Originally Posted by jkhuggins

At that point, I think a simple call to the airline would be in order ...

"Hi, you're now in possession of a firearm for which you don't have a license. In your airport, that might mean that you're currently guilty of a felony. Furthermore, now that you've broken the lock, you're now wholly responsible if that firearm is stolen from my unsecured suitcase and used to commit a crime. When would you like me to call the ATF?"

At that point, I think the airline would find a way to get that hot potato back to you as fast as humanly possible.

Disclaimer: I have no knowledge of how this would really work; I don't own a firearm. My conjecture above is based solely on reading other's experiences here on FlyerTalk.