TITLE 10 > Subtitle A > PART I > CHAPTER 13 > Sec. 311. describes the federal militia, not the well regulated state militia to which the second amendment refers.
Title 10, Sec. 311 is the modern-day descendant of the 1792 Militia Act, which discussed the "militia" as almost all of us understand it to be (i.e. all able-bodied males, or at least those of us between 17 and 45). There is, to my knowledge, no such thing as the "federal militia."