Anyone have any experience with a Ruger AC556? My brother is considering buying one from a friend and he has asked me what I thought. The details that I know is it is a factory folding stock with a 3 position selector(semi, burst and full) and a 12 inch barrel it is blued. My only experience is with a Mini 14 so I submit to any experts on this weapon. He can buy it for 5K which seems like a good price from what I can find on the web