That said, there’s a couple things:
1. You’re technically allowed to travel through anywhere with any firearms in the US (I only had a magazine, not a firearm) legally. That includes planes, but you have to check the bags. That said, they can still arrest you and not follow the law.
2. I carry a conceal carry permit with reciprocity with most states for this very reason. I actually showed it to them and it made things much smoother