Still not shooting 400 meters. I would like to make your choice. At first sight aim shooting at this distance. This is a very important point.
If you are holding a post carefully, you will be holding a rifle while standing.
Why 400 meters?
On the flight bullets make it move along ballistic trajectory. Calculate the trajectory is not easy task. At the beginning of the flight, these forces do not strongly reject bullet. Therefore, they can simply be ignored.
They should be taken into account.
For example, take the 308 gauge.
Scenar Silver jacket, weight 9.10 bal. 0.4 speed of 800 m / s
- Earth’s pull at a distance of 150 meters.
- Side wind of 5 m / s at a distance of 180 meters.
- Height, if at 1 km. climbed the mountain, at a distance of 500 meters.
- Temperature change by 20 degrees 600 meters.
- Derivation 650 meters.
- Rotation of the earth at 900 meters.
- The rest of the forces will not affect.
It turns out that you can’t go back to 200 meters. For 400 meters we only consider distance and wind. Nothing more is required. Therefore, we choose a distance of up to 400 meters. It is necessary to study ballistics for long distances.
There is a clear picture of what is happening.
Departure angle or internal ballistics
There are things that are more important in measuring distances, winds and temperatures. They are called “Inner Ballistics.” In addition to the fact that “Inner Ballistics” automatic and semi-automatic weapons, it also makes certain adjustments in precision weapons. All these internal resonant oscillations can be reduced to one parameter, which is called “departure angle”.
Speaking differently, it will definitely deviate. AT any firearm.
To reduce this angle weapon, how the position of the arrow affects. Different people have the same rifle with same sight will fall into different places.
Therefore, the first rule: shoot only yourself. No one can target you rifle.
Departure angle will change from the arrow. Lying from the stop, with bipod, sitting, standing. At each position the arrow angle will be different. There was no loss of time for shooting. The greater the return, the stronger the dependence. There was a slight bore, 12-caliber bullet. Have semi-automatic dependence on bolt, even on one caliber.
How to deal with it?
Your only position. amendment table. I personally made for myself the table for shooting and bipods. As a rule, it is not allowed in practice.
The departure angle also depends on the type of cartridge. You charge other cartridge and he flew from a different angle. His deviation does not fit into external ballistics. Contradicts all calculations on any ballistic calculators. That is, you can’t calculate your trajectory, because it can not calculate internal ballistics and departure angle. Maybe this explains the general distrust of the shooters with experience.
Departure angle varies greatly vertically. And almost does not change horizontally. Which greatly facilitates the task. It is not necessary to touch it. But the vertical amendment will depend on the situation. It is necessary to match the number on the vertical drum. Changed the cartridge and flipped the amendment. Changed the position of the bipod, perekchelknuli drum.
It is necessary to note the number on the drum. In principle, if you sometimes shoot. Naturally, she will individual, everyone will have their own tablet.
Direct shot – shot from firearms, in which the trajectory of the projectile (bullet) does not rise above a given height of the target. Within the range of direct shot. This is a line-up. weapons, especially when shooting at moving targets.
This is not difficult to deal with. The trunk is located below sight. Therefore, the bullet after departure is below sight lines. The bullet begins to rise.
At some distance it crosses the axis of the trunk. This place is called first zero. Further flight above the axis of the trunk. It crosses the axis of the barrel. This distance is called second zero. We can assume that direct shot.
The effect of temperature on the flight of a bullet
Temperature changes sound speed and air density. It is considered in max. That is, in sound speeds. Resistance to the bullet. The second factor is air density. Cold air is denser hot air, which also affects the resistance.
Now consider how much it affects temperature on the flight of the bullet.
Scenar Silver jacket: bal. 0,400 beg. speed 800 m / s
if the temperature changes by 6 mm at a distance of 600 meters.
- 10 degree change
- a distance of 200 meters – 2 mm.
- a distance of 400 meters – 15 mm.
- a distance of 500 meters – 28 mm.
- distance of 600 meters – 58 mm.
- For our purposes, 28 millimeters at a distance of 500 meters means nothing.
if we compare the temperature of +20 and -20 Celsius. that is, a drop of 40 degrees.
- a distance of 200 meters – 5 mm.
- a distance of 400 meters – 63 mm.
- a distance of 500 meters – 124 mm.
- a distance of 600 meters – 287 mm.
Already sensitive. There is one more fact. In winter, you wear a warm jacket. she will change general ballistics and departure angle. This effect is even greater than the change in trajectory from temperature. Therefore, it is desirable to have two tablets: for winter and for summer. Sailing Thus, we will take into account and jacket, and the dependence on the temperature.
Air pressure changes its density. The denser of the air. bullet.
The pressure of 740 mm Hg. against 780 mm Hg
- at a distance of 200 meters 4 mm.
- at a distance of 400 meters 37 mm.
- at a distance of 500 meters 87 mm.
- at a distance of 600 meters 163 mm.
If you shoot at an average of 760 mm, it will give you less than 5 cm by 500 meters. In my opinion, air pressure can be completely ignored.
Now consider the mountain conditions. we will compare the difference between sea level and height
Height 200 meters
- a distance of 200 meters. 0 mm.
- distance of 400 meters. 15 mm.
- distance of 500 meters. 30 mm.
- distance of 600 meters. 55 mm.
Height of 1000 meters
- a distance of 200 meters. 5 mm.
- distance of 400 meters. 59 mm.
