Re: How to measure scope over bore
Diameter of the action, divided by two = A.
Diameter of the scope tube, divided by two = B.
Gap between scope & action = C.
A + B + C = distance between bore axis and scope axis, or "scope height over bore".
Using this method, we can get within a few thousandths, but that is more precise than we actually need.
If you look at some ballistics charts run with some variation in this number, you'll note that within 1/4" is close enough for most applications. Most folks can eyeball within 1/4" just holding a scale or rule against the side of the rifle.....