Some limitation on the types of arms protected by the second amendment is clearly within the scope of the amendment. Mr. Justice Scalia in the Heller decision:
There seems to us no doubt, on the basis of both text and history, that the Second Amendment conferred an individual right to keep and bear arms. Of course the right was *not unlimited*, just as the First Amendment ?s right of free speech was not, see, e.g., United States v. Williams, 553 U. S. ___ (2008). Thus, we do not read the Second Amendment to protect the right of citizens to carry arms for any sort of confrontation, just as we do not read the First Amendment to protect the right of citizens to speak for any purpose. [...] Like most rights, the right secured by the Second Amendment is *not unlimited*. From Blackstone through the 19th-century cases, commentators and courts routinely explained that the right was not a right to keep and carry *any weapon whatsoever* in any manner whatsoever and for whatever purpose. [emphasis added]
You may think the right *ought* to be unlimited, but as a matter of text, history and interpretation, it is not. That is simply a fact, and crazed far-right gun crackpots are going to have to accommodate themselves to that fact.