So, as I understand the interpretation of the 2A, it is designed to allow all citizens to own and maintain arms, with the ultimate intent to, if needed, enable the formation of a militia to overthrow an ill-willed government once again, as was done during the Revolution.
I disagree with this interpretation. The militia really played a rather small role in the American Revolution, and it was the Continental Army which really threw off "an ill-willed government." The militiamen were, generally speaking, unruly, undisciplined, illequiped and unprepared for war. They would leave in the spring for planting season (the best time for military campaign), and would follow State aims rather than national goals. This same problem often occurred during the War Between the States, when individual state Governors would often recall their soldiers to protect their state, at the expense of the national goal of protecting the Confederacy.
Stepping back, one of the founder's biggest fears was a standing army (E.g., "He has kept among us, in times of peace, Standing Armies without the consent of our legislatures." Declaration of Independence). They were concerned that a large national army would be expensive to maintain, antithetical to the interests of the nation as a whole, serving the interests of the larger states like Virginia and New York over those of the smaller states, and could be co-opted by Generals or Presidents in a reach for power.
The 2nd Amendment is not the only location in the Constitution where the militia is mentioned. Article 1, Section 8, Clauses 15 and 16 state, respectively: "[Congress shall have the power] to provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions; To provide for organizing, arming, and disciplining, the Militia, and for governing such Part of them as may be employed in the Service of the United States, reserving to the States respectively, the Appointment of the Officers, and the Authority of training the Militia according to the discipline prescribed by Congress."
Pulling this all together, the militia is designed to strike a very careful balance between a large standing armies, and being defenseless. By ensuring that a militia exists which can be called forth as needed (as in the War Between the States, WWII, Korea, and the war in Iraq and Afghanistan, and certainly others. These are just the instances I am aware of), it becomes duplicative and unnecessary to have a large standing army. The militia remains in the hands of the States when not in service of the national government, helping to ensure that the militia not become a national tool against liberty, or too expensive.
Nowhere does it say, imply, or hint that the founders had in mind a militia designed to overthrow the government they had just created. Rather, the militia is to "suppress insurrection and repel invasion."
While a well-regulated militia is necessary to the security of a free people, it is not a tool to overthrow the national government. It is not designed to be the insurrection which it is supposed to put down. The militia acts as security for free people by preventing the need for large standing armies in times of peace. It develops a certain level of preparedness during times of peace which is not under the control of the national government, and which simultaneously prevents us being caught off-guard when the peace loving nation of the United States is unwillingly forced into war.
Now, I read the 2A as granting an individual rkba. While State's do have vast powers over the militia, they cannot take away an individuals right to keep and bear arms, as that would effectively eliminate the (armed) militia, thereby subverting the entire premise of the 2A.
What arms does this allow us to keep? I can't really answer that. But it may help to reframe the question along what I feel are historically and legally accurate grounds.
This thread is largely focusing on what tools we should use to fight our own soldiers (largely ignoring the fact that many of these soldiers are members of this board, as well as our friends and family). Instead, ask yourself during what kind of scenario would your state or national government call forth the unorganized militia (i.e. all men (perhaps women) of military age (18 - 35?), not in the National Guard or other division of the Armed Forces). Perhaps fighting invasions or insurrections. Perhaps facing natural disaster that overwhelmed existing government forces. How can we, as individuals knowingly a part of the militia, best prepare for that emergency? Is it only guns that we need?
"If a well-regulated militia be the most natural defense of a free country, it ought certainly to be under the regulation and at the disposal of that body which is constituted the guardian of the national security. If standing armies are dangerous to liberty, an efficacious power over the militia in the same body ought, as far as possible, to take away the inducement and the pretext to such unfriendly institutions. If the federal government can command the aid of the militia in those emergencies which call for the military arm in support of the civil magistrate, it can the better dispense with the employment of a different kind of force. If it cannot avail itself of the former [i.e., militias], it will be obliged to recur to the latter [standing armies]. To render an army unnecessary will be a more certain method of preventing its existence than a thousand prohibitions upon paper." Federalist No. 29.
