magic
The raceways are cut with a wire.
Picture a verticle bandsaw with a wire instead of a blade. Then it cuts with electricty under water. :confused: Don
The best way is to EDM the final little bit before you break thru. I drilled almost to the hole and then had my EDM guy finish it. For a standard .223 I would recommend a .104 hole. Don
The rings were purchased without dovetail, mounted on a 30 mm bar at the spacing shown and then the dovetail was machined.
It's probably not for everyone but Hey it's my damn rifle ain't it? Don