Text by Vladimir Tikhomirov
Quite recently we had the opportunity to join hunting with rifled weapons. At first these were the Mosin rifle (and carbine) and small-caliber fishing carbines. It’s not for nothing that on the covers of the popular book by M.M.
Bluma about hunting weapons - photographs of these very “hunting” tools. When about 12 years ago one of Sauer’s representatives asked me what calibers of rifled hunting weapons we consider “average”, I did not quite understand what he was talking about. A little later, foreign manufacturers of rifled hunting weapons and ammunition for them came to our market. I think that I was not the only one who experienced something similar to shock from the abundance of cartridges and bullets for them. I can’t boast that I finally managed to properly sort out all this diversity, but I managed to build some systematization for myself. I hope that these considerations will also be useful to readers who already have rifled weapons in their safe when choosing cartridges. Since the available weapons are not only the caliber, but also the type of cartridge, the “armed” person only has to decide on the type of bullets.
What is the demand for bullets?
The life of a bullet begins with its manufacture. After some time, each of them finds a place in its cartridge. At this stage, it is at risk of asymmetric deformation when securing the cartridge case in the muzzle. If this happens (and with our native patrons this “happens” almost always), then you can forget about decent accuracy. Of course, in nice houses this never happens. The bullets have a circular groove - a canelure - into which the edge of the cartridge case is rolled.
TIG - Torpedo - Ideal - Geschoss
After that, the bullet waits for its “X” moment for quite a long time. When it comes and the cartridge is in the chamber, the bullet must press its head tightly against the beginning of the transition cone. This is far from an easy moment. The fact is that if the length of the cartridge case is standardized, then the length of the assembled cartridge varies due to the different length of the bullet. For example, .308 Winchester cartridge with TMR bullets
(7.1 g) has a length of 62.5 mm, and with TUG type bullets (11.7 g) - 66.6 mm. That is why chambers in weapons designed for ultra-precise shooting are made for a specific bullet. When the cartridge is fully chambered, the bullet should not “bite”, since in this case it may not fit correctly into the rifling of the barrel. There should not be any free play in front of it before the rifling. In this case, when fired there will be an impact on the transition cone, which leads to a decrease in accuracy. When entering the barrel, the bullet must take the shape of its cross-section so that there is no breakthrough of powder gases. At this stage main task get maximum speed. It is very important that the bullets from one batch of cartridges have a minimum spread in speed. This is a necessary component of high accuracy.
For some time after leaving the barrel, the powder gases continue to act on the bullet. In rifled weapons their pressure is about 100 atmospheres. Moreover, when the bullet leaves the barrel, it drops sharply, and conditions are created for the explosive burning of gunpowder. While there was high blood pressure gases, the combustion process was inhibited. Thus, when leaving the barrel, a high pressure of powder gases is formed behind the bullet, which overtakes the bullet. To prevent the bullet from tumbling, it must have a shape that allows it to maintain a stable trajectory for some time during reverse flow. Sometimes they talk about reverse ballistics. During the main part of the trajectory, the bullet is required to remain in the firing plane without turning into a three-dimensional spiral.
Interaction of a bullet with the target’s body – special question, which we will discuss in the final part.
T.U.G. - Torpedo Universal Geschos
The most important properties of bullets
It would probably be more correct to rank these properties by importance, but let's start with a simple one - bullet mass. For a given caliber, this property is determined by the shape (mainly length) and design of the bullet. The vast majority of modern bullets are quite complex. Their components are made from materials having different densities.
It so happens that abroad the mass of bullets (and powder charges) is measured in grains.
This word itself comes from the Latin granum - grain, and today it is a linguistic monument to the old pharmaceutical system of weights. In Russia, its basic unit was the apothecary pound (358.323 g), which was divided into 12 ounces (29.860 g). An ounce was divided into 8 drachmas (3.732 g), each of which contained three scruples (1.244 g). Scruple was divided into 20 grains. From here our grain is equal to 0.0622 g. However, Western units of weight were based not on ours, but english pound(373.241 g) Therefore, 1 grain accepted in the arms industry is equal to 64.8 mg or 0.0648 g. It is this number that needs to be remembered to convert grains to grams. You can also remember reciprocal – 15,43.
How many grains does 1 gram contain?
