I just read an interesting write up on the PCC at americanrifleman.org. Noteworthy information in the article was the reason the barrel is flat where the rear sight is mounted, which I though was odd when I first saw photos of the carbine. They state that Ruger intends to offer a plate to replace the rear sight to mount the popular pistol size red dots like the RMR, Fastfire III, Sig Romeo, Leupold, and others. Pretty cool! Recommended reading. Bob!! :D