By the way, here's a couple of arguments I'd like to see advanced, just in case any of y'all get a chance to argue such cases:
1. Cases that come up under this one, as well as the Lautenberg "gun free school zone" statute, are both subject to the same objection that was made earlier, and upon which the S.Ct. found the Lautenberg statute unconstitutional. The fact that Congress has added some language about interstate commerce don't make it so, because it is clearly not designed to have any effect whatsoever on interstate commerce.
2. The Second Amendment doesn't say, "subject to reasonable regulation", it says, "shall not be infringed". If your rights are subject to "reasonable regulation", then they're not rights. You either have your rights under the Constitution now, or they've already been taken away by acts of tyranny, which should be corrected immediately before things get worse.
3. An amendment to any document, unless limited by its own terms, amends the entire document. The Second Amendment amends the entire body of the original Constitution, including the power to tax and the power to regulate interstate commerce. Thus, regulation of NFA weapons using the taxation power is unlawful, and the statute under consideration in Castleman is unlawful - Congress can't get around one of the rights identified in an amendment by invoking the magic words, "interstate commerce", because that power has been amended.