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Rice. rifled barrel device
Chamber - designed to accommodate the cartridge, corresponds to the shape and size of the sleeve.
Bullet entry - connects the chamber and the rifled part, serves to smoothly plunge the bullet into the rifling.
Threaded part- has rifling of a full profile and serves to give the pool a rotational motion.
The direction of the rifling can be right or left (right is accepted in domestic weapons). The length of the stroke (pitch) of the rifling provides the speed of the rotational movement of the bullet. The length of the rifled part is selected from the conditions for obtaining the required initial velocity of the bullet. The number of rifling depends on the caliber of the barrel and is selected from the pressure conditions of the bullet shell on the combat edge of the rifling.
For example, in stems small arms caliber 5.45 - 9 mm can have 4 or 6 grooves, in weapons of caliber 12.7-14.5 mm - 8 grooves, in 30-mm and 40-mm anti-personnel grenade launchers, as a rule - 12 grooves.
Ballistics
Ballistics- the science of the movement of projectiles.
Like any other science, ballistics has grown on the basis of human practical activity. A lot of experience was gained in throwing stones, spears, and darts. The main development was ballistics as a science with the advent of firearms, based on the achievements of other sciences - physics, chemistry, mathematics, aerodynamics.
Ballistics is divided into two parts - internal and external.
Internal ballistics- studies the phenomena occurring in the bore of a weapon during a shot, the movement of a projectile along the bore and the nature of the increase in the speed of the projectile both inside the bore and during the aftermath of gases.
Shot and its periods
Shot is called the ejection of a bullet from the bore of a weapon by the energy of gases formed during the combustion of a powder charge. An essential feature of the shot is that the main work of powder gases to push the projectile occurs in a variable volume.
The shot occurs in a short period of time (0.001-0.06 sec).
When fired from small arms, the following phenomena occur. From the impact of the striker on the primer of a live cartridge sent into the chamber, the percussion composition of the primer explodes and a flame forms, which through the seed holes in the bottom of the sleeve penetrates to the powder charge and ignites it. When a powder (combat) charge is burned, a large amount of highly heated gases are formed, which create high pressure in the barrel bore on the bottom of the bullet, the bottom and walls of the sleeve, as well as on the walls of the barrel and bolt, which is called forcing pressure ( Ro) necessary in order to move the bullet from its place and overcome the resistance of its shell to cutting into the rifling of the barrel.
The highest gas pressure ( Rmax) reaches when the bullet is 4-6 cm from the beginning of the rifled part of the barrel. By this time, the pressure of powder gases reaches 280-290 MPa. Speed ( V) as a result, the movement of the bullet increases.
The whole complex of processes occurring during a shot is divided by internal ballistics into a number of separate issues, and the very phenomenon of a shot divided into 4 periods:
Preliminary;
Period effects of gases.
The division of the phenomenon of a shot into periods is based on the possibility for each individual period to make mathematical calculations of the values of gas pressure and projectile velocity.
Rice. shot periods.
Preliminary period lasts from the beginning of the burning of the powder charge to the complete cutting of the shell of the bullet into the rifling of the barrel.
The first, or main, period lasts from the beginning of the movement of the bullet until the moment of complete combustion of the powder charge. During this period, the combustion of the powder charge occurs in a rapidly changing volume.
Second period lasts from the moment of complete combustion of the powder charge until the moment the bullet leaves the barrel. With the beginning of this period, the influx of powder gases stops, however, highly compressed and heated gases expand and, putting pressure on the bullet, increase its speed.
For some types of small arms, especially short-barreled ones (for example, the Makarov pistol), there is no second period, since the complete combustion of the powder charge does not actually occur by the time the bullet leaves the barrel.
third period, or period effects of gases, lasts from the moment the bullet leaves the bore until the moment the powder gases act on the bullet.
Hot powder gases flowing from the barrel behind the projectile, when they meet with air, cause a shock wave, which is the source of the sound of the shot. The mixing of hot gases (including carbon monoxide and hydrogen) with atmospheric oxygen causes a flash, observed as a shot flame.
The main work of the powder gases is spent, on the one hand, on giving the projectile translational and rotational motion, and on the other hand, on the recoil of the weapon.
The work expended on communicating translational and rotational motion to the projectile is approximately 20-35% of the total energy of the powder gases (this value is the efficiency of the weapon, 10-25% is spent on secondary work, and 40-50% of the energy is thrown out and lost after the projectile leaves the barrel.
The study of the phenomenon of a shot also makes it possible to draw conclusions of a purely applied nature on the justification of the rules for the operation, storage and inspection of weapons, a conclusion about the strength and survivability of the barrel.
Information from internal ballistics
Internal ballistics - this is a science that studies the processes that occur when a shot is fired, and especially when a bullet (grenade) moves along the bore.
Shot and its periods
Shotis called the ejection of a bullet from the bore of a weapon by the energy of gases formed during the combustion of a powder charge.
During the combustion of a powder charge, approximately 25-35% of the energy released is spent on communicating the progressive motion of the pool (the main work); 15-25% of energy - for minor work (cutting and overcoming the friction of a bullet when moving along the bore, heating the walls of the barrel, cartridge case and bullet, moving the moving parts of the weapon, gaseous and unburned parts of gunpowder); about 40% of the energy is not used and is lost after the bullet leaves the bore.
The shot occurs in a very short period of time (0.001-0.06 sec).
When fired, four consecutive periods are distinguished:
· preliminary;
· first (main);
· second;
· the third (the aftereffect period of gases).
Preliminary period lasts from the beginning of the burning of the powder charge to the complete cutting of the shell of the bullet into the rifling of the barrel. During this period, the gas pressure is created in the barrel bore, which is necessary in order to move the bullet from its place and overcome the resistance of its shell to cutting into the rifling of the barrel. This pressure is called forcing pressure; it reaches 250-500 kg / cm2, depending on the rifling device, the weight of the bullet and the hardness of its shell.
