This version is impractical for a number of reasons, the first being that you have to replace the barrel to reload. There used to be matchlock rifles that literally had a sliding lock and trigger mechanism, which would align with three or four flash-holes on the barrel. The shooter started and the front and worked back, firing the stacked charges just like in this new version. Once in a while, some combustion gas would leak rearward and *all* of the charges would detonate at the same time. I hope Metalstorm has world-class insurance; they're marketing a high-tech pipe bomb.