Nikon makes the p-223 & m-223 series which are good. I have a fixed 6X power from primary arms that is made for the .223. I really like it.
"No free man shall ever be debarred the use of arms. The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government"
-- Thomas Jefferson, 1 Thomas Jefferson Papers, 334