First or main period lasts from the beginning of the movement of the bullet until the moment of complete combustion of the powder charge. During this period, the combustion of the powder charge occurs in a rapidly changing volume. At the beginning of the period, when the speed of the bullet along the bore is still low, the amount of gases grows faster than the volume of the bullet space (the space between the bottom of the bullet and the bottom of the case), the gas pressure rises rapidly and reaches its highest value. This pressure is called maximum pressure. It is created in small arms when a bullet travels 4-6 cm of the path. Then, due to the rapid increase in the speed of the bullet, the volume of the bullet space increases faster than the influx of new gases, and the pressure begins to fall, by the end of the period it is equal to about 2/3 of the maximum pressure. The speed of the bullet is constantly increasing and by the end of the period reaches approximately 314 of the initial speed. The powder charge completely burns out shortly before the bullet leaves the bore.
Second periodlasts from the moment of complete combustion of the powder charge until the moment the bullet leaves the barrel. With the beginning of this period, the influx of powder gases stops, however, highly compressed and heated gases expand and, putting pressure on the bullet, increase its speed. The pressure drop in the second period occurs quite quickly and at the muzzle - muzzle pressure- is 300-900 kg / cm2 for various types of weapons. The speed of the bullet at the time of its departure from the bore (muzzle velocity) is somewhat less than the initial velocity.
Third period, or aftereffect period of gases , lasts from the moment the bullet leaves the bore until the moment the powder gases act on the bullet. During this period, the powder gases flowing out of the bore at a speed of 1200-2000 m/s continue to act on the bullet and impart additional speed to it. The bullet reaches its greatest (maximum) speed at the end of the third period at a distance of several tens of centimeters from the muzzle of the barrel. This period ends at the moment when the pressure of the powder gases at the bottom of the bullet is balanced by air resistance.
shot phenomenon
From the impact of the striker on the primer of a live cartridge sent into the chamber, the percussion composition of the primer explodes and a flame forms, which through the seed holes in the bottom of the sleeve penetrates to the powder charge and ignites it. When a powder charge is burned, a large amount of highly heated gases are formed, which create in the bore high pressure on the bottom of the bullet, the bottom and walls of the sleeve, as well as on the walls of the barrel and the bolt. As a result of the pressure of gases on the bottom of the bullet, it moves from its place and crashes into the rifling; rotating along them, it moves along the bore with a continuously increasing speed and is thrown outward in the direction of the axis of the bore. The pressure of gases on the bottom of the sleeve causes the weapon to move backward. From the pressure of gases on the walls of the sleeve and the barrel, they are stretched (elastic deformation), and the sleeve, tightly pressed against the chamber, prevents the breakthrough of powder gases towards the bolt. At the same time, when fired, an oscillatory movement (vibration) of the barrel occurs and it heats up. Hot gases and particles of unburned powder, flowing from the bore after the bullet, when they meet with air, generate a flame and a shock wave, the latter is the source of sound when fired.
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When fired from an automatic weapon, the device of which is based on the principle of using the energy of powder gases vented through a hole in the barrel wall (Kalashnikov assault rifles and machine guns), some of the powder gases, in addition, after the bullet passes through the gas outlet, rushes through it into the gas chamber, strikes piston and throws the piston with the bolt carrier back.
Until the bolt carrier has traveled a certain distance to allow the bullet to exit the bore, the bolt continues to lock the bore. After the bullet leaves the barrel, it is unlocked; the bolt frame and bolt, moving backward, compress the return spring; the shutter at the same time removes the sleeve from the chamber. When moving forward under the action of a compressed spring, the bolt sends the next cartridge into the chamber and again locks the bore.
Sometimes, after the striker hits the primer, the shot will not follow, or it will happen with some delay. In the first case, there is a misfire, and in the second, a protracted shot. The cause of a misfire is most often dampness of the percussion composition of the primer or powder charge, as well as a weak impact of the striker on the primer. A protracted shot is a consequence of the slow development of the process of ignition or ignition of a powder charge.
muzzle velocity
initial speed called the speed of the bullet at the muzzle of the barrel. For the initial speed, the conditional speed is taken, which is slightly more than the muzzle and less than the maximum. It is determined empirically with subsequent calculations. The value of the initial velocity of the bullet is indicated in the firing tables and in the combat characteristics of the weapon.
The initial speed is one of the most important characteristics of the combat properties of weapons. With an increase in the initial speed, the range of the bullet, the range of a direct shot, the lethal and penetrating effect of the bullet increases, and the influence of external conditions on its flight also decreases.
The value of the muzzle velocity depends on the length of the barrel; bullet weight; weight, temperature and humidity of the powder charge, the shape and size of the powder grains and loading density.
The longer the barrel, the longer the powder gases act on the bullet and the greater the initial velocity. With a constant barrel length and a constant weight of the powder charge, the initial velocity is greater, the lower the weight of the bullet.
A change in the weight of the powder charge leads to a change in the amount of powder gases, and, consequently, to a change in the maximum pressure in the bore and the initial velocity of the bullet. The greater the weight of the powder charge, the greater the maximum pressure and muzzle velocity of the bullet.
The length of the barrel and the weight of the powder charge increase when designing weapons to the most rational sizes.
With an increase in the temperature of the powder charge, the burning rate of the powder increases, and therefore the maximum pressure and initial speed increase. As the charge temperature decreases, the initial speed decreases. An increase (decrease) in initial velocity causes an increase (decrease) in the range of the bullet. In this regard, it is necessary to take into account range corrections for air and charge temperature (charge temperature is approximately equal to air temperature).
With an increase in the humidity of the powder charge, its burning rate and the initial speed of the bullet decrease.
The shape and size of the powder have a significant impact on the burning rate of the powder charge, and, consequently, on the muzzle velocity of the bullet. They are selected accordingly when designing weapons.
Loading density is the ratio of the weight of the charge to the volume of the sleeve with the inserted pool (charge combustion chambers). With a deep landing, the bullet significantly increases the density of loading, which can lead to a sharp jump in pressure when fired and, as a result, to a rupture of the barrel, therefore, such cartridges cannot be used for shooting. With a decrease (increase) in the loading density, the initial velocity of the bullet, the recoil of the weapon and the angle of departure increase (decrease).
