They aren't metal detectors, so I doubt it was the gun. I set them off in every store for a year. It got quit embarrassing actually. Turns out I had a sticker like tag in my wallet that somehow got reactivated. I had a store run my wallet across their deactivation pad and the problem was gone, but a few months later it started happening again. This time I ripped the sticker out, which was hard because it was VERY sticky and deep down in one of those small pockets. I got most of it out and it has not happened since.