Some thoughts on Heller, RKBA and "military-style" small arms
In Heller, the Supreme Court stated that the intent behind the 2nd Amendment, and the relationship between the prefatory clause and the operative clause, is as follows:
"First, of course, it is useful in repelling invasions and suppressing insurrections. Second, it renders large standing armies unnecessary-an argument that Alexander Hamilton made in favor of federal control over the militia. The Federalist No. 29, pp. 226, 227 (B. Wright ed. 1961) (A. Hamilton). Third, when the able-bodied men of a nation are trained in arms and organized, they are better able to resist tyranny."
"We reach the question, then: Does the preface fit with an operative clause that creates an individual right to keep and bear arms? It fits perfectly, once one knows the history that the founding generation knew and that we have described above. That history showed that the way tyrants had eliminated a militia consisting of all the able-bodied men was not by banning the militia but simply by taking away the people's arms, enabling a select militia or standing army to suppress political opponents." (By “select militia” they refer to something along the lines of the modern-day National Guard, which is different from the “organized militia.”)
"This holding [in Miller] is not only consistent with, but positively suggests, that the Second Amendment confers an individual right to keep and bear arms (though only arms that "have some reasonable relationship to the preservation or efficiency of a well regulated militia")."
"In the colonial and revolutionary war era, [small-arms] weapons used by militiamen and weapons used in defense of person and home were one and the same."
The stated goals of the 2nd Amendment simply cannot be accomplished with a limited array of deer rifles and shotguns, but they can with military-style small arms and some malicious ingenuity, as various insurgencies around the world have amply demonstrated. And it is not true that the Founders did not contemplate more lethal weapons - they certainly had cannons in the late 18th Century, which were the state-of-the-art in weapons of mass destruction, and those are STILL legal for private citizens to own. It is only in the 20th Century that government began imposing restrictions on what types of arms citizens could possess.
Additionally, the Supreme Court’s interpretation fits with the statutory scheme of the Bill of Rights, which was designed to protect citizens from their government rather than from each other. The 1st Amendment keeps government from restricting our speech or religious practices. The 3rd Amendment prohibits government from taking over our homes. The 4th Amendment prevents government from searching and seizing our possessions without due process of law. The 5th Amendment restricts government from prosecuting us without due process of law. The 6th Amendment ensures that government cannot imprison us without a speedy trial by our peers. The 7th Amendment prevents government from doing away with our right to jury trials in important civil matters. The 8th Amendment protects us from government using cruel punishments against us or holding us without bail. The 9th Amendment prohibits government from usurping any of our rights not specifically listed, and the 10th Amendment keeps the federal government from taking away power from the states and the people. It seems clear then that the 2nd Amendment was not primarily designed to protect us from each other or to ensure our right to hunt for food, but was instead a check upon the powers of the federal government. Such a check requires the ability to resist that power if it becomes necessary, and the 2nd Amendment ensures that ability by providing the Bill of Rights with tooth and claw.