At first it was impossible to imagine that countless types of bullets were produced for the .30-06 Springfield cartridge, weighing from 3.6 to 16.2 grams. True, in “factory” cartridges the lightest bullet for this caliber weighs 6.8 grams, and the heaviest – 14.3. Extremely light and heavy bullets are designed for self-loading cartridges. Let's look at what bullet mass affects. The first, of course, is speed. In the cartridge specific type Always constant quantity gunpowder of a certain brand. (It is clear that in cartridges with more than centuries-old history, like our 7.62X54 R or the American 30-06 Springfield, the gunpowder was changed several times.) Therefore, the pressure, and therefore the force accelerating the bullet, will be the same to a first approximation. According to Newton's second law, the acceleration that a body acquires under the influence of a force is inversely proportional to its mass. Therefore, lighter bullets leave the gun barrel at a higher speed. For example, let’s compare the speeds of SF (weight 10.0 g) and Silvertip (weight 14.3 g) bullets for the .300 Win cartridge. Mag. The muzzle velocities of these bullets are 950 and 817 m/s, respectively. It is clear that if the mass of the bullets differs by half (which quite realistically exists in caliber .30-06), then the speeds will differ significantly. For a bullet weighing 6.8, the initial speed is about 1000 m/s, and for 14.3 - about 700. On the other hand, large mass provides greater stability of the bullet along the trajectory. Since the “frontal” aerodynamic drag of a bullet depends on its diameter, ballistics uses a parameter called lateral load- the ratio of the mass of the bullet to its cross section. Bullets with a higher lateral load have a flatter trajectory.
TOG - Torpedo Optimal Geschos
More precisely, the ability of bullets to maintain velocity as they move away from the muzzle is described by ballistic coefficient. The higher it is, the slower the speed along the trajectory drops. This depends mainly on the profile of the bullet. A heavy bullet is also good because it is less easily blown away by side winds.
In connection with the mass of the bullet, there are two more important points to consider. A bullet in a rifled barrel acquires not only translational, but also rotational motion with a high angular velocity (up to 3000 revolutions per second). The gyroscopic effect tends to maintain (preserve) the position of the bullet’s rotation axis on the trajectory. But since the trajectory is not a straight line, but a parabola, it deviates more and more downward from the direction of the bullet’s axis of rotation at the moment it leaves the barrel. The aerodynamic flow begins to lift the head of the bullet. To prevent the bullet from hitting the target sideways, it is necessary to change the position of its rotation axis so that it coincides with the tangent to the trajectory. This is the task that the correct distribution of the mass of the bullet along its axis should cope with. To prevent the incoming air from knocking over the bullet, it must have a center of gravity shifted forward relative to the geometric center. In this case they talk about positive sweep. A relatively light rear section of the bullet will produce a greater and opposite torque than the front section.
Second important point, associated with mass, lies in the fact that the bullet, moving in the barrel, unwinds behind the generatrices (outer surface). Having flown out of the barrel, it continues to rotate freely. Moreover, if the longitudinal center of mass did not coincide with geometric center, the bullet turns into a rotating eccentric. Moreover, it does not fly along a trajectory, but along a three-dimensional spiral, the radius of which increases as it moves away from the muzzle. To avoid this effect, “in good houses” bullets are checked for dynamic balance approximately the same as what is done with car wheels. The problem of balancing bullets is not as simple as it might seem at first glance. Most modern bullets consist of several parts and ensuring their alignment is not at all easy. Due to high angular velocity rotation of the bullet, even small variations in density within the same material affect its balance.
Bullet and barrel survivability.
When hunting with a smoothbore weapon, you don’t have to think about the survivability of the barrel. Here, there is practically no change in size, and this does not affect the shotgun battle. It's a completely different story when we deal with rifled weapons. Modern gunpowder and small-caliber bullets, flying at speeds of about 1000 m/s, make barrels unsuitable for accurate shooting after several hundred shots. Use of alloy steels with high temperature Holidays only slightly reduce the severity of the problem. In larger calibers, as barrel pressures and bullet velocities decrease, barrel life is slightly higher. In the literature for .300 Win .Mag. survivability is given as less than 2000 rounds. Of course, this is a lot, but it still makes you think about saving the barrel by selecting sparing bullets.
As soon as the pressure of the powder gases begins to push the bullet out of the cartridge case, the barrel fields begin to be pressed into its leading part. Because solids are practically incompressible, the bullet tends to stretch along its axis. This deformation, consisting of plastic (irreversible) and elastic (reversible) components, “eats” a significant part of the energy of the powder gases. It is important that the bullet body completely covers the cross-section of the barrel bore, preventing powder gases from passing through the rifling. Since bullets, depending on the design, are deformed differently, there are three options for the ratio of the diameter of the leading part of the bullet and the bore along the rifling. The most pliable bullets are made fuller than the bore in rifling and they have to extend significantly in length as they pass. The diameter of bullets of moderate compliance is made equal to the diameter of the barrel bore along the rifling. In the trunk they are also forced to stretch due to the volume of material squeezed out by the fields. The stiffest bullets have a slightly smaller size than the barrel along the rifling, which is filled when fired due to the material squeezed out by the fields. That is why it is important to strictly adhere to dimensional tolerances in the barrels. As soon as the barrel becomes freer, breakthroughs of powder gases begin to increase noticeably, and after this the accuracy of the battle decreases. With significant wear, bullets begin to break off the rifling. As a result, the accuracy drops catastrophically, and this means the end of the life of the barrel.
