TJH,

The calculation that you need is:

C/E = SR/R or C = SR*E/R

where "C" = change (in sight height, either up or down)
"E" = error (on target)
"SR" = sight radius
"R" = range

All number must be in the same dimension, as all inches or such. As stated, in your case (keeping the rear the same), your front would go down by this fraction.

How does the dovetail look? Is it clean and precise? If so, maybe the installer simply miscalculated the height or included the dovetail depth in his measurement by mistake. What I'm saying is that it might have been an "honest" mistake. If so, why not let him correct it? If I ever make (yeah, right... ) a misteak, I would much prefer that someone give me a chance to correct it than to go away with a bad feeling and possibly hurting my reputation. As hard as we try, we sometime rush or just have a bad moment or day.

David