Weapon recoil
The movement of the weapon backwards while firing is called recoil. The pressure of powder gases in the bore acts in all directions with the same force. The gas pressure on the bottom of the bullet makes it move forward, and the pressure on the bottom of the cartridge case is transmitted to the bolt and causes the weapon to move backward. When recoil, a pair of forces is formed, under the influence of which the muzzle of the weapon deviates upward. The recoil of small arms is felt in the form of a push to the shoulder, arm or into the ground. The recoil action of a weapon is characterized by the amount of speed and energy that it has when moving backward. The recoil speed of the weapon is about as many times less than the initial speed of the bullet, how many times the bullet is lighter than the weapon. The recoil energy of a Kalashnikov assault rifle is small and is perceived by the shooter painlessly, while that of a small-caliber rifle is almost not noticeable. To reduce the effect of recoil on the results of shooting, it is necessary to strictly follow the shooting techniques.
Test
Internal ballistics is a science:
engaged in the study of the laws of movement of weapons during firing.engaged in the study of the laws of motion of a bullet (grenade) in flight.
engaged in the study of the laws of recoil of weapons during firing.
engaged in the study of the laws of motion of a bullet (grenade) in the channel of the barrel of a weapon and the processes accompanying the movement.
Shot it:
complex thermodynamic process of very fast, almost instantaneous conversion of the chemical energy of gunpowder into heat, and then into kinetic energy powder gases propelling the bullet.complex process that sets the bullet in motion.
the process of rapid ignition of gunpowder.
the process of throwing a bullet from the bore.
When it comes to ammo, I consider myself nothing more than an amateur - I do a bit of ammo reloading, play SolidWorks, and read dusty tomes full of the hard work of people who have collected detailed information about ammo. I honestly crammed but not a true expert. But when I started writing, I found that very few people I meet know as much about cartridges as I do.
By the way, this situation is perfectly illustrated by comparing the number of participants in the IAA forum (about 3200 people at the time of writing), with the AR15.com forum, where the number of registered members is approaching half a million. And don't forget that IAA forum the largest English-language forum for collectors/ammunition enthusiasts- at least to my knowledge, and AR15.com is just one of the many large gun forums on the net.
In any case, being a part of the gun world both as a shooter and as an author, I have heard a lot of myths about ammunition and ballistics, some of them are pretty obvious to most people, but others are repeated much more often than they should be. What is behind some of these myths and what is the truth?
1. More is better
I put this statement first because it is the most widely used. And this myth will never die, as it is clear enough. If you have it handy, then take and compare the cartridge of caliber .45 ACP with 9 mm, or .308 Winchester with .223; any two cartridges that differ greatly in size and weight will do. This is true obviously, which makes the explanation somewhat more difficult, that a large cartridge is the best cartridge, since it does much more damage. There's a serious .45 ACP bullet in your hand, it's all three-quarters of an ounce (21.2 grams), and it even feels a lot more solid and powerful compared to a 9mm or .32 or any other smaller caliber bullet.
I won't spend much time making assumptions "why"? Maybe it all comes from our ancestors picking up stones in the river to hunt birds, but I think that such a reaction does not allow this myth to disappear.
Cartridges .308 Win RWS & LAPUA, as well as their ballistics.
But regardless of the cause, the external ballistics of different bullets is a complex subject, and often the results differ from the assumptions that can be made based only on the sizes of different bullets. High-velocity rifle bullets that devastate on impact, such as can inflict much more severe wounds than large-caliber bullets of larger weight and size, especially if the target is not protected. Explosive hollow-jacketed bullets, even in small calibers like .32, can shatter and cause more damage than a .45-caliber jacketed bullet. Even the shape of the bullet can affect the nature of the damage, so a flat, angular bullet will cut and tear tissue better than a larger caliber bullet with a rounded nose.
None of this says a larger caliber never is not more efficient, or that everything is the same and to a certain extent, modern porosity or expansion bullets do not differ in efficiency, the truth is that external ballistics bullets are much deeper and more complex, and often the actual results of different bullets are contrary to expectations.
2. Longer barrel = proportionally higher speed
This is one of the myths in which the catch is intuitively felt. If we double the length of the barrel, we double the speed, So? Most likely, for my readers it is obvious, it is not so, but there are still many people who hold this false claim (even the designer Loren C. Cook (Loren C. Cook) repeated this myth, advertising his submachine gun). This is an obvious assumption based on the information that longer rifle barrels (often) provide increased bullet velocity, but it is incorrect.
The relationship between barrel length and bullet speed is actually very differentiated, but its essence is this: When the powder in the cartridge ignites, gases are formed that expand and put pressure on the bottom of the bullet. When the bullet is clamped in the case, when the powder burns, the pressure rises, and this pressure pushes the bullet out of the case, and then pushes it along the bore, losing its energy, in addition, the pressure decreases due to a significant and constant increase in the volume in which the gas is located . This means that the energy of the propellant gases decreases with every inch of barrel length, and its maximum value is reached just in weapons with a short barrel. For example, increasing the length of a rifle barrel from 10 to 13 inches can mean an increase in bullet speed by hundreds of feet per second, while increasing the length from 21 to 24 inches can mean an increase in speed of only a couple of tens of feet per second. You often hear that the change in pressure and force on the bottom of a bullet is called "pressure curve".
In turn, this curve and its relationship with the length of the barrel is different for different charges. AT magnum cartridges rifle calibers use very slow burning explosive, which provides a significant change in the speed of the bullet even when using a long barrel. Pistol cartridges, on the other hand, use fast-burning propellants, which means that after a few inches, the increase in bullet speed due to the use of a longer barrel becomes negligible. In fact, shooting pistol cartridge from a long rifle barrel, you will get even slightly slower muzzle velocity compared to a short barrel, as the friction between the bullet and the bore will slow the bullet down more than the extra pressure will speed it up.
3. Caliber matters, bullet type doesn't.
This strange arrogant opinion pops up very often in conversations, especially in the form of the phrase: “Caliber X is not enough. You need a Y-gauge”, while the mentioned calibers differ little from each other. It is possible that someone chooses a caliber that is completely inappropriate for the task at hand, but most often such discussions revolve around cartridges that are more or less suitable for the task, with the right choice of bullet type.
