The pointed rods will get you close, but not always exact. The points may touch, but everything is not neccessarily in perfect alignment. I use a gizmo that started out as a piece of ground and polished shaft stock( 1" and 30mm) about 3" long, chucked up and centered in the lathe and bored completely through with a 5/16" hole. The shaft stock is now cut in half and the hole through the middle is chamfered on both ends. The outer corners of both pieces are dressed to remove the sharp edges.
One piece is placed in each scope ring and snugged up. Now a piece of 5/16" drill rod is inserted into one end of either piece of shaft stock, if it slides easily through both halves in each ring without binding, your rings are now in perfect alignment. If the drill rod binds going into the second ring, you need to lap the rings with one of the bars with a handle with some valve grinding compound.
Lap both rings until you get a non binding pass through with the drill rod.
Dave Manson and others(Clymer,etc) make a reamer for scope rings for around a hundred bucks, a turn or so with one of these and your rings will be dead nuts to each other.
F1