Thanks to NRA-ILA, there is a new DOT flier that replaces the previous erroneous information DOT was promulgating which was the apparent cause of TSA personnel confiscating +.50 ammunition. The new flier states that any ammunition not exceeding .75 is legal.

Print a copy and carry with you when traveling:
http://safetravel.dot.gov/index.html
click on Ammunition on the right top.

Unfortunately, they are still only half right, and ultimately wrong.

But I won't tell them if you won't.

Does/did the .50 caliber ban reference the actual bullet size or just what the rifle is stamped with? For example if you scratched off .505 Gibbs on your rifle and brass and labeled them both .499 would that get you around the ban (or at least a TSA agent)?

Thank you for posting the detail and link. Also great to see the new rules regarding the required ammunition's box and or container.
As a 505 Gibbs owner, this is great news.
Sincerely,

Thank you for the post LionHunter. I love to hunt with my 12.7x70mm Schuler. Leaving again for mother Africa and wasn't sure what to think. I was taking my Schuler anyway, but not sure ammo would make it. Not sure what I was going to do, shot .458 Win Mag thru it Maybe improve my accuarcy