The SCOTUS does not add to or alter the US Constitution,....It only determines if a case can be heard and decides if a cease is or is not represented by that Constitution.
Sort of, I'm having a little trouble understanding what you're trying to say (sorry). SCOTUS is the final interpreter of the US Constitution, and decides whether or not a case is constitutional (in violation or agreement with the Constitution), and most importantly they get judicial review, where they get to review the actions of the executive and legislative branches. If that's what you were getting at, my bad.
But really, you can't argue that it's "without infrigment of the Right, no matter the firearm," because when it was written they had muzzle loading muskets, and not everyone could actually afford a musket. The Founding Fathers had no idea about machine guns, and I'm willing to bet that if a private citizen owned a cannon, they'd be against that falling under the purview of the 2nd Amendment. The most important thing is that when you look at the debate the US did not have a standing army so many thought militias would be important in protecting the United States (and each individual state). Moreover I highly doubt that they would expect semi-automatic rifles, handguns, etc. etc. etc..
This is actually one of the main reasons why sawed-off shotguns are not covered by the 2nd Amendment and require extensive regulations to get -- that 1st part of the 2nd Amendment. The Supreme Court ruled that a sawed off shotgun has no practical purpose in a militia, thus the effective "ban" on them was Constitutional. In
United States v. Miller the court found that "[a] shotgun having a barrel of less than eighteen inches in length" at this time has some reasonable relationship to the preservation or efficiency of a well regulated militia, we cannot say that the Second Amendment guarantees the right to keep and bear such an instrument." Which somewhat overturned
Presser v. Illinois when they said that the 2nd Amendment was not the right to form militias for a state, but the right of an individual. However in
District of Columbia v. Heller they once again asserted that it was a right of the individual.
The 2nd Amendment is a very tricky amendment and has been, historically, up for a lot of debate (even the debate to what the 2nd amendment was going to be had a lot going into it). However the quote that I was referring to in regards to Thomas Jefferson and his memorial is found on the southeast portico and is from a letter he wrote to Samuel Kerchval, "I am not an advocate for frequent changes in laws and constitutions,
but laws and institutions must go hand in hand with the progress of the human mind. As that becomes more developed, more enlightened, as new discoveries are made, new truths discovered and manners and opinions change,
with the change of circumstances, institutions must advance also to keep pace with the times. We might as well require a man to wear still the coat which fitted him when a boy as a civilized society to remain ever under the regimen of their barbarous ancestors."