- distance of 500 meters. 130 mm.
- distance of 600 meters. 251 mm.
Height of 2000 meters
- a distance of 200 meters. 8 mm.
- distance of 400 meters. 105 mm.
- distance of 500 meters. 232 mm.
- distance of 600 meters. 553 mm.
If you live on plain, it is a bolt-on high in the mountains, for at least one height.
Derivation is manifested on rifle. The speed of about 160 thousand revolutions per minute. Gyroscopic effect keeps the bullet from tumbling. In the flight, according to the trajectory. When changing the axis of rotation gyroscopic effect depending on the direction of cutting. If you shoot in the wind?
Let’s see how much. Scenar Silver jacket, weight 9.10 bal. 0,400 beg. speed 800 cutting pitch 0.32 meters (twist 12.6)
- The distance is 200 meters 6 mm.
- The distance is 400 meters 30 mm.
- The distance is 500 meters 52 mm.
- The distance is 600 meters 87 mm.
As you can see – there is a deviation, but it is quite tolerable.
Bullet rejects not only gravity, but also the wind. will remove the bullet up or down. depends on wind direction and direction of rotation.
The wind of 5 m / s.
- The distance is 200 meters 19 mm.
- The distance is 400 meters 39 mm.
- The distance is 500 meters 49 mm.
- The distance is 600 meters 59 mm.
At a distance of 500 meters, the distance is not much affected. Therefore, you can simply forget about it.
In 1881, in Germany, Krupp (Krupp) If you know how to use it, then you can build a trajectory. In the 19th century, bullets of 10.67 mm were used. In subsequent centuries, the caliber began to decrease. The Krupp bullet is no longer suitable. If the bullet is tighter in shape but smaller in size, the resistance will be proportional. It turned out to be enough. So the ballistic coefficient appeared.
Further development small arms led to the creation of new bullets, with a different form. Krupp bullet.
Then they decided to create other graphics (drags). Some are included in the program.
- G1 – Model for the Krupp bullet.
- G7 – For bullets with a long conical tail (angle 7. 30?) And a tangential ogival part with a radius of 10 calibers
- GS – Model for a round bullet
- RA4 – For .22LR caliber
If known ballistic coefficient, that will be the trajectory. Unfortunately, it’s not the manufacturer. Or worse, points wrong. But almost always the manufacturer indicates the speed at a distance. This is already enough to determine ballistic coefficient.
The zeroing starts with a cold zero. Take laser cartridge, In the case of the line with the crosshair of the sight. If you don’t have laser cartridge, it can be without him. To do this, fasten the rifle still. A sighting machine. There are a lot of machine options. You can use any.
We direct the rifle to the target. look through the trunk at target center. then we turn the sheep. set the crosshair in center of target.
We assume that they made a cold adjustment.
Further the real adjustment adjustment. From the machine can not shoot. If you shoot from the machine, it will be adjusted. Rifle it will shoot exactly when it is on the machine. If you continue to use rifle From the position from which you will hunt.
To determine the center of accuracy. At the same time, the rifle. Then fasten the rifle in the machine. We look at the center of the target.
Then turn the drums, set it down gently. Loosen the screws on the scale to zero. Tighten the bolts. All rifle is adjusted.
True, this is your shot.
This is the most difficult moment in shooting decent distance. The wind is very hard to calculate. More precisely, it is hard to measure. If you couldn’t measure the wind distances, That calculation is done easily. If you are an anemometer, you can. The wind distances, one can only guess. The wind doesn’t blow at a constant speed, often with gusts, changing every second. Here you can only rely on experience and luck.
A little bit about the demolition of the wind bullets. It is a misconception. In fact, the situation is slightly different. This is a winding wavelength. It depends on the speed of the bullet. Nothing more. If you want to get quick calibers. For example 300 caliber.
Example: Scenar Silver jacket, weight 9.10 bal.kof. 0,400 crosswind 5 m / s
Calculation for open sight. therefore, instead of drum numbers, drop in centimeters. Deviation with side wind of 5 m / s.
- At 100 meters, the deviation is 2 cm.
- At 200 meters the deviation is 10 cm.
- At 400 meters, the deviation is 43 cm (it didn’t fit into the printout)
Long thought how to draw a deviation from the wind. For the SVD.
- 5 m / s is the average wind.
- 10 m / s is a strong wind. The resulting value must be multiplied by two.
Wind 10 m / s
- At 100 meters, the deviation is 4 cm.
- At 200 meters the deviation is 20 cm.
- At 400 meters the deviation is 86 cm
2.5 m / s is a weak wind, then divide by two
- At 100 meters, the deviation is 1 cm.
- At 200 meters, the deviation is 5 cm.
- At 400 meters the deviation is 22 cm
Aiming point mentally portable against the wind, at the specified distance. If the wind is purely lateral, then the place of aiming in the side. It has not moved. At all intermediate corners, we will be. Only experience will help here.
There are sights with drums, which are closed with lids. These sights are designed for long distances. With the help of these sights, you can only shoot at a distance direct shot. Depending on the situation the drum and have a direct shot to 200 meters. This is enough for all types of hunting.
Tactical the drums the value of the distance. We will shoot them up to 400 meters.
We need to know the distance. Use of range finders, or in any available way.
For a distance of 400 meters, it’s not necessary.
For shooting at 200 meters, nothing is needed. In addition to the initial shooting poses,
If you are a winding horse