That is a reference to United States v. Miller, 307 U.S. 174 (1939), which can be found here: United States v. Miller.
The case is very far from being a gun control freak's license to regulate our weapons possession. The case upheld a law against individuals possessing sawed-off shotguns, but only because they were not military weapons. Among the significant things it says are these:
The signification attributed to the term Militia appears from the debates in the Convention, the history and legislation of Colonies and States, and the writings of approved commentators. These show plainly enough that the Militia comprised all males physically capable of acting in concert for the common defense. "A body of citizens enrolled for military discipline." And further, that ordinarily, when called for service these men were expected to appear bearing arms supplied by themselves and of the kind in common use at the time.
Actually, the anti's misconstruction of Miller is worse than that. Contrary to their common claims, the Court did not uphold the conviction of Miller (nor co-defendant Layton). THESE MEN WERE NEVER CONVICTED!
The bottom line, literally, on the Miller decision was that the case was remanded to the lower court. The Supreme Court justices didn't say that a sawed-off shotgun wasn't a militarily-useful weapon, but rather that they could not themselves make that determination; it would be up to the lower court to do that.
When the Miller decision was handed down, neither Miller nor Layton was under indictment on the NFA'34 charges. Consequently, they were under no obligation to present a case, and they didn't. By the time the case was decided, though, Miller was dead and Layton was in jail on other charges. The government, rather than seeking to prosecute Layton, plea-bargained for time served.
In short, what happened is that the government's lawyer argued before the court that they could show Miller/Layton's gun was not of a type covered by the Second Amendment and the Court ruled that they could try to make their case in trial court. The government, after having been told that they could proceed with the case, probably recognized that it couldn't win (sawed-off shotguns were used in World War I, after all) and for all practical purposes dropped the charges and declared victory.
Take a look at sawed-off entry guns of today...
We note further that military weapons in 2002 include tanks, APCs, C-4, F-16s, B-2s, aircraft carriers, etc. Put that in the Miller decision and see what the USSC actually meant.
And even a sawed-off shotgun could be useful militarily, in fighting a guerilla war. But in 1939, we weren't fighting one (officially, anyway).
For freedom,
Locke