Seriously, though, I do not think the founders envisioned a world where common foot soldiers are touting full auto AKs, Uzis, M-16s, M-60s, RPKs, etc. etc. etc.
What the common foot soldier carries should be available to the U.S. militia - meaning everyone according to the 1780 definition of militia.
Not to mention, where is the harm of law-abiding citizens having the firearms they desire? Because you are scared of the idea? Too f'n bad for you. Let's join the totalitarians because you don't think the founders foresaw auto firearms! Since when is the lack of the founders' clairvoyance an excuse to limit freedom?
(Clue: what the founders DID foresee is the dangers of a government having a monopoly, or near-monopoly on military power, regardless of the level of firearms used. When they were through setting up the Republic, people could own personal cannon, complete with every type of shell available at the time. No one had a problem with that.)