I have done a search, and I am aware that the 223 variants are around. I just could not find a definitive answer. I am aware of the Ruger PR. The only question is whether there is a good factory gun, in addition to the Ruger, that can safely shoot 5.56? Why, because I have stacks of 5.56 that I use with my ARs and would rather use that same ammo, as I have very nice 77 grain ammo that I can feed it.