The point is, when the bill of rights was written, atomic bombs weren't an apple in anyone's eye, and the second amendment doesn't account for the possibility.
I don't think atomic weapons are protected under the Second Amendment either. The very definition of "arms" as the Founding Fathers meant it to be was to protect any hand-held weapon. Rifles, pistols, swords, anything that is designed to be hand-held, was meant to be owned my the public.
