The Waffenfabrik von Dreyse was founded around 1841 to manufacture the famous Dreyse Needle gun for the Prussian Army, and they also made needle-pistols and caplock revolvers.
A superposed load or stacked charge is a method used by various muzzleloading firearms, from matchlocks to caplocks, as well as newer Metal Storm weapons, to fire multiple shots from a single barrel without reloading.