Do the markings on a sight tape stay exacty linear with all bows? Eg: if 20m and 30m is exactly 10mm apart, will 50m and 60m also be 10mm apart? I have to make my own sight tape, so I was wondering if this logic holds. I manually sighted in from 20 to 50, and mine seems to be spaced 7mm apart all the way to 50.