Hey H, glad to see you in the local forums finally! For anyone who doesn't know, I have one of Constructor's 6.8x43mm "recon" profile 16" uppers and it shoots sub-MOA off a bipod with a cheap red dot sight. Great craftsmanship and a final product that I would trust my life to without question if need be. For any high quality AR upper in 5.56, or 6.8, I highly recommend www.AR15Performance.com