I think you might have missed the point of my question. I am not suggesting banning ammunition, but asking why legislating their killing power be restricted as an approach to gun-control has not been tried. It appears that it is constitutional to limit the killing power of ammunition (i.e the armor piercing bullets) - what interests me is how far this approach can be taken and still be constitutional.

I will say once again I am not personally in favor of gun control, just asking why the anti-gun lobby is not trying to go after the weak point in the regulation of guns (the ammunition) rather than the strong (the second amendment).