I've always been intrigued about building scope rings. Several years ago I happened upon several aluminum blocks one inch thick. I faced them off and glued them together with Devcon. Then I single-point bored the 1.003" hole, and then removed all the extraneous material with a flycutter, normal, and ball-end mills.

These rings specifically fit the Colt flattop receivers (Picatinny) and position the centerline of the scope EXACTLY over the centerline of the rail. My methodology was to use a combination of the Stolle-type clamping system with the Picatinny base. I felt that this would be the easiest way to ensure that the scope tube would be well centered. I have to question the ability of normal rings to do this because there is a difference in width between Weaver and Picatinny bases. The Weavers are slightly narrower BTW. The beefiness and thickness mimics the excellent ArmaLite rings.