That may be so:III% Steve is right. They are not allowed to cut locks off of checked baggage with a DECLARED firearm inside. They have to contact you (the owner, and only person that (should) have the key/combo) to come open it, if any additional inspection is requested by TSA.
"Yes, TSA might clear your gun case upon your departure. Yes, some other TSA agent may cut your locks off somewhere between your departure gate and your final destination. They’re not supposed to without a really good reason, but it happens. Again, that’s your tax dollars at work. You can yell, scream and stomp your feet, but you won’t win that battle. Accept the cost of new locks as part of doing business. On the other hand, if your guns are missing, I personally would tell the airline and destination TSA agents that I was calling the FBI immediately to report an interstate theft of firearms. That ought to get you some attention.
I’ve flown many, many times with one or more firearms and have never had a serious issue. Yes, some airports act differently, but I’ve never lost a gun or had a serious run in with the G-men."
Mr. McHale also had some points about different destinations having their own rules, eg. traveling to Bend, OR, and New York. Good information if your packing a Phantom who carries.

10 Gun Tips You Need To Know About Flying With Guns