Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

Incorrect determination of the range to the target is the most common cause of misses during long-range shooting. More common than a poor wind score, more common than pulling the trigger than misplacing an aiming point or making a lead. More common than incorrect vertical corrections. 

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

If you incorrectly determined the distance to the target, most likely you will miss. There are several reasons for this. The most serious of them is that the trajectory of the bullet, which is an arc, begins to decrease more and more at large distances, so even a small error has a big impact. Below we showed the trajectory of the bullet .308 Federal Match.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

Notice that at 100, 200, and 300 yards, she flies along a gentle path. Even if you made a big mistake in determining the range – say, you decided that the target was 300 yards away from you, while the actual range was 200 yards – at close range, you will probably hit your target, aiming at the center of the chest.

But, for example, you mistakenly decided that the target is 600 yards, but actually only 500 yards – well, now the difference in trajectory is about 3 feet. You see, at a farther distance, the bullet decreases in a steeper arc, and even minor errors become major.

Unfortunately, as the distance to the target increases, we also more often and more clearly make mistakes in determining it. But another serious problem associated with determining the distance to the target is that the errors are summed up and complicate all subsequent calculations of wind corrections, lead-times, and so on. And this can lead to misses even at close distances..

Look at the figures below, in which we consider the total effect of errors when shooting at a target that is only 400 yards away. Despite the fact that the sniper did each individual calculation correctly, with the exception of the initial determination of the distance to the target, he completely missed the relatively close target.

The cumulative effect of errors in determining the distance to the target.

Since a number of other factors when aiming require an increase in corrections as the distance increases, they are very sensitive to any error in determining the range to the target. Therefore, the initial errors in determining the range to the target become cumulative, and even a slight error can lead to a complete miss..

For our example, let’s assume that the target is indeed at a range of 400 yards, but our sniper mistakenly decided that the range is 300 yards. We will assume that he shoots with 168 .308 Match bullet and the rifle is shot at 300 yards. Notice how his errors accumulate:

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

Thus, we have shown in the illustration how just one fundamental error in determining the range to the target accumulates and leads to a complete miss.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

These corrections differ only due to differences in range measurement. This miss is caused by poor range definition. While a correctly applied amendment should lead to a defeat of the center of mass.

We are going to consider several different devices and methods for determining the distance to the target, but as you consider them, keep in mind that you should practice them while lying down. This way, you will learn to use them the way you actually act..

Determining the range to the target through the reticle of an optical sight or binoculars.

Any “duplex” reticle has its inherent ability to measure ranges. All that is needed is the exact dimensions of the grid. Consider the reticle “duplex” company Leupold, which exists in the sight 3,5-10x, when it is set to the maximum magnification.

The thinnest part of the aiming filaments is 10 MOA from edge to edge. This corresponds to 10 inches at 100 yards, then 20 inches at 200 yards, and so on. We showed how this mesh looks when applied to a person. Please note that we always leave the upper thick part of the aiming thread above the upper part of his head, not at his feet, since the probability that we will see the upper part of the target, and not its base, is much higher, especially at long ranges.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

When it is 600 yards from us, the target fills the entire thin part of the grid. But be careful: to be precise, you always determine the distance to the target with the help of your sight, set to the same magnification.

We can thank the FBI Special Agent Matthew Bowen Johnson for developing this method during his service at the FBI Quantico Fire Training Courses. He is a wonderful shooter and a true southerner gentleman. His method works with any duplex network. All you need is the exact dimensions of the grid.

Leupold further developed Johnson’s Special Agent method and introduced a range ring, located next to the zoom ring on its Vari-X III sights. All that the arrow needs to do is turn the zoom ring back and forth until the crosshairs of the reticle and the edges of the duplex cover a 16-inch segment, and then read the range value from the zoom ring.

This is not as accurate as measuring a range with a laser rangefinder, but more accurate than most eye methods. Some manufacturers of optical sights, including Schmidt Bender, put a vertical “step” range finder in the reticle to quickly determine ranges.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

Here, the shooter places a vertical scale on the human target to determine the range, enters the correction, and shoots. This is also not a very accurate method, but it is extremely fast and is intended only for relatively close distances, up to 400 meters.

