When you travel by air with your firearm do not leave the magazine in your semi-auto. Especially if the magazine is loaded. Claiming that having an empty chamber counts as an unloaded gun may not work. Some jurisdictions may even consider the gun loaded if the magazine is loaded and in a different suitcase from the gun.
I once had two TSA employees argue for 15 minuts about a loaded magazine I had even with the gun completely empty. The smarter of the two finally won that arguement but I could have had to argue that point myself to a prosecutor and/or judge. And one time I wait for over 30 minutes because the TSA guy claimed he couldn’t determine via the X-ray if the magazine in the grip of my Ruger P-89 was empty or loaded. The rules wouldn’t allow him to touch the gun and drop the magazine to check it out, I wasn’t allowed to touch anything once they had it under their control. So we to wait for a police officer to arrive from some distant city or something to take all of five seconds to pick up the gun drop the magazine, say, “It’s fine.”, reinsert the magazine, put my gun back in it’s case and walk off.