Mr. Blunt and Cranky has this crazy theory, and it goes like this: the Founders were smart people who argued, haggled, debated, and In the end wrote a Constitution that said exactly what they meant. Nothing more, and nothing less. And if we don’t like something, we can bust our arses and amend it. (Yeah, a crazy notion,eh?)
But when people read the Constitution, they cherry-pick the bits and bobs they like and pretend the rest is not there, or that “the Founders were just kidding with that part”. That is not the act of a law-abiding citizen, folks. No matter if one is a Supreme Court justice or some regular schmuck, we have to respect the entire law. Including the Second Amendment.
People love the second part of the sentence, yes they do. But the first part, about the “well regulated militia”? Even Fat Tony and his posse at the S.C. tend to gloss over that bit.
The only reason to have battle-specific weapons is to fight a battle. And the only smart way to fight a battle is in an organized military group. For that matter, it is the only legal way to do it. So if you’re not in such an organization and you own and use military-style armaments, you are not in compliance with the law of the land.
Don’t like it? Pursue an amendment. But until you get one, just obey the friggin’ law.
Mr. B & C
bluntandcranky 
I suggest you read Miller V US…maybe some of Founders thoughts on why citizens should have guns, specifically :
“No free man shall ever be debarred the use of arms. The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government”
— Thomas Jefferson, 1 Thomas Jefferson Papers, 334
“Americans have the right and advantage of being armed – unlike the citizens of other countries whose governments are afraid to trust the people with arms.” (James Madison, The Federalist Papers #46 at 243-244)
“…but if circumstances should at any time oblige the government to form an army of any magnitude, that army can never be formidable to the liberties of the people, while there is a large body of citizens, little if at all inferior to them in discipline and use of arms, who stand ready to defend their rights…” (Alexander Hamilton speaking of standing armies in Federalist 29.)
“Besides the advantage of being armed, which the Americans possess over the people of almost every other nation. . . Notwithstanding the military establishments in the several kingdoms of Europe, which are carried as far as the public resources will bear, the governments are afraid to trust the people with arms.” (James Madison, author of the Bill of Rights, in Federalist Paper No. 46.)
“I ask, sir, what is the militia? It is the whole people, except for few public officials.” (George Mason, 3 Elliot, Debates at 425-426)
The best we can hope for concerning the people at large is that they be properly armed.” (Alexander Hamilton, The Federalist Papers at 184-8)
That the said Constitution shall never be construed to authorize Congress to infringe the just liberty of the press or the rights of conscience; or to prevent the people of The United States who are peaceable citizens from keeping their own arms…” (Samuel Adams, Debates and Proceedings in the Convention of the Commonwealth of Massachusetts, at 86-87 (Peirce & Hale, eds., Boston, 1850))
“Firearms stand next in importance to the Constitution itself. They are the American people’s liberty teeth and keystone under independence … From the hour the Pilgrims landed, to the present day, events, occurrences, and tendencies prove that to insure peace, security and happiness, the rifle and pistol are equally indispensable . . . the very atmosphere of firearms everywhere restrains evil interference – they deserve a place of honor with all that is good” (George Washington)
And the Constitution says what it says. That is the law of the land.
To amplify: the source materials are not the Constitution. If people had agreed upon these other documents, they would have made into the final version. But they did not.