Been there, done that, have the t-shirt, and hat, they want everything, pictures don't count. Also if they pay the claim, they keep the gun, though you may be able to negotiate, depending on the Postmaster. The middle ground would include only the cost of repair. Arm yourself, google the postal reg's under claims, and read up. Also The claim I believe has to be filed by the sender, which means you may have to send it back.
Bill