And now such a discussion becomes more substantive than just a myth: in almost all such disputes, one should pay more attention to the choice of the type of bullet, and not to the caliber and power of the charge. After all, between the .45 ACP jacketed bullet and the .45 ACP HST expansive cavity bullet, the difference in efficiency is much greater than between the 9mm HST and the .45 ACP HST. Choosing one caliber or another probably won't make a huge difference in hitting results, but choosing the type of bullet definitely makes a difference!
Excerpts from an hour and a half seminar "Ballistics" by Sergei Yudin within the framework of the project "National Shooting Association".
4. Momentum = Stopping power
Momentum is mass multiplied by speed, a very easy-to-understand physical quantity. A large man running into you on the street will push you away more than a petite girl if they are moving at the same speed. More splashes from a large stone. This simple value is easy to calculate and understand. The larger something and the faster it moves, the more momentum it has.
That's why it was natural to use momentum as a rough estimate of the bullet's stopping power. This approach has spread throughout the gun community, from reviews that give no information other than that the larger the bullet, the louder the ringing sound of hitting a steel target, to Taylor Knock-Out Index, in which momentum is related to bullet diameter in an attempt to calculate stopping power over big game. However, although momentum is important ballistic performance, it is not directly related to the effectiveness of the bullet on impact, or "stopping power".
Momentum is a conserved quantity, which means that since the bullet moves forward under the action of expanding gases, the weapon, when fired by this bullet, will move backward with the same momentum as the total momentum of the bullet and powder gases. Which means that the momentum of a bullet fired from the shoulder or from the hands is not sufficient to cause even significant damage to a person, not to mention the murder. The momentum of the bullet, at the moment it hits the target, does nothing but possibly bruise the tissues and give a very small push. The lethality of a shot, in turn, is determined by the speed at which the bullet travels and the size of the channel that the bullet creates inside the target.
This article is deliberately written in an attention-grabbing and very general manner, as I plan to address these issues in more detail, at various levels of complexity, and I want to know how readers will be interested in such a topic. If you want me to talk more about ammunition and ballistics, tell me about it in the comments.
Interesting bullet ballistics from the National Geographic channel.
To successfully master the technique of shooting from any small arms, it is necessary to master the knowledge of the laws of ballistics and a number of basic concepts related to it. Not a single sniper could and does not do without this, and without studying this discipline, a sniping training course is of little use.
Ballistics is the science of the movement of bullets and projectiles fired from small arms when fired. Ballistics is subdivided into external and internal.
Internal ballistics
Internal ballistics studies the processes occurring in the bore of a weapon during a shot, the movement of a bullet along the bore and the aero- and thermodynamic dependences accompanying this phenomenon both in the bore and outside it until the end of the aftereffect of powder gases.
In addition, internal ballistics studies the issues of the most rational use the energy of the powder charge during the shot so that the bullet of a given caliber and weight is given the optimal initial speed while respecting the strength of the weapon barrel: this provides initial data for both external ballistics and weapon design.
Shot
Shot- this is the ejection of a bullet from the bore of a weapon under the influence of the energy of gases formed during the combustion of the powder charge of the cartridge.
Shot dynamics. When the striker hits the primer of a live cartridge sent into the chamber, the percussion composition of the primer explodes, and a flame is formed, which is transmitted through the seed holes in the bottom of the sleeve to the powder charge and ignites it. With the simultaneous combustion of a combat (powder) charge, a large amount of heated powder gases are formed, which create high pressure on the bottom of the bullet, the bottom and walls of the sleeve, as well as on the walls of the bore and the bolt.
Under strong pressure of powder gases on the bottom of the bullet, it is separated from the sleeve and cuts into the channels (rifling) of the weapon barrel and, rotating along them at a constantly increasing speed, is thrown outward in the direction of the axis of the barrel bore.
In turn, the pressure of gases on the bottom of the sleeve causes the movement of the weapon (the barrel of the weapon) back: this phenomenon is called bestowal. The larger the caliber of the weapon and, accordingly, the ammunition (cartridge) for it, the greater the recoil force (see below).
When fired from an automatic weapon, the principle of operation of which is based on the use of powder gases energy removed through a hole in the barrel wall, such as in SVD, part of the powder gases after passing into gas chamber strikes the piston and throws the pusher with the shutter back.
The shot occurs in an ultra-short period of time: from 0.001 to 0.06 seconds and is divided into four consecutive periods:
- preliminary
- first (main)
- second
- third (aftereffect period of powder gases)
Pre-shot period. It lasts from the moment the powder charge of the cartridge ignites until the moment the bullet completely cuts into the rifling of the barrel bore. During this period, sufficient gas pressure is created in the bore to move the bullet from its place and overcome the resistance of its shell to cutting into the rifling of the bore. This type of pressure is called boost pressure, which reaches a value of 250 - 600 kg / cm², depending on the weight of the bullet, the hardness of its shell, caliber, barrel type, number and type of rifling.
First (main) shot period. It lasts from the moment the bullet begins to move along the bore of the weapon until the moment of complete combustion of the powder charge of the cartridge. During this period, the burning of the powder charge occurs in rapidly changing volumes: at the beginning of the period, when the speed of the bullet along the bore is still relatively low, the amount of gases grows faster than the volume of the bullet space (the space between the bottom of the bullet and the bottom of the cartridge case), the gas pressure rapidly rises and reaches its maximum value - 2900 kg / cm² for a 7.62 mm rifle cartridge: this pressure is called maximum pressure. It is created in small arms when a bullet travels 4 - 6 cm of the path.
Then, due to a very rapid increase in the speed of the bullet, the volume of the bullet space increases faster than the influx of new gases, as a result of which the pressure begins to fall: by the end of the period it is equal to approximately 2/3 of the maximum pressure. The speed of the bullet is constantly increasing and by the end of the period reaches approximately 3/4 of the initial speed. The powder charge completely burns out shortly before the bullet leaves the bore.
