I was interested in this problem.
Buying some new mounts the sportsmatch say they fit 9.5 to 11.5 mm dovetails. As they only clamp on one side I checked my dovetail width. Hmm it was 11mm. So I think that means the scope will be 0.5mm out of line with barrell i.e. 0.5 to the left of the barrel or am I missing something?
If so then I must be setting the scope windage to aim right a little at say 20 yards [if this is my zero] - So therefore when I aim at 60 yards will I only be 1.5mm off to the right theoretically or am I off with my theory