Speed,
The cant of a 20MOA base will have a negligable effect on the scope's height above bore. For a goof, change the scope height data in EXBAL by .1" and see how much it affects your drop at 600yds and you'll see for yourself...
Just measure the center of your scope's main tube to the center of your barrel. If you have horizontally split rings, measuring from the the split in the rings to the center of your barrel . A ruler works fine, or use your calipars /ubbthreads/images/graemlins/grinning-smiley-003.gif If it makes you feel better, you can measure in both the front and rear, then input the average...
