This is exactly why I teach my daughters that *EVERY* time you pick up the gun, even if you just checked it a minute ago, if the chamber is closed, you check it again. My oldest is 7, so I joked with her about the "Magic Bullet Fairies". That "if you put the gun down, with the action closed, and turn your back, the Magic Bullet Fairy may have put a bullet in the gun while you weren't looking. So you check it again. " Those overlapping layers of defense, those good habits that help keep everyone safe. Yeah, I put it in a silly way for her, but it's those good habits that keep everyone safe. It needs to be automatic, ingrained. Just the other day I was at my LGS looking at a couple of handguns (had heard they'd gotten a Keltec P50 and wanted to handle it). Clerk takes the gun down from the wall, checks the chamber, hands it to me with the chamber closed. I automatically recheck the chamber. Because if he messed up and missed something, I AM RESPONSIBLE FOR WHAT HAPPENS WHEN THE [UNPRINTABLE] GUN IS IN MY [CENSORED] PAW!