The whole point of the design of the Napoleon was to have a howitzer that would perform the function of a cannon, i.e., firing shells & direct fire. That way, as is seen in the U.S. Civil War, there was no need for a battery to have separate howitzers & cannon. Walking the gun line & explaining the design & function of the various pieces is regular part of our battery programs at Stones River. The evolution that involved melting down the 1841 howitzers & cannons in order to recast them as Napoleons is one of my things. The 1841 cannon could not fire shells because the bore was too small. The 1841 howitzer's chambered breech meant that it was underpowered for direct fire. Six Napoleons gun/howitzers packed an exponential increase of firepower over a mix of six cannons & two howitzers. I don't know anyway to explain it more clearly than that.