I have a Redfield 2-7X (made by Leupold) on mine. It fits the compact rifle well. Doesn't shoot very well with anything. Bore slugs .3105". Tried both bullet diameters and many powders. Also installed a reduced diameter gas bushing to calm it down. Fire-lapped the barrel in an attempt to make the diameter more uniform. Going to try barrel tuning weights next since that made a big difference on my friend's. My Ruger American in 7.62X39 is a tack-driver.