Except that it is a tactic, not an objective. The objective is to keep people from owning machine guns.
I don't recall a nationwide machine gun confiscation program.
The objective of the federal law is to prohibit the interstate commerce of machine guns. When people like Bob Stewart (and others) manufacture homemade machine guns, it interferes with Congress' ability to regulate.
I'll ask you the same questions that I asked publiusF27. Maybe you think Congress shouldn't be regulating machine guns. Maybe you think that those who are (21?, 18?, 16?, any age?) have the right to go to Wal-Mart and buy a full-auto MAC-10. And maybe you think the second amendment protects this right. Fine. Then I can understand why you believe that Congress is overreaching.
But, IF you believe that Congress may regulate the interstate commerce of machine guns, then you must concede they also have the power to regulate those activities that interfere with them doing that. Pure and simple.
In the Stewart case, you can play these wink-wink, nudge-nudge games from here to Sunday -- you can say "but they're for his own use, you have no proof" all day long, but a reasonable person would say those five machine guns were for sale, especially considering the fact that he was engaged in the unlicensed sales of other unassembled guns to the general public.
So, it comes down to "Should Congress be regulating machine guns or shouldn't they"? You can't honestly say "yes" and then allow every Tom, Dick, and Bob Stewart to build them in their basements.