I first wrote this article intending it to be a comment on this thread at the Volokh Conspiracy. It grew so big and wandered 'through every room in the house', straying away from the specific topic so I decided not to inflict it on them. Instead, Samizdatistas are the lucky beneficiaries. Seriously, I presume most of you will skip it. That is fine. Here is the amendment as it appears in the US Constitution.

Amendment II

A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed.

In reading the Federalist Papers it appears obvious, at least to me, that 'the militia' and 'a well regulated militia' are two entirely different things. Hamilton clearly describes in #29 a great deal of commitment and training required to "acquire the degree of perfection which would entitle them to the character of a well-regulated militia" [my underscore] and speculates that for "the great body of the yeomanry, and of the other classes of the citizens" it "would be a real grievance to the people, and a serious public inconvenience and loss".

In #46 Madison calculates the number of "a militia" at 1/8 of the entire population.

The highest number to which, ... a standing army can be carried ... does not exceed one hundredth part of the whole number of souls; ... This proportion would not yield, in the United States, an army of more than twenty-five or thirty thousand men. To these would be opposed a militia amounting to near half a million of citizens with arms in their hands, officered by men chosen from among themselves, fighting for their common liberties, and united and conducted by governments possessing their affections and confidence."

Clearly Hamilton's "well-regulated militia" and Madison's "militia" are entirely different and together with the title of the New York statute that Eugene Volokh cites,"An Act for Settling and Regulating the Militia ...", suggests that the degree of regulation of the militia was a continuous scale.