Lawdog, I'm using Warne Maxima mounts on a couple of Ruger 77's I have. They are the strongest set-up I've come across so far. I put a lot of rounds through my rifles (.338WM and .450M) and the Warnes take the pounding. They are a vertically split ring which I like, but not all do. I usually get them from Brownells, but they can be ordered direct from Warne(who will charge full retail). Cabelas also has a small selection.