Anyone out there have a CZ 550 in .338 Lapua. The specific caliber is not important; anything that heavy or heavier would probably present the same problem, which is, I cannot find anything but single screw (per side)Leupold rings that fit the odd size built in mounting feature of this rifle. It is basically the same as a narrow Pickatinny rail,, but too narrow to take rings designed for the rail. I have e-mailed multiple ring makers and get the same answer. I have the same problem on my Sako chambered for the Lazzeroni Warbird. I put six screw Blackhawks on my .338 RUM, and they work great as they did on my Mark V 30-378. Any suggestions would be appreciated. Thanks.