I know that with iron sights and a sight radius of 36", movement of the rear sight gives a one MOA change for each .010" of sight movement. I know that isn't mathematically precise, but close enough.

So with a scoped rifle and sight base spacing of 6", would you get one MOA of change for each .001" of shim?

If I'm wrong, what would each .001" of shim produce in MOA?

Paul

You can do this for whatever spacing and shim with a scientific calculator.

Make sure the calculator is in degree mode.

MOA = arctan(shim amount / spacing) x 60

For example, .001 shim over 6" spacing gives us arctan(.001/60) = .00955 degrees. This times 60, for sixty minutes per degree, gives .573 minutes of angle.

Know why your called mathman now.

That made my head hurt.

There's another, perhaps simpler calculation. 6" goes into 100 yards 600 times, so a deflection of 0.001" over 6" should give rise to a deflection of 0.001 x 600 = 0.6" at 100 yards.

Mine too! And I was good at math in school (but that was a long time ago)