Rangefinding

Reforger Series

• Tips
• Range finding
• Common Measurements
• Medical
• Rifle Section
• LAV

Binoculars with mil ticks

• https://en.wikipedia.org/wiki/Milliradian#Units_for_target_size_and_range
• https://www.reddit.com/r/ArmaReforger/comments/1jfuen2/us_m22_binocular_range_finding/
• https://www.schaper.net/binoculars/steiner/m22/
• Range Estimation with ACOG and M22 Binocular

The field manual entry

• The ticks on the axis represent 5 milliradians

On the example UAZ-469, with a length of approximately 4 meters, one can
estimate its distance.

As it is 20 milliradians long we can make the calculation

(4 x 1000) \ 20 = 200. The vehicle then is 200 meters away.

Mils meaning

1 mil is 1 meter in width or height at 1000 meters.

If an object fills 10 mils in the binos, and is known to be 1 m high, the object
is 100 m away.

If an object fills 10 mils in the binos, and is known to be 10 meters wide, the
object is 1000 meters away.

6400 mils in a circle. (NATO)

18 mils in 1 degree.

Mils Math

Either way works out the same:

• Distance = (Target Size / Mil Reading) * 1000
• Distance = (Target Size in meters * 1000) / mils
• Distance = Target Size in milimeters / mils

A person is 1.8 m tall.

The tick marks in binoculars are 5 mil apart.

(1.8 * 1000) / 10 = 180 m

5 = 360

A BTR broadside is 8 meters long, or 8000 milimeters, thus if the BTR occupies 20 mils in the binos:

8000 / 20 = 400 m

Further math to round out the formula:

• size(mm) / mils = range(m)
• range * mils = size
• size / range = mils

A handy way to remember the range formula is:

milimeters over mils = meters

For object size reference see Common Measurements.

EOTECH range estimation

The EOTECH donut is a 60 MOA ring surrounding a 1 MOA center dot.

The donut provides several aiming points:

• Center dot: out to 300 m ish the center dot is usually accurate enough
• Bottom tick mark can be used to engage targets out to 600 m

We can then estimate range based on the ratio of target to donut

100 meters

A man-sized target will fill the entire 68 MOA circle from top to bottom.

Aim point center dot.

200 meters

The target will reach from the center dot to the bottom of the donut.

Aim point center dot.

300 meters

The target will cover approximately two-thirds of the distance from the
center dot to the bottom of the donut.

Aim point center dot.

400 meters

The target will fill about one-fourth of the distance from the center
dot to the bottom of the donut.

Aim point halfway point between center dot and bottom of donut.

500 + meters

The target is tiny.

Aim point is tick mark at bottom of donut.

M21 with ART II Scope

https://youtu.be/Gi_hY4oxCiY?si=cmLPoB9xLrC0G56B

Using the Centerline and bottom dot in the ART scope, zoom to target until the distance between centerline and bottom dot is about 1 meter, (half the height of a standing person for example). Now check the magnification in the lower right and multiply by 100 = Range to target.

Put another way:

Centerline on helmet, zoom in until lower dot on belt buckle (about the waist). That magnification * 100 is your range to target.

Elcan C79 optic

• https://en.wikipedia.org/wiki/C79_optical_sight
• https://army.ca/forums/resources/c-79-optical-sight-fact-sheet.10/download

The reticle of the C79 sight was designed to serve on the C9 Light Machine Gun, thus an appropriate pattern was chosen to aid the gunner in judging distance.

The reticle consists of a single vertical post with a sharp tip in the center.

The tip is flanked by horizontal stadia lines on either side of 10 mils each.

Under the right-hand stadia line, a second horizontal line is used for judging distances.

Ranging using horizontal lines

Ranging on man sized targets is done by fitting the target between the right side stadia lines.

Target	Range
Head	100 m
Upper body	300 m
Man	600 m

Ranging using 10 mil stadia lines

The 10 mil stadia lines can be used to estimate ranges on vehicles or other large objects of known sizes.

For example a BTR front that takes up half a stadia line (5 mils) would be:

3000 / 5 = 600 m

Another example looking at an MI-8 parked.

The rotor width is 21.3 meters.

In the C79 the rotor width is 4 stadia line sections which is 40 mils.

21300 / 40 = 532.5 meters