Second shot period. It lasts from the moment of complete combustion of the powder charge until the moment the bullet leaves the barrel. With the beginning of this period, the influx of powder gases stops, but highly heated, compressed gases expand and, putting pressure on the bullet, significantly increase its speed. The pressure drop in the second period occurs quite quickly and the muzzle pressure at the muzzle of the weapon barrel is 300 - 1000 kg / cm² for various types of weapons. muzzle velocity, that is, the speed of the bullet at the time of its departure from the bore is slightly less than the initial speed.
The third period of the shot (the period of aftereffect of powder gases). It lasts from the moment the bullet leaves the bore of the weapon until the moment the action of the powder gases on the bullet ceases. During this period, powder gases flowing out of the bore at a speed of 1200-2000 m/s continue to act on the bullet and impart additional speed to it. Max speed the bullet reaches at the end of the third period at a distance of several tens of centimeters from the muzzle of the weapon barrel. This period ends at the moment when the pressure of the powder gases at the bottom of the bullet is fully balanced by the air resistance.
starting speed bullets
muzzle velocity- this is the speed of the bullet at the muzzle of the barrel of the weapon. For the value of the initial speed of the bullet, the conditional speed is taken, which is less than the maximum, but more than the muzzle, which is determined empirically and by the corresponding calculations.
This parameter is one of the most important characteristics of the combat properties of weapons. The value of the initial velocity of the bullet is indicated in the firing tables and in the combat characteristics of the weapon. With an increase in the initial speed, the range of the bullet, the range of a direct shot, the lethal and penetrating effect of the bullet increases, and the influence of external conditions on its flight also decreases. The muzzle velocity of a bullet depends on:
- bullet weight
- barrel length
- temperature, weight and humidity of the powder charge
- sizes and shapes of powder grains
- loading density
Bullet weight. The smaller it is, the greater its initial speed.
Barrel length. The larger it is, the longer the period of time the powder gases act on the bullet, respectively, the greater its initial speed.
Powder charge temperature. With a decrease in temperature, the initial velocity of the bullet decreases, with an increase, it increases due to an increase in the burning speed of the gunpowder and the pressure value. Under normal weather conditions, the temperature of the powder charge is approximately equal to the air temperature.
Powder charge weight. The greater the weight of the powder charge of the cartridge, the greater the amount of powder gases acting on the bullet, the greater the pressure in the bore and, accordingly, the speed of the bullet.
Powder charge moisture content. With its increase, the burning rate of gunpowder decreases, respectively, the speed of the bullet decreases.
The size and shape of the grains of gunpowder. Gunpowder grains of different sizes and shapes have different burning rates, and this has a significant impact on the muzzle velocity of the bullet. The best option is selected at the stage of weapon development and during its subsequent tests.
Loading density. This is the ratio of the weight of the powder charge to the volume of the cartridge case with the bullet inserted: this space is called charge combustion chamber. If the bullet is too deep into the cartridge case, the loading density increases significantly: when fired, this can lead to a rupture of the weapon barrel due to a sharp pressure surge inside it, therefore such cartridges cannot be used for shooting. The greater the loading density, the lower the muzzle velocity, the lower the loading density, the greater the muzzle velocity.
recoil
recoil- This is the movement of the weapon back at the time of the shot. It is felt as a push in the shoulder, arm, ground, or a combination of these sensations. The recoil action of the weapon is about as many times less than the initial velocity of the bullet, how many times the bullet is lighter than the weapon. The recoil energy of hand-held small arms usually does not exceed 2 kg / m and is perceived by the shooter painlessly.
The recoil force and the recoil resistance force (butt stop) are not located on the same straight line: they are directed in opposite directions and form a pair of forces, under the influence of which the muzzle of the weapon barrel deviates upward. The magnitude of the deviation of the muzzle of the barrel of a given weapon is the greater, the greater the shoulder of this pair of forces. In addition, when fired, the barrel of the weapon vibrates, that is, it makes oscillatory movements. As a result of vibration, the muzzle of the barrel at the moment the bullet takes off can also deviate from its original position in any direction (up, down, left, right).
It should always be remembered that the value of this deviation increases if the firing stop is used incorrectly, the weapon is contaminated, or non-standard cartridges are used.
The combination of the influence of barrel vibration, weapon recoil and other causes leads to the formation of an angle between the direction of the axis of the bore before the shot and its direction at the moment the bullet leaves the bore: this angle is called departure angle.
Departure angle it is considered positive if the axis of the bore at the time of the bullet's departure is higher than its position before the shot, negative - when it is lower. The influence of the departure angle on shooting is eliminated when it is brought to normal combat. But in case of violation of the rules for caring for a weapon and its conservation, the rules for applying a weapon, using an emphasis, the value of the angle of departure and the battle of the weapon change. In order to reduce harmful influence recoil on the results of firing, recoil compensators are used, located on the muzzle of the weapon barrel or removable, attached to it.
External ballistics
External ballistics studies the processes and phenomena accompanying the movement of a bullet that occur after the effect of powder gases on it stops. The main task of this sub-discipline is to study the patterns of bullet flight and the study of the properties of the trajectory of its flight.
Also, this discipline provides data for developing shooting rules, compiling shooting tables and calculating weapon sight scales. Conclusions from external ballistics have long been widely used in combat when choosing a sight and aiming point depending on the firing range, wind speed and direction, air temperature and other firing conditions.
This is the curved line described by the bullet's center of gravity during flight.
Bullet flight path, bullet flight in space
When flying in space, two forces act on a bullet: gravity and air resistance force.
The force of gravity causes the bullet to gradually descend horizontally towards the plane of the earth, and the force of air resistance permanently (continuously) slows down the flight of the bullet and tends to overturn it: as a result, the speed of the bullet gradually decreases, and its trajectory is an unevenly curved curved line in shape.
Air resistance to the flight of a bullet is caused by the fact that air is an elastic medium and therefore some part of the bullet's energy is expended on movement in this medium.
Force of air resistance caused by three main factors:
- air friction
- swirls
- ballistic wave
Shape, properties and types of toolpath
Trajectory shape depends on the elevation angle. As the elevation angle increases, the trajectory height and the full horizontal range of the bullet increase, but this happens up to a certain limit, after which the trajectory height continues to increase, and the total horizontal range begins to decrease.
