I have recently started preparation for doing mid to long range shooting, 1,200+ yards. The facility I started going to has a range that is maxed out at 1,250 yards, but has a huge field of known and unknown size and distance targets.

Well, a big part of the sport for me is to be able to hit an unknown sized target at an unknown distance, the very first shot. So, how the heck do you do that??? It's easy... figure out how far away the target is! LOL

I came across some well known formulas to do this. The reality is, unless you are shooting at a random rock out the the middle of the woods or flat lands... there is a really good possibility that there are going to be some things around that are "known size". We can use that to our advantage.

The first step is, know your target and what will be around your target. If you are going hunting for deer, coyote, boar, bear, etc... adult average sizes are all available.

Here are some examples:

Buck = 42" (106cm) shoulder height

Boar = 32" (81cm) shoulder height

Coyote = 18" (46cm) shoulder height

Most common rifle scopes measure angles via Milliradian (MRADs or Mils) or Minute of Angle (MOA). Before we get too far into this, There are a few misconceptions that need to be clarified. 1.) Milliradians is neither metric nor standard. It is its own unit of measure. However, Milliradians does work well with the metric system in the math world. 2.) Minute of Angle is neither metric nor standard. It is its own unit of measure. However, Minute of Angle does work well with the standard system in the math world.

Now, the fun part. Lets calculate some distances. As mentioned above, for people who think in metric, Mils is a great scope reticle to use for ranging targets. The formula is:

Target Height (cm) / Target Height (in mils) x 10 = Distance to Target in meters.

So, lets say you have an adult deer in your sights. We know the deer is about 106cm high. So, you look at the deer through your scope, placing the reticle over the deer in such a way that you can see how many mils the deer is, from his shoulder to the ground. In this example, we'll say the buck is 11 mils tall.

So, based on our new info, we can calculate the range to the target.

Target Height (106cm) / Target Height (11 mils) x 10 = Distance to Target in meters.

106 / 11 x 10 = 96.4 meters

Now, lets assume the buck measured 5 mils, then the math would be...

106 / 5 x 10 = 212 meters

If you have a 100 meter zero, you know what the range is and now you can either adjust your dial or holdover based on your ballistic performance.

Now that we have covered Mils, lets look at the ranging math for MOA. The formula and method are very similar to what we discussed about mils. The formula is:

Target Height (inches) / Target Height (MOA) x 100 = Distance to Target in Yards.

So, making the same assumptions, but using the standard system, we would see something like this.

Target Height (42 inches) / Target Height (11 MOA) x 100 = Distance to Target in Yards.

42 / 11 x 100 = 382 yards.

If you have a 100 yard zero, you know what the range is and now you can either adjust your dial or holdover based on your ballistic performance.

How does this help me at the range with a bunch of targets at unknown distance? Good question.

I bought a scope with an MRAD / Mils reticle, but I think in standard. So I need to do a bunch of extra math.

There are "waist up" human silhouettes for targets that are "to scale". That means that the targets are about 34 inches tall, a known size. When I look at the target in my reticle, it is 2 mils tall. So here is my math to adjust my point of aim or holdover.

34 in = 86 cm / 2 x 10 = 430 meters = 470 yards.

I have a 100 yard zero and we computed the distance in yards. Now I have a very important piece of knowledge to use my ballistic data to calculate my dial or holdover.

How sensitive the math is, all revolves around the size of the target, distance and your ballistic performance.

Here is an example. I am using a 6.5mm round that has decent ballistic characteristics. Generally speaking, my drop from a 100 yard zero would be 39.2" at 470 yards. Lets assume I guessed wrong and the target is really 30 inches. Well, that puts the target at 416 yards, not 470. That gives me a drop of 27.8", not 39.2". That is a difference of 11.4 inches over my point of aim.

On a 30" steel target, that is still a hit. However, the body of an adult buck is about 21". So, I missed the deer.

I hope this info is useful to you and you can have some fun at the range or improve your odds of landing those steaks you've been craving.