[JamesP81]

Cannon and such larger weapons are more properly classified as "ordnance". I think the founders knew the difference and had they meant something beyond the "arms" of a soldier they'd have said it.

Unfortunately, history doesn't exactly support this view. As I mentioned in a previous post, there was once something called a privateer. A privateer captain owned his own ship, and armed with his own weapons which included smoothbore cannon.

[Ramius]

Oh, yes of course. There were privately owned cannon, and more to the point I don’t think there is anything suggesting an early move by any legislature to outlaw them (which is interesting all by itself).

But it wasn’t common practice for households around the colonies to have their own cannon or other heavy ordnance. What they did all have were personal arms— and that is what the founders were specifically attending to... That freedom depends on the rank and file citizen to have the means to fight. I think they meant it as a starting point, the essential minimum for the formation of a militia, and left silent any discussion of heavier weaponry.