Yep, you’re right, M-16, M-4 is 5.56 (.223). I call BS on this whole story. When Obama falls he is going to fall hard as he says some of the most ignorant things you are likely to hear. The problem is, that right now, those listening and then believing what they hear are equally or even more ignorant. :)
Unfortunately, the ignorant are the majority now. Not a sunny picture. They only know one thing, they can vote themselves a raise at every election.