Oh, does our Constitution need revising, to come into line with the realities of the time. The Second Amendment was crafted in a time when the US was just forming and had no standing army, and almost had lost the revolution it fought against England. It was a time when the only defense available was the single shot, wildly inaccurate musket kept in most homes.
Today, American states have a National Guard, and of course it has the most powerful standing military in history.