When the leading part of the bullet completely enters the bore, it further promotion will be hampered by the friction force, which depends on the coefficient of friction and the force pressing the rubbing bodies. In our case, this is the elastic force of a deformed bullet. Reducing friction between the surface of the bullet and the bore is a constant concern of gunsmiths. Barrel manufacturers make every effort to achieve of the highest purity surfaces of fields and grooves. They are carefully ground and polished, turning special attention at the bullet entrance - the place where the fields are pressed into the body of the bullet. Bullet manufacturers strive to reduce the friction of the bullet in the barrel to reduce temperature and reduce wear. It is clear that the more pliable the bullet body and the softer the outer coating, the higher the barrel life. In terms of harmlessness to barrels, lead bullets are closest to chewed blotting paper. On opposite side This row contains steel-jacketed bullets. Fortunately (or perhaps to our misfortune), such bullets are produced en masse only in one country (guess which). Now, as something progressive, we are introducing a bimetallic shell - steel, coated with a very thin layer tombaka (copper with zinc added up to 10%). But this increases the properties of bullets incomparably less than the price. Such a shell still has high rigidity. Bullets with thick transverse partitions are difficult to deform (Fail Safe, Swift-A-Frame, Partition Gold, etc.)
It’s a completely different matter when the bullet shell is entirely made of tombac, and under it the core is made of soft lead.
To reduce bullet friction in the barrel, anti-friction coatings are used. The most effective way is to coat the tombac shell with a thin layer of molybdenum disulfide. The words “Mollycoated bullets” (sometimes simply Molly) are added to the names of such bullets. The effect of using this salt is associated with its layered-lamellar structure. Aerosols, pastes, and powders are produced on its basis. Hunters can easily apply this coating themselves.
Barnes Bullets produces bullets coated with fluorine-containing polymers. It can be expected that this coating will become widespread due to its low cost and ease of application. Remington also produces cartridges with several types of bullets coated with a thin layer of proprietary Lubalox plastic. Anti-friction coatings reduce the maximum pressure in barrels, reduce the amount of soot, allow the bullet to accelerate more strongly, provide better accuracy and increase barrel life.
Bullet and target
The first thing, of course, is that the bullet must hit the target. To do this, it must be well balanced and have optimal contours. Most often, fully jacketed bullets or bullets with a sharp nose have these properties. They are usually used by sports shooters and varminters. In these cases, there are usually no problems with bullet energy. Shooting large animals like a bear or wild boar is a completely different matter. Here two problems become relevant: the sufficiency of the bullet’s energy and its expansiveness.
Eat empirical pattern: to reliably kill an animal, it is necessary that the energy of the bullet, expressed in kgm, numerically exceed its weight, expressed in kilograms. If we express energy in Joules, which is more correct, then the “bullet” should have 10 more joules than the animal’s kilograms. Recall that energy is proportional to the square of the speed and the mass of the bullet. Therefore, the lethality of a bullet drops very quickly with firing distance. For example, let’s look at the data for a bullet weighing 11 g from the .300 Win cartridge. Mag. (with a trunk length of 60 cm). The muzzle energy of a bullet, equal to 5016 J, at a distance of 300 meters drops almost by half, to 2403 J. The energy of the bullet itself is significant only in those cases when it is completely surrendered to the beast. If an animal is pierced through and through by a small-caliber bullet, and at the same time it leaves the body at high speed, then this may turn out to be almost harmless for it. It is very important that the bullet loses all its energy in the animal’s body, and penetrates deep into the body, to the vital organs.
Therefore, bullets are optimal for hunting large animals large mass with controlled expansion. When hitting a target, the head of such bullets is deformed, forming a “fungus” without dividing into small fragments. This creates a deep wound channel of large diameter. There are known cases when overly expansive bullets, hitting a wild boar, turned around and tore into small pieces in its thickness, not reaching vital organs. If you have to shoot a fox or arctic fox from the same carbine, then an expansive bullet will be completely unnecessary. A fully jacketed bullet is more useful here. Let there be two small holes in the skin. This is better than one being small and the other the size of a cap.
