Have tried a number of long-gun and pistol cases, and really like the SKB cases. They are ATA (???) approved, and they now can be had with TSA locks. The old cases can not be retrofitted (have checked).
They have several layers and types of foam padding and do a great job of securing guns in the center of the case.
It is the only case I have been able to transport 2 silhouette rifles in at the same time without fear of them banging together.
Have several of them in different sizes, including one for a Sinclair front rest.
Check pricing on line at several places, as deals can be had.