Has anybody taken a suppressor from the US to RSA or Namibia and back? Just had a Blaser .300 Weatherby barrel threaded and have a Thunderbeast Ultra 7 awaiting approval. I'm thinking of taking it next time. I think some are doing it. I am wondering about the process.

I doubt many people do it. To get dependable information, a travel agent familiar with firearms and travel would probably be a good source.

What I suspect is that some sort of approval would probably be needed from the State Department. Then what would ensue if you happened to have an unexpected lay over in a place where supressors were illegal? Each to his own, but I wouldn't complicate my life that way.

A "class 3" neighbor told me it's impossible to take them out of the country. It's the ATF that will be the problem, not other counrty's regs. Suppressors are treated like screw drivers in most of the civilized world.
Case in point: In '14 I shared a camp in Namibia with 2 guys from U.K. who each had moderators (that's what they call 'em) on their .308s. They said there was zero paper work in owning them in Britain or in traveling with them internationally.

I am wanting to use them for hearing protection reasons. I asked the safari operator on my last trip and he said he had Americans bring them. I asked the customs officials clearing guns in Atlanta and they said they had seen a few come through. I asked whether it is legal to take them out of the US and back and they said that is a question you should ask of the ATF.