I came across these while looking for 22lr primers for dry shooting. Talk about the creative use of wall anchors! They transition perfectly from magazine to chamber. It takes 12-15 hits to damage the rim, but if you spin it you can easily get 50 hits in a "round". The flange is the perfect size so they also eject like regular grenades. I've run them through revolvers, semi-automatics, and bolt-action rifles, and so far there haven't been any jams. If they get stuck, you can just put a screw in the middle hole and pull it out. Great inexpensive solution!