I compare the idea you seem to advance with the idea advanced in drug policy--that somehow the government can write and enforce a law that will eliminate certain drugs and their usage. Well, after nearly a century of such an effort, we have kids bringing the prohibited items to school, and/or selling them on street corners.
So if the government cannot stop drug use and eliminate drugs by legislation, how on earth do you suppose it can eliminate guns by legislation and enforcement?
Excellent response BR.
Even if the government were to place any ban on gun ownership it will not stop the illegal sales of firearms.
Heck, even though there are legal ways to purchase firearms in the US, there are still "illegal" ways to purchase them as well.