"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
If you're going to quote it, do so properly.
Here's a quick excerpt from Wikipedia's (surprisingly well documented) page on the subject.
In the twenty-first century, the amendment has been subjected to renewed academic inquiry and judicial interest. In District of Columbia v. Heller (2008), the Supreme Court handed down a landmark decision that held the amendment protects an individual right to possess and carry firearms. In McDonald v. Chicago (2010), the Court clarified its earlier decisions that limited the amendment's impact to a restriction on the federal government, expressly holding that the Fourteenth Amendment applies the Second Amendment to state and local governments to the same extent that the Second Amendment applies to the federal government. In Caetano v. Massachusetts (2016), the Supreme Court reiterated its earlier rulings that "the Second Amendment extends, prima facie, to all instruments that constitute bearable arms, even those that were not in existence at the time of the founding" and that its protection is not limited to "only those weapons useful in warfare". (minus the reference notation this is the text as of this posting)
However one wishes to define the 2nd amendment, the fact is that there are a stupendous number of firearms of numerous makes in circulation, with more being made all the time. And since the U.S. has two massive borders that cannot be effectively patrolled (and two gigantic coastlines) any attempt to stop their dissemination to those who want them is probably not going to work. I see no valid reason to attempt to do so either.
I don't own any firearms myself, but I really do feel that if Mr. Johnson down the street wants to own a minigun for whatever reason, then there is no reason he should not be able to do so, so long as he does not present a danger to himself or others, and has been trained in the use and maintenance of his weapon.