the federal government is nowhere in the Constitution granted authority to abridge, restrict, or infringe, in any fashion whatsoever, guns, ammunition, etc. Thus, ALL such restrictive laws made by Congress, and ALL regulations made by the Bureau of Alcohol, Firearms, and Tobacco (ATF), are unconstitutional as outside the scope of the powers granted to Congress and to the Executive Branch by our Constitution. Restriction of arms and ammunition is NOT one of the enumerated powers delegated to Congress or the Executive Branch.
Furthermore, all pretended regulations made by the ATF are also unconstitutional as in violation of Art. I, Sec. 1, U.S. Constitution, which vests ALL legislative powers granted by the Constitution in CONGRESS. Executive agencies have no lawful authority whatsoever to make rules or regulations of general application to The People!
In addition, the President and the Senate may not lawfully by treaty do anything the Constitution does not authorize them to do directly. Since the Constitution does not authorize the federal government to disarm us, the federal government may not lawfully do it by Treaty. See,
http://publiushuldah.wordpress.com/2009/09/19/the-treaty-making-power-of-the-united-states/An ex post facto law RETROACTIVELY criminalizes conduct which was not criminal when it was done.
Say you barbequed outside last Sunday. That was lawful when you did it. Next month, Congress makes a pretended law which purports to retroactively criminalize barbequing outdoors. So, now, what you did is a crime (for which you are subject to criminal prosecution); even thou when you did it, it wasnt a crime. That is an ex post facto law.
Now, say Congress passes a pretended law making possession of firearms a crime and ordering everyone to turn in their guns. Only if you do not turn in your guns will you have committed a crime. That is not an ex post facto law because if you turn in your guns, you wont be criminally prosecuted. The crime is the failure to turn in your guns not the prior possession of guns.
Such a law would be totally UNCONSTITUTIONAL, because gun control is not one of the enumerated powers of Congress. Thus, the law would be outside the scope of the powers delegated to Congress.
It would also be unconstitutional as in violation of the 2nd Amendment.