So based on this accomplishment, I decided to upgrade him to a more modern, M4 type carbine with Eotech sight and other assorted toys. I took this rifle over to him last week and planned to bring his old HBAR back to Houston for some upgrades.
For the flight over, I took a sturdy, hard plastic rifle case I use for 3 gun. I took a plastic coated cable, ran to through the action and around the middle hinge on the case. I topped this off with a good heavy duty master lock and closed the case. No way this rifle was going to be separated from the case without a pair of bolt cutters. Next I closed the case and topped it off with the required TSA lock. (These are little "toy" locks that could easily be defeated with a pair of small diagonal cutting pliers.)
Flew over and back on Southwest. At the counters, the Southwest people were great. At both Hobby and Tampa they could not have been more gracious and did not bat an eyeball over the EBR. At Hobby, the SW folks took the guncase with my other luggage and away we went. No problem. In Tampa however, they advised I had to accompany a SW baggage guy over to TSA to check the rifle in with them.
Those TSA folks had a real attitude. They refused to take the gun case because it was "not secured properly". They told me I had to have TSA locks at every point in the case where a lock could be placed. (Three total on this case, one at the handle and on each end.) I politely advised the agent of my interior cable and lock set up and asked the agent to open the case and see for himself. He refused. I asked to talk to his supervisor and was told the same thing. She also refused to open the case to even look at my security set up. They finally advised they were more afraid someone could slip something "inside" the case with my rifle than they were my rifle would be stolen.

At this point I was pretty PO'ed but knew they were probably ready to slap the cuffs on this "Texas cracker with a gun" if I gave them the slightest reason. I kept quiet.
Fortunately, I was able to leave the gun there with TSA and wife overseeing, while I ran upstairs and found a shop selling the TSA approved toy locks. $25 and two more toy locks later, they accepted the case for the flight. We made our flight, but my rifle did not. It floated around as a "lost luggage" claim for an additional 24 hours. I had given up on ever seeing it again when it was finally delivered to my home in Houston yesterday.
Lessons learned.....(1) TSA interprets their regs far differently at different airports. (2) Next time I travel with a gun I will drive.