A couple of weeks back, I took 6 pellets out of an HW 100, and that wasn't the first one I've seen. If the cylinder isnt tight, it will multiload. It's also possible to jam the mag in backwards, it wont work, but I've seen it done. Coincedently, half an hour later, I did the same with a BSA..... Magazines are the invention of the devil..!
Gus