I am amazed at how many people, especially the media, do not understand what the Second Amendment is all about. It is not about guns, it is about freedom from a tyrannical government.
Our framers lived under such a government and the only way they were able to get out from under it was by forming militias whose members had their own guns. There was no United States government, or Army at that time, to fight against the British Army. Of course the British considered these people radicals and needed extermination, much as the tea party is perceived today by many members of Congress, media, liberals, etc.
The words “a well-regulated militia” does not mean it is already formed. It means when the time comes to form such a militia against the government by ordinary citizens that they will have their own weapons to use.
How much firepower a weapon has is meaningless, and has nothing to do with the Second Amendment. It started with rocks and clubs and has progressed to today’s standards, which would be needed in case of a tyrannical government, which is what the Second Amendment is all about.