Back in the mid-60's I swore an oath (several times) to protect and defend the constitution of the United States against all enemies foreign and domestic. Even though I was pretty young, I took that oath very, very seriously. I still do. However, I never dreamed that domestic enemies would become so numerous, either because of fear, ignorance, or stupidity or some other factors. Unlike many of our countrymen I've read that document from the very first word to the very last word at least a dozen and a half times. Over the years, I believe I have seen that document subverted and misinterpreted by the courts, and others, several times.
As an American, one should not get to pick and choose which parts of the constitution one intends to support and defend. Nor, should an American tolerate or allow anyone to reinterpret what the constitution's intent "really" means in this 21st century without a "fight." The constitution means today, exactly what it meant when it was ratified by the original 13 colonies. Either that, or like George Orwell's "Animal Farm" or "1984" it means whatever someone else says that it means! If that is to be the case, then so many of us have/had been tricked into taking a meaningless and worthless oath!
Either the 2nd amendment means that we the people have the right to keep and bear arms as it meant for the first 200 years of our republic, or it never meant that at all--despite what the founding fathers believed and intended in there writing of that amendment, their personal letters/correspondence with each other, and in the set of Federalist Papers they published. Arguments over what is meant by "the militia" are meaningless, since the "right of the people to keep and bear arms..." trumps any other interpretation.
Now having said all that...I don't believe that "we the people" were ever intended to "keep and bear arms" like the artillery of 1700's or the armed vessels of that day. I don't think it is unreasonable to accept that the amendment did not intend to include weapons (i.e., cannons) that were part of the organized militia or the then infant Army of the United States. It follows further that the 2nd Amendment never did intend military grade weapons, i.e., AK-47's, M-15's, M-16's, 60mm/81mm mortors, howitzer, tanks with operational heavy weapons, etc. to be in the hands of "the people."
If we honestly and fairly think through the 2nd Amendment issues, it becomes clear that "we the people" were never intended by the founders to own and operate our own arsenals.