I wasn't able to find any information on these rings.
However, I do have a set of adjustable Barrett rings. They are TALL, from the top of the dovetail flat to the bottom radius of the ring is a close 1". The length of the rings are around 1.2", kind of long and the rings are aluminum with steel phosphate coated torx head cap screws. Four screws per cap, two screws for the vertical tilt/slope adjustment, and one crossbolt to lock the ring itself to the base. They do not come with 1" inserts and I think the rings have a 2 degree adjustment. Price runs $180 from Barrett, perhaps it will be cheaper if you know a dealer.
I have been thinking about getting some Barrett adjustable rings. How do you like yours? Do they allow you to use all of your internal elevation in your scope tube? Do they ever shoot loose? What scope do you have in the rings and what rifle is it mounted on and how big is the gap between the objective lense and the barrel?
I have a question about the height of the rings, I am a bit confused of what height the barrett rings are. I have posted a diagram of some ring measurements, the measurement I am looking for is from the middle of the scope tube to the flat that touches the scope base. Which is measurement "A" on the diagram. http://www.badgerordnance.com/img/pro/prod_chart.gif
Here is the Ivey adjustable in black. I am a dealer now and just have one ready to go in black. They are also available in High Polish which is going on my .408 in 2 weeks and a satin finish.
They are cut to extreme tolerances and as you can see, are locked with a set screw after set to appropriate height. The micrometer goes to the front and no elevation means that the front is all the way up.
They are $445 and normally require a 4-5 week wait since many finishes and many different types of bases are utilized.
Assuming they must calibrated for a certain spacing apart to be accurate, what distance is it and is it measured on center of at their maximum width apart? This would dictate what tubes would fit and what wouldn't. These are made to be used in conjunction with internal vertical scope adjustment or as a stand alone that would be more accurate?
distance from center of 30 mm tube to top of mount is .7 inches.
Spacing of feet is set at 4 inches for short action and 4.75 for long. A different cam goes into each one to give it a 50 MOA maximum.
As to the question as to whether these were meant to be more precise than internal scope measurements.....
They may just be, but that is not the intended use. They are meant to supplement internal use for those that need major elevation changes with finer adjustments made with the scope.
This allows you to keep near the center of an internal scope no mattter what the need. Could you make a 3 moa adjustment with the micrometer, absolutely. Keep a notepad handy, though!!!!
I will post a cross section drawing of the mount in a few minutes.