Comment by walrus01
16 hours ago
These things are also notoriously prone to false negatives. I know a person who uses the same laptop briefcase to take their handgun to the local indoor shooting range, with magazines and ammo, and also uses that bag as a carry on for travel.
The bag goes right next to the shooting bench at the firing line. It presumably gets a decent amount of powder residue on it, and yet it's been swabbed several times and not set off anything. My buddy is scrupulously careful to remove anything non-airport-approved before taking it on a trip, so the fact that something "bad" was previously contained in the bag has been double/triple checked to be absent before they show up to the airport.
Heard similar stories from many people. I have my own--
I was at a range shooting this old revolver with worn seals. Every shot, unburnt (or sometimes burning) powder was flying backward onto my face and arms. I basically took a gunpowder shower.
Got up like 6 hours later and went to the airport to get on a plane. Got swabbed. Came back negative. Got on the plane.
So... yeah, not really sure what the swabs are doing. I have to assume it's more an issue of "they're not intending to detect that" than "failures to detect" because otherwise the repeated misses here are just a little too big to believe.