My cousin, a cop in West Sacramento, sent me a link to a video about a high speed pursuit involving a high powered rifle/carbine. I haven't been reading this thread for about a week now, so if it has already been brought up, my apologies. Regardless, in one of the last frames of the video, you see an LEO slinging an AR-15/M-16. FWIW.
Books.
http://xpstream.winisp.net/marcbarton/timgree