That’s one area where I’m pretty persnickety: I will not use a bag as a carryon if it has EVER been to the range with me. I know all of the guns would be out of it, but I’ve had bags poop live rounds months after I’ve taken them to the range. As I understand it, TSA isn’t as down on ammo as they are with firearms, but it’s still good for an arrest and a fine, IIRC. CC
I’ve actually serialized all of mine, but only because I want to have a S/N to report to LE if any of them are ever stolen.