Copied this from the FAA, using search http://www.faa.gov/ :
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Firearms and Ammunition may not be carried by a passenger on an aircraft. However, unloaded firearms may be transported in checked luggage if declared to the agent at check in and packed in a suitable container. Handguns must be in a locked container. Boxed small arms ammunition for personal use may be transported in checked luggage. Amounts may vary depending on the airline. [/quote]
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Firearms and Ammunition may not be carried by a passenger on an aircraft. However, unloaded firearms may be transported in checked luggage if declared to the agent at check in and packed in a suitable container. Handguns must be in a locked container. Boxed small arms ammunition for personal use may be transported in checked luggage. Amounts may vary depending on the airline. [/quote]