Exactly right Nick!

Mike, yes, I do think it is a distinct possibility that the Feds could outlaw automatic weapons and come to each previously legal owners' house and confiscate said weapons. Unfortunately, the Federal Government of the United States of America has already begun the process of regulating automatic weapons out of existence. Don't believe me! Check it out for yourself:
1.) The 1934 NFA Act, which regulates the sale of automatic weapons to this day, by imposing a $200 transfer tax. This is the first regulation of automatic weapons and one of the first compromises of the Second Amendment.
2.) The 1968 Crime Law, which further regulated firearms at the Federal level. Among other things, all automatic weapons had to be registered, in order to be considered legal, for the first time in our nation's history.
3.) The 1986 Federal Law Enforcement Protection Act, made it illegal to manufacture new machineguns, for civilians only. It also forbid importation of any, and all, parts for machineguns, for civilian owned guns only. This, in effect, says, "machineguns for police and government military forces are
good, but machineguns for civilians (ordinary citizens) are
bad"!

And who made this value judgement? Your Senators and Representatives in the Federal Government. I believe President Reagan signed this into law, as his veto would have been overridden anyway.
4.) The 1994 Crime Bill, which outlawed certain 'assault weapons' and large capacity (over ten rounds) magazines, again, to apply to civilians only!

Due to past precedent, the Feds could very easily wake up some sunny morning and quite legally take away your right to own a machinegun completely. And yes, they would come to your door to take them away. Don't forget about Randy Weaver losing his wife, child and dog, all because the Feds determined he was such an incredible danger to the public, all by himself, on that mountain top (Ruby Ridge). This was so because, after repeated attempts by the Feds to entrap Mr. Weaver into making and selling a sawed-off shotgun, he finally gave in, due to financial need. Some would argue that they (the Feds) are a fraction of a vote away from doing so already. All of this, inspite of the fact that all of these laws totally contradict the Second Amendment to The United States Constitution.

Regards, Walter