This will be a simple, straightforward article covering an important topic to achieve correct data for your shooting program.
What you’ll need
Pen and paper (unless you math well)
Calculator (in case you don’t)
Measuring device (caliper, rule, etc)
Measure the diameter of the air tank and eyepiece.
The center of the bottle will align with the centerline of the bore.
Divide the diameters of the air tank and eyepiece. Add the results together.
Measure the distance between the top of the air tank and the bottom of the eyepiece and record your numbers:
Add the distance between bottle and eyepiece to the radius’
The eyeball method indicated 3.5″ scope height. This is done by placing a rule at the centerline of the scope and reading at the centerline of the bore, which is centered inside the frame.