Whether you occasionally or regularly transport ammunition aboard a passenger aircraft, you should know how to pack ammunition safely and securely. Properly packaged, small arms ammunition for personal use may be safely transported aboard commercial aircraft
in checked baggage only. Additional rules from the airline may apply, so check with your air carrier before you leave for your trip.
The Transportation Security Administration has a document called the TSA Public Education Fact Sheet, Transporting Firearms and Ammunition Aboard Commercial Air Carriers that outlines the rules for securely transporting firearms and ammunition
Other information from TSA on transporting firearms and ammunition can be found from TSA
http://www.tsa.gov/travelers/airtravel/assistant/editorial_1666.shtm The Bureau of Alcohol Tobacco Firearms and Explosives is a valuable source of additional information on firearms safety
www.atf.gov/firearms