personally, i have no use for these but certainly they are protected free speech ...and an interesting craft hobby for those who are interested and willing to shell out the big bucks for the necessary equipment...
ha! by now, probably every law school professor in the country has downloaded these for classroom teaching exhibits...
still, for any practical use... its a lot cheaper and easier to just buy a professionally-manufactured one at the store
Except, of course, that there is now an unknown number of completely untraceable firearms out there. That's a win for America whether or not either of us has one or more of those guns.