The method of measuring the distance to the target using the thumb and eye methods.

I should also thank FBI Special Agent Johnson for teaching me how to determine the range to a target that probably dates back to the time of the long Kentucky rifle.

As shown in the illustration, fully extend one arm and raise your thumb so that the nail is immediately below your target and the target is on the very edge of the nail. Now imagine that your target turned to the left and took a certain number of normal steps to go through the entire width of your nail. This is the range to her in hundreds of yards..

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

If only one step is required, she is 50 yards from you. Two steps means she is 100 yards away, and so on. But only up to 200 yards maximum, because you probably won’t be able to accurately divide the width of your finger more precisely than one quarter.

Our next illustration shows a method that has long been used in the army. It is called the “soccer field” or “100-yard stretch” method. To use it, mentally divide the distance into 100-yard sections, clearly visualizing the length of the football field. Or imagine the first 100 yards. Then mentally add them again and again to full range.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

When the distance becomes more than 500 yards, or if any element of the earth’s surface is below your line of sight, the way the soccer field becomes less and less accurate. Usually, it is better to divide the entire distance in half, and then evaluate only the nearest half and double it. It is not surprising that this method is called the method of “half the distance”.

Using any method of determining distances – and especially eyeballing – compare your results with those that your teammate received, and take the average value. Usually, this average is more accurate than any of your individual estimates..

When using these eye methods, there is a danger that in some situations our eyes may deceive us. These general visual effects are shown in the illustration..

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

The goal seems closer when:

It is located behind the lowering terrain, most of which is hidden from your sight..
You watch down the hill.
You are looking along a straight line, such as a road or rail.
It is on a flat, uniform surface. Like snow or sand, especially in bright sunlight.

The goal seems further if:

It is small compared to the surrounding area..
She is taller than you.
The field of view is very narrow, such as when observing along a path.
You look through the lowering of the terrain, and it is completely visible to you.

Using a topographic map to determine the distance to the target.

When I tell cadets that one of the easiest and most accurate ways to determine range is to use a map, they usually say, “Why, I couldn’t even think about it.” This is so elementary and so obvious, but very often this is the last way the sniper thinks about using it. And he probably should be the first.

Obviously, the easiest approach is to map the location of your location and the location of your target and simply measure the distance. Although this does not always work. Because sometimes you are not sure about the location of your goal. In this situation, look around until you see some noticeable local object, which is probably located at the same distance, and measure this distance on your map.

A more accurate range estimate can be made by using GPS together with your card. Making sure there is a distinctive local item near the target. Set your exact GPS location. Map this location and the location of the target. Then measure the distance and you will recognize it.

Counting poles and power transmission poles for determining the distance to the target.

If you look carefully around your area of ​​activity, you may notice some artificial local objects that are set at the same distance from each other, and which you can use to determine your range. Most often there are poles from fences and poles of power lines or telephone lines. Similar items can be very helpful. But make sure that they are indeed placed at standard intervals..

Since power transmission towers are expensive to install, and most landowners do not like them, energy companies tend to place them as far apart as possible, as far as safety requirements permit. And usually this is a precisely defined distance. Although additional supports can be added for additional support on the river or on the hill, the distance should be relatively constant.

On the other hand, fence posts vary from landowner to landowner, and I would hesitate to trust too much at a consistent interval. Although, of course, it’s worth checking.

The effect of errors in determining the distance to the target.

Since the trajectory of the bullet at the beginning has a slight upward slope, and then decreases more and more as the bullet slows down, errors in determining long range to the target are forgiven much less than errors at short distances.

To help you evaluate this, we present data for a 168-grain .308 Match bullet to show how a small error of 10 yards when determining the distance to the target affects the position of the bullet at different ranges.

Methods for determining the range to the target, errors in determining the range, determining the range through the reticle, using the thumb and eye methods.

Now look how easy it is to think that the target is 750 yards when it is actually 800 yards. But this error of 50 yards (less than 10 percent) will cause the bullet to hit 32 inches lower, a significant miss. Keep this in mind when determining your target range..

Based on the book “The Perfect Sniper. Study Guide for Army and Police Snipers ».
Maj. John L. Plaster, USAR (Ret.)

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