The angle of elevation at which the full horizontal range of the bullet is greatest is called farthest angle. The value of the angle of greatest range for bullets of various types of weapons is about 35 °.
Hinged trajectory is the trajectory obtained at elevation angles greater than the angle of greatest range.
Flat trajectory- trajectory obtained at elevation angles smaller than the angle of greatest range.
Conjugate trajectory- a trajectory having the same horizontal range at different elevation angles.
When firing from weapons of the same model (with the same initial bullet speeds), you can get two flight paths with the same horizontal range: mounted and flat.
When shooting from small arms, only flat trajectories. The flatter the trajectory, the greater the distance the target can be hit with one sight setting, and the less impact on the shooting results is the error in determining the sight setting: this is the practical significance of the trajectory.
The flatness of the trajectory is characterized by its greatest excess over the aiming line. At a given range, the trajectory is all the more flat, the less it rises above the aiming line. In addition, the flatness of the trajectory can be judged by angle of incidence: the trajectory is more flat, the smaller the angle of incidence.
The flatness of the trajectory affects the value of the range of a direct shot, struck, covered and dead space.
Departure point- the center of the muzzle of the barrel of the weapon. The departure point is the start of the trajectory.
Weapon horizon is the horizontal plane passing through the departure point.
elevation line- a straight line that is a continuation of the axis of the bore of the aimed weapon.
Shooting plane- a vertical plane passing through the line of elevation.
Elevation angle- the angle enclosed between the line of elevation and the horizon of the weapon. If this angle is negative, then it is called angle of declination (descent).
Throw line- a straight line, which is a continuation of the axis of the bore at the time of the bullet's departure.
Throwing angle
Departure angle- the angle enclosed between the line of elevation and the line of throwing.
drop point- the point of intersection of the trajectory with the horizon of the weapon.
Angle of incidence- the angle enclosed between the tangent to the trajectory at the point of impact and the horizon of the weapon.
Total horizontal range- the distance from the point of departure to the point of fall.
Final speed b is the speed of the bullet at the point of impact.
Total flight time- the time of movement of the bullet from the point of departure to the point of impact.
Top of the path - highest point trajectories over the horizon of the weapon.
Trajectory height- the shortest distance from the top of the trajectory to the horizon of the weapon.
Ascending branch of the trajectory- part of the trajectory from the departure point to the top.
Descending branch of the trajectory- part of the trajectory from the top to the point of fall.
Aiming point (sighting point)- the point on the target (outside it) at which the weapon is aimed.
line of sight- a straight line passing from the shooter's eye through the middle of the sight slot at a level with its edges and the top of the front sight to the aiming point.
aiming angle- the angle enclosed between the line of elevation and the line of sight.
Target elevation angle- the angle enclosed between the aiming line and the horizon of the weapon. This angle is considered positive (+) when the target is higher and negative (-) when the target is below the weapon's horizon.
Sighting range- distance from the departure point to the intersection of the trajectory with the line of sight. The excess of the trajectory over the line of sight is the shortest distance from any point of the trajectory to the line of sight.
target line- a straight line connecting the departure point with the target.
Slant Range- distance from the departure point to the target along the target line.
meeting point- point of intersection of the trajectory with the surface of the target (ground, obstacles).
Meeting angle- the angle enclosed between the tangent to the trajectory and the tangent to the target surface (ground, obstacles) at the meeting point. The smaller of adjacent corners, measured from 0 to 90°.
Direct shot, covered area, hit area, dead space
This is a shot in which the trajectory does not rise above the line of sight above the target for its entire length.
Direct shot range depends on two factors: the height of the target and the flatness of the trajectory. The higher the target and the flatter the trajectory, the greater the range of a direct shot and the greater the extent of the terrain, the target can be hit with one sight setting.
Also, the range of a direct shot can be determined from shooting tables by comparing the height of the target with the values of the greatest excess of the trajectory above the aiming line or with the height of the trajectory.
Within the range of a direct shot, in tense moments of the battle, shooting can be carried out without rearranging the sight values, while the aiming point in height, as a rule, is selected at the lower edge of the target.
Practical use
The installation height of optical sights above the bore of the weapon is on average 7 cm. At a distance of 200 meters and the sight "2", the greatest excesses of the trajectory, 5 cm at a distance of 100 meters and 4 cm - at 150 meters, practically coincide with line of sight - optical axis of the optical sight. Line of sight height at the middle of the distance of 200 meters is 3.5 cm. There is a practical coincidence of the trajectory of the bullet and the line of sight. A difference of 1.5 cm can be neglected. At a distance of 150 meters, the height of the trajectory is 4 cm, and the height of the optical axis of the sight above the horizon of the weapon is 17-18 mm; the difference in height is 3 cm, which also does not play a practical role.
At a distance of 80 meters from the shooter bullet trajectory height will be 3 cm, and aiming line height- 5 cm, the same difference of 2 cm is not decisive. The bullet will fall only 2 cm below the aiming point.
The vertical spread of bullets of 2 cm is so small that it is of no fundamental importance. Therefore, when shooting with division "2" of the optical sight, starting from 80 meters of distance and up to 200 meters, aim at the bridge of the nose of the enemy - you will get there and get ± 2/3 cm higher lower throughout this distance.
At a distance of 200 meters, the bullet will hit exactly the aiming point. And even further, at a distance of up to 250 meters, aim with the same sight "2" at the enemy's "top", at the upper cut of the cap - the bullet drops sharply after 200 meters of distance. At 250 meters, aiming in this way, you will fall 11 cm lower - in the forehead or bridge of the nose.
The above method of firing can be useful in street battles, when relatively open distances in the city are approximately 150-250 meters.
Affected space
Affected space is the distance on the ground during which the descending branch of the trajectory does not exceed the height of the target.
When firing at targets located at a distance greater than the range of a direct shot, the trajectory near its top rises above the target and the target in some area will not be hit with the same sight setting. However, there will be such a space (distance) near the target in which the trajectory does not rise above the target and the target will be hit by it.
