Works fine, but a little dirty. Not a really good seal there for chamber. Will work better if you leave some length of the casing in tact to help seal your breech. If you are really into doing it on the fly though, the 12 ga. brass shells are only about 25 bucks a box and you can make a little block of wood to tap out the primer and tap in a new one. Then just load the brass shells the same way by hand. It's your call, but the system is pretty much the same as the old H&R slide in breech plugs. In an emergency situation, this would work fine though.
