While shooting lines with a theodolite the other day I started wondering several things.
One thing I was thinking about was.. if stadia is simply 1 in 100 than what ratio is a mil-dot. I have used the "size of the target in yards x 1000 / mil reading" and "size of the target in inches / mil reading x 27.776" but never really thought about ratios.
I started playing with the numbers.... 1 mil is roughly 3.6" in 100 yrds or 3.6" in 300 feet or 1 inch in 83.333 feet or 1 inch in 1000 inches.
If I follow 1 inch in 83.333 feet I could also figure the following..." target in inches / mil reading x 83.333 / 3 = range in yards" it would also make sence that " size of the target / mil reading x 1000 / 36 = range in yards"
If one minute of angle is 1.04" in 100 yrds than it follows that 1 minute is also 1.04 in 300 feet or 1 in 3461.53 or 1 inch in 96.15 yards so it would also follow that the size of the target in inches / minutes x 96.15 = yards to target" or " size of target in inches / 1.04 / minutes x 100 = range in yrds"
This also gave me the idea to see what ratios my variable scope could equate to and if I could reliably use them to range. I decided to use my Millett lrs-1. This scope "mils" at 12.5 x and is 1/2 mil at 25 x. I divided 1 by 12.5 and came out with .08. To quick check I multiplied .08 by 25 and came up with 2. so it followed that if I divided the mil reading by (.08 x power setting ) and substituted that number for mil reading than I could range at power level. Than set up a tape measure at 100 yrds to check my theory. and IT WORKED!!
so it follows that "size of the target in inches /( mil reading / ( (1/mil power) x power))x83.333 / 3 = range to target in yards"