapons, contact the Bureau of Alcohol, Tobacco, Firearms and Explosives, U.S. Department of Justice, Washington, DC 20226; or call (202) 927-8320; or ( Bureau of Alcohol, Tobacco, Firearms and Explosives ) .
Many countries will not allow you to enter with a firearm even if you are only traveling through the country on the way to your final destination. If you plan to take your firearms or ammunition to another country, you should contact officials at that country’s embassy to learn about its regulations.
Kyle & Svet
comments always welcome.