Depth of affected space depends on:
- target height (the higher the height, the greater the value)
- flatness of the trajectory (the flatter the trajectory, the greater the value)
- the angle of inclination of the terrain (on the front slope it decreases, on the reverse slope it increases)
Depth of affected area can be determined from the tables of the excess of the trajectory above the aiming line by comparing the excess of the descending branch of the trajectory by the corresponding firing range with the height of the target, and if the target height is less than 1/3 of the trajectory height, then in the form of a thousandth.
To increase the depth of the affected space on sloping terrain the firing position must be chosen so that the terrain in the enemy's disposition coincides, if possible, with the aiming line.
Covered, affected and dead space
covered space- this is the space behind the shelter that is not penetrated by a bullet, from its crest to the meeting point.
The greater the height of the shelter and the flatter the trajectory, the greater the covered space. Depth of covered area can be determined from the tables of the excess of the trajectory above the aiming line: by selection, an excess is found that corresponds to the height of the shelter and the distance to it. After finding the excess, the corresponding setting of the sight and the firing range are determined.
The difference between a certain range of fire and the range to cover is the depth of the covered space.
Dead space- this is the part of the covered space in which the target cannot be hit with a given trajectory.
The greater the height of the shelter, the lower the height of the target and the flatter the trajectory - the greater the dead space.
Pimaginable space- this is the part of the covered area in which the target can be hit. The depth of the dead space is equal to the difference between the covered and affected space.
Knowing the size of the affected space, covered space, dead space allows you to correctly use shelters to protect against enemy fire, as well as take measures to reduce dead spaces by right choice firing positions and firing at targets with weapons with a more trajectory.
This is a rather complicated process. Due to the simultaneous impact on the bullet of rotational motion, which gives it a stable position in flight and air resistance, which tends to tip the bullet head back, the axis of the bullet deviates from the direction of flight in the direction of rotation.
As a result of this, the bullet encounters more air resistance on one of its sides, and therefore deviates from the firing plane more and more in the direction of rotation. Such a deviation of a rotating bullet away from the plane of fire is called derivation.
It increases disproportionately to the flight distance of the bullet, as a result of which the latter deviates more and more to the side of the intended target and its trajectory is a curved line. The direction of the bullet deflection depends on the direction of the rifling of the barrel of the weapon: when the barrel is rifling on the left side, the derivation takes the bullet to the left side, and on the right side - to the right.
At firing distances up to 300 meters inclusive, derivation has no practical significance.
| Distance, m | Derivation, cm | Thousandths (horizontal adjustment of the sight) | Aiming point without corrections (SVD rifle) |
| 100 | 0 | 0 | sight center |
| 200 | 1 | 0 | Same |
| 300 | 2 | 0,1 | Same |
| 400 | 4 | 0,1 | left (from the shooter) eye of the enemy |
| 500 | 7 | 0,1 | on the left side of the head between the eye and ear |
| 600 | 12 | 0,2 | left side of the enemy's head |
| 700 | 19 | 0,2 | over the center of the epaulette on the opponent's shoulder |
| 800 | 29 | 0,3 | without corrections, accurate shooting is not performed |
| 900 | 43 | 0,5 | Same |
| 1000 | 62 | 0,6 | Same |
Ministry of Internal Affairs for the Udmurt Republic
Center vocational training
TUTORIAL
FIRE PREPARATION
Izhevsk
Compiled by:
Combat and combat instructor physical training Center for Professional Training of the Ministry of Internal Affairs for the Udmurt Republic Police Lieutenant Colonel Gilmanov D.S.
This manual "Fire Training" was compiled on the basis of the Order of the Ministry of Internal Affairs of the Russian Federation dated November 13, 2012 No. 1030dsp "On approval of the Manual on the organization of fire training in the internal affairs bodies Russian Federation", "Instructions on shooting business"9 mm Makarov pistol", "Manuals for 5.45 mm Kalashnikov assault rifle" in accordance with the training program for police officers.
Tutorial"Fire training" is intended for use by students of the Vocational Training Center of the Ministry of Internal Affairs for the Udmurt Republic in the classroom and self-training.
instill skills independent work With methodological material;
Improve the "quality" of knowledge on the design of small arms.
The textbook is recommended for students studying at the Vocational Training Center of the Ministry of Internal Affairs for the Udmurt Republic when studying the subject "Fire Training", as well as for police officers for professional service training.
The manual was considered at a meeting of the cycle of combat and physical training of the CPT of the Ministry of Internal Affairs for SD
Protocol No. 12 dated November 24, 2014.
Reviewers:
colonel of the internal service Kadrov V.M. - Head of the Service and Combat Training Department of the Ministry of Internal Affairs for the Udmurt Republic.
Section 1. Basic information from internal and external ballistics…………………..………….…………...... 4
Section 2. Shooting accuracy. Ways to improve it…………………………………….………………………………………………………………………………………….
Section 3. Stopping and penetrating action of a bullet………………………………………………………...........6
Section 4. Purpose and arrangement of parts and mechanisms of the Makarov pistol………………...................................................6
Section 5. Purpose and arrangement of parts and mechanisms of the pistol, cartridges and accessories…………...7
Section 6. Operation of parts and mechanisms of the pistol……………………………………………………..………………..9
Section 7 Procedure incomplete disassembly PM…………………………………………………………....……..............12
Section 8. Assembly order of the PM after incomplete disassembly…………………………………………………….…....12
Section 9. Operation of the PM fuse…….……………………………………………………………………..…..…..12
Section 10. Pistol Delays and How to Eliminate Them…………………………………..…..…..13
Section 11. Inspection of the gun in assembled form………………………………………………………………........….13
Section 12
Section 13. Pistol shooting techniques………………………………………………………………..……..….15
Section 14 Appointment and combat properties Kalashnikov assault rifle AK-74 ………………………………………21
Section 15. The device of the machine and the operation of its parts ……………………………………………..……………..……22
Section 16. Dismantling and assembly of the machine………………………………………………………………………….…...23
Section 17. The principle of operation of the Kalashnikov assault rifle…………………………………………………………………..23
Section 18. Safety measures during firing…………………………………………………………...24
Section 19. Safety measures for handling weapons in daily work activities……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….
