I did a search but couldn't find what I was looking for. And, due to differences in ring spacing, etc., I know there is not an EXACT answer, but about how much elevation in MOA will I gain using a + 20/-20 ring insert in the Burris Signature (1") Rings?

If you use a +20 /-20 set in just one ring and a set of zeros in the other you'll pick up approx. 20 moa . If you use a +20/-20 set in both rings you'll pick up approx. 40 moa. It's been my experiance with five different sets of rings that you usually wind up with a little less since the inserts are in thousandths not true moa. Chris

To find the exact MOA you will have you need to do the following: Front insert used + Rear insert used x 3600 divided by the ring spacing in inches will give you the actual elevation adjustment in inches at 100 yards. The added tech tip might show it better with pictures: TECH TIP: Burris Signature Rings — Calculating Actual Elevation Changes « Daily Bulletin