Reports on this have been uneven. I go to a number of meetings and conferences that include live fire of weapons, and many of the people that attend these portions shoot firearms regularly, anyway. I've asked them if they've ever been "caught" by the puffer machines, and they told me that they are seldom, if ever, stopped at the checkpoint after going through the puffer. This is explainable several ways, such as having changed clothes and showered between the last shoot and the checkpoint. But most of these folks handle their firearms and/or the cases during packing, so one would expect there would be some residue transfer.

I was traveling with my firearm in the approved case within a checked bag, and one zealous TSO decided that merited some extra inspection of my bag. Okay with me, check away. He decided to have me open the locked gun case, whereupon he swabbed the revolver itself and put the pad into the scanner. He seemed alarmed when he told me it was positive for explosive residue. I replied, "It's a gun. What did you expect?" He called his supervisor, who told him to lock up the case and send it through.