Section 20. Cleaning and Lubricating the Gun………………………………….…………………………………………………25
Section 21 ....26
Applications………..…………………………………………………………………………………………………..30
References………….…………………………..………………………………………………………………..34
Basic information from internal and external ballistics
firearms called a weapon in which to eject a bullet (grenade, projectile) from the barrel of a weapon with the energy of gases generated during the combustion of a powder charge.
small arms is the name of the weapon from which the bullet is fired.
Ballistics- a science that studies the flight of a bullet (projectile, mine, grenade) after a shot.
Internal ballistics- a science that studies the processes that occur when a shot is fired, when a bullet (grenade, projectile) moves along the bore.
Shot is called the ejection of a bullet (grenades, mines, projectile) from the bore of a weapon by the energy of gases formed during the combustion of a powder charge.
When fired from small arms, the following phenomenon occurs. From the impact of the striker on the primer of a live cartridge sent into the chamber, the percussion composition of the primer explodes and a flame forms, which through the seed holes in the bottom of the sleeve penetrates to the powder charge and ignites it. When a powder (combat) charge is burned, a large amount of highly heated gases are formed, which create high pressure in the bore on:
the bottom of the bullet
the bottom and walls of the sleeve;
The walls of the trunk
lock.
As a result of the pressure of gases on the bottom of the bullet, it moves from its place and crashes into the rifling; rotating along them, it moves along the bore with a continuously increasing speed and is thrown outward in the direction of the axis of the bore.
The pressure of gases on the bottom of the sleeve causes the movement of the weapon (barrel) back. From the pressure of gases on the walls of the sleeve and the barrel, they are stretched (elastic deformation), and the sleeve, tightly pressed against the chamber, prevents the breakthrough of powder gases towards the bolt. At the same time, when fired, an oscillatory movement (vibration) of the barrel occurs and it heats up. Hot gases and particles of unburned gunpowder flowing from the bore after the bullet, when they meet with air, generate a flame and a shock wave. The shock wave is the source of sound when fired.
The shot occurs in a very short period of time (0.001-0.06 s.). When fired, four consecutive periods are distinguished:
Preliminary;
First (main);
The third (the period of the consequences of gases).
Preliminary the period lasts from the beginning of the burning of the powder charge to the complete cutting of the shell of the bullet into the rifling of the barrel.
The first (basic)the period lasts from the beginning of the movement of the bullet until the moment of complete combustion of the powder charge.
At the beginning of the period, when the speed of movement along the bore of the bullet is still low, the amount of gases grows faster than the volume of the bullet chamber, and the gas pressure reaches its maximum value (Pm = 2.800 kg / cm² of the cartridge of the 1943 model); this is pressure called maximum.
The maximum pressure for small arms is created when the bullet passes 4-6 cm of the path. Then, due to the rapid increase in the speed of the bullet, the volume of the bullet space increases faster than the influx of new gases, and the pressure begins to fall. By the end of the period, it is about 2/3 of the maximum, and the speed of the bullet increases and is 3/4 of the initial speed. The powder charge completely burns out shortly before the bullet leaves the bore.
Second the period lasts from the moment of complete combustion of the powder charge until the moment the bullet leaves the bore.
From the beginning of this period, the influx of powder gases stops, however, highly compressed and heated gases expand and, putting pressure on the bullet, increase its speed.
The third period (the period of the consequences of gases ) lasts from the moment the bullet leaves the bore until the moment the action of powder gases on the bullet ceases.
During this period, powder gases flowing out of the bore at a speed of 1200-2000 m/s continue to act on the bullet and impart additional speed to it. The bullet reaches its maximum speed at the end of the third period at a distance of several tens of centimeters from the muzzle of the barrel. This period ends at the moment when the pressure of the powder gases at the bottom of the bullet is balanced by air resistance.
starting speed - the speed of the bullet at the muzzle of the barrel. For the initial speed, the conditional speed is taken, which is slightly more than the muzzle, but less than the maximum.
As the muzzle velocity increases, the following happens::
· increases the range of the bullet;
· increases the range of a direct shot;
· the lethal and penetrating effect of the bullet increases;
· the influence of external conditions on its flight is reduced.
The muzzle velocity of a bullet depends on:
- barrel length;
- bullet weight;
- powder charge temperature;
- powder charge moisture;
- the shape and size of the grains of gunpowder;
- powder loading density.
External ballistics- this is a science that studies the movement of a bullet (projectile, grenade) after the cessation of the action of powder gases on it.
Trajectory – a curved line that describes the center of gravity of a bullet during flight.
Gravity causes the bullet to gradually descend, and the force of air resistance gradually slows down the movement of the bullet and tends to overturn it. As a result, the speed of the bullet decreases, and its trajectory is an unevenly curved curved line in shape. To increase the stability of the bullet in flight, it is given a rotational motion due to the rifling of the bore.
When a bullet is flying in the air, it is affected by various atmospheric conditions:
· air temperature;
· air movement (wind) of various directions.
With an increase in atmospheric pressure, the air density increases, as a result of which the air resistance force increases, and the range of the bullet decreases. And, conversely, with a decrease in atmospheric pressure, the density and force of air resistance decrease, and the range of the bullet increases. Corrections for atmospheric pressure when shooting are taken into account in mountainous conditions at an altitude of more than 2000 m.
The temperature of the powder charge and, consequently, the burning rate of the powder depend on the ambient temperature. The lower the temperature, the slower the gunpowder burns, the slower the pressure rises, the slower the speed of the bullet.
With an increase in air temperature, its density and, consequently, the drag force decrease, and the range of the bullet increases. Conversely, as the temperature decreases, the density and air resistance force increase, and the range of the bullet decreases.
Exceeding the line of sight - the shortest distance from any point of the trajectory to the line of sight
The excess can be positive, zero, negative. The excess depends on design features weapons and ammunition used.
Sighting range – this is the distance from the departure point to the intersection of the trajectory with the line of sight
Direct shot - a shot in which the height of the trajectory does not exceed the height of the target throughout the entire flight of the bullet.
