Post 9/11, you may be interested to see the regulations governing handguns and related paraphernalia on US aeroplanes:

"Firearms and starter pistols may be transported in checked baggage so long as they are unloaded and declared to the airline at the ticket counter before you go to the screening checkpoint.

Small arms ammunition for personal use may be carried in checked baggage but only if securely packed in fiber, wood or metal boxes, or other packaging specifically designed to carry small amounts of ammunition.

One self-defense spray (pepper spray or mace) not exceeding 4 fl. oz. may be carried in a checked bag if it has a positive means to prevent accidental discharge."