I've got a chance to pick up a Ruger MarkII Target rifle on a swap. This has the integral bases machined into the receiver. My concern is that there might not be scope rings to give me an offset to get the most range out of my scope. I'm looking to angle my scope down 20-30 minutes of elevation so I can use more of my turret adjustment for long-range shooting. Does anyone make offset rings for a Ruger rifle?