It seems the founding fathers wanted to put private citizens on a relatively even playing field with the government -- understandable considering they had just fought long and hard to free themselves from tyranny. Isn't the risk government oppression still very much a relevant issue today?
I don't get the technology argument at all. Technology certainly has advanced, but if everyone is armed with the latest technology, there's no relative difference from everyone being armed with muskets. Besides, it's simply not true that the only weapons in the late 18th century were single shot. The Girandoni Air Rifle
, actively used in the Austrian army for over a decade at the time the Second Amendment was adopted, had a 22 round magazine that could be emptied in about a minute. It even had usable accuracy (could place ten shots into a group the size of a quarter at 50 feet).