offset risers and 60mm rule?

[Jordan1s]

Hello,

I was wondering, when using both offset and elevation, is the 60mm measured as A or B? The main reason why i ask this is because i am having trouble understanding the 60mm restriction. Ex: Say I were hypothetically using an unrealistic offset of 20mm, would I still be able to use 20mm of elevation as well and still be within the 60mm restriction?

thanks!

-Jordan

[jhmartin]

The rule is center of bore to center of the aperture - measurement A

However, in equipment checks that use overlays, they actually check B