What I would suggest, though, is just building your own AR from parts purchased off of Brownells.com. The AR platform is so easy to do this with, and it makes for a fun project. I have two RR's, but I just built a 300 BLK on a .223 AR platform, and that is the way to go IMO. Brownell's has some really cool features on your website that allows you to custom build your gun with all the different part options. It is a little intimidating, and you might need some assistance along the way (like when you are mounting your barrel on the receiver), but it is worth it.