While I agree with the underlying sentiment -- if the 2A protects any guns, it is those military pattern ones -- the italicized text in the OP contains some errors. (Also, is original by the OP author? If not, a link to its source would be nice).
"Sawed off shotguns" were not
banned by the NFA of 1934. Shotguns with a barrel length less than 18 inches and involved in interstate commerce were required to be
registered and
taxed. Miller and his companion were caught crossing a state line with a sawed off shotgun; given Miller's criminal history, it was a good guess by the police that they were on their way to a robbery, but there was no evidence for that, so they were charged with possession of an unregistered/untaxed shotgun of less than the required dimensions.
There were many Federal officials and politicians that would have been happy to ban pistols (which were included in the original drafts of the NFA), short shotguns and short rifles, and machine guns, all with the justification that "only criminals use these." (Sounds familiar, doesn't it). However, they hadn't worked themselves up to completely ignoring the Constitution and the Commerce Clause yet, so they settled for trying to tax them out of existence, which darn near worked.
I have run across a couple of interesting (to me anyway) resources on the
Miller decision. At this link:
http://rkba.org/research/miller/Miller.html" onclick="window.open(this.href);return false; there claims to be a transcription of every legal document associated with the case.
There is also this paper:
THE PECULIAR STORY OF UNITED STATES V. MILLER by one Brian L. Frye, writing in the
NYU Journal of Law and Liberty. I have no idea who he is, other than a lawyer, nor had I ever heard of that particular journal.
However, he advances an explanation of the case that I have never heard before, but sounds terrifically plausible, especially as I get older and more cynical about the practice of law and government.
He makes a pretty good case that the Government recognized this was an excellent opportunity to get SCOTUS backing for the NFA, which was being challenged in various jurisdictions as unconstitutional. Miller was not sympathetic defendant, and the political history, known inclinations, and actions of the district court judge indicate he may have colluded with others to turn this case into a vehicle for doing so. Although the defendants were ready to plead guilty, the judge refused the pleas, gave them a pro-bono lawyer, and immediately quashed the indictments on constitutional grounds (altho as Democrat representative and FDR supporter in Congress, the judge had pushed hard for gun severe gun control measures -- he was appointed to his judge position by FDR).
The DA was able to get the case appealed directly to the SCOTUS, bypassing the Circuit Court, and Miller's lawyer never seriously participated in Miller's defense again -- he did not submit any written arguments and did not go to oral argument, pleading lack of funds, and suggested the the SCOTUS hear the case solely on the Government's arguments. Note also that Miller's lawyer was immediately appointed to fill an unexpired state senate term after the indictments were quashed, and that Arkansas was virtually a one-party (Democratic) state.
So the DA and the FDR government got what it wanted out of the case, which was SCOTUS backing for the NFA, and everyone lived happily ever after. See Frye's paper for what happened to all the players.