MedicineBow, you're always welcome to disagree, but bear a couple of facts in mind:
1) The 200M number includes every firearm purchased before 1968 that is still out there and was transferred, inherited, etc.
2) There are significant restrictions that many of us (myself included) don't think about simply because, in our memory, they've always been in place. Machine guns, suppressors, interstate shipping, etc.
3) As it stands, the first buyer for every firearm in the US requires a NICS check.
Compare this to, say 1920, when a 10-year-old could have ordered a machine gun through the mail and had it delivered to his home.
I'm a lawyer, but I'm not your lawyer. If you need some honest-to-goodness legal advice, go buy some.