It is more correct to shoot with the same bullet at a small roe deer. If an expansive bullet hits it, there will be an offensively large amount of “burnt” meat, which good people don't eat.
Bullet designs
The simplest in design - monolithic bullets. Probably by chance, they ended up at the beginning and end of the caliber row. For sport shooting from small-caliber weapons
(5.6 mm) and small fur hunting uses all-lead bullets. They are usually used in sports and sport-hunting cartridges and have velocities of 320 – 350 m/s. Sometimes all-lead bullets are found in high-velocity cartridges (velocities up to 450 m/s). In these cases, they are most often covered with a layer of sputtered copper.
Sometimes holes are made in the head of such bullets to increase expansion (Hollow Point). There is approximately the same hole in the head of the X - bullet, the body of which is made of brass.
The ABC bullet can also be classified as a monolithic bullet. It is made of tombak, and in the upper (nose) part there is a lead cone. There are cross-shaped cuts in the head part, along which it opens when it hits the target.
To hunt the largest African animals in large caliber cartridges, an all-metal bullet made of copper alloys"Solid". It is remarkable because it creates a very deep wound channel.
The second very common type of bullets can probably be called completely jacketed bullets. As a rule, these bullets have military roots. They behave well on the trajectory and do not break up the game too much. Such bullets are used to shoot game birds (where permitted), animals for scientific research and ordinary hunting game, when the caliber of the weapon allows it. German manufacturers call such bullets “Vollmantel-Geschoss”, and English-speaking ones call them “Full Metal Jacket” or “Metal Case”. Typically, jacketed bullets are used in sport hunting and sniper shooting. Such bullets consist of a lead core and a tompak shell (in the Russian version, steel or bimetallic). For some bullets, the shell in the nose is made several times thicker than the leading part. In our old sniper bullet, the core is made of a composite of steel and lead. For the largest animals, a special jacketed bullet AGS-Solid has been developed, in which a tungsten carbide core (density 1.3 higher than that of lead) is enclosed in a full bronze jacket.
Among the bullets intended for hunting, the most diverse range is semishell bullets Their distinctive feature- open bullet head. The shell of such bullets often has greatest thickness, and as it approaches the nose it becomes thinner. In the head part there may be a cylindrical void or, on the contrary, a wedging cone made of bronze (Bronse Point bullet) or plastic (Plastic Point, Nosler Ballistic Tip). Sometimes the head part is covered with a cap various forms and materials. Such bullets include Silvertip -Expanding (aluminum cap), H -Mantel -Kupferhohlspitzgeschoss (copper cap), Torpedo -S bullet. The main efforts of bullet developers are aimed at obtaining controlled expansion. Optimally, the bullet should expand as much as possible and at the same time penetrate deeply enough into the animal’s body. Ideally, it should maintain its integrity. Limitation of deformation starting from the head part reaches in various ways. In a Starkmantel bullet (reinforced casing), the thickness of the tombac casing constantly increases from the bare head to the bottom. Thus, the development of mushroom-shaped deformation of the head part of the lead core with increasing force is prevented by the shell. The casing of this bullet has a cutting edge at the base of the head, designed to cut a wide hole in the body of the animal. This edge is present in many jacketed bullets.
A common technique for limiting the deformation of a soft core is deep transverse compression of the shell and core. Usually this place limits the area of development of the mushroom deformity. This type of bullet casing is called H-Mantel in German. A similar effect is achieved in D-Mantel type bullets, which have a double jacket at the bottom of the bullet.
A common technique is to divide the core into two parts with a thick partition, representing one whole with the shell (Nosler Partition, Swift a-fram).
In two very popular bullets developed by Brennke (TUG - Torpedo Universal Geschoss and TIG - Torpedo Ideal Geschoss), the core consists of two lead parts, but the first is made of soft lead, and the second of hard (with the addition of antimony).
Good luck to you!
To some approximation, the behavior of powder gases can be described using the Mendeleev ¾ Clapeyron equation. This allows you to qualitatively analyze the phenomenon of the shot and plot the gas pressure dependence p bullet speed v out of the way l, passed by it in the barrel bore (see Fig.).
Let's look at how the shooting process occurs. Its duration can be divided into the following successive periods: preliminary¾ from the start of combustion of the powder charge until the bullet casing is completely inserted into the rifling of the barrel; first¾ from the start of the bullet moving along the barrel to complete combustion powder charge; second¾ from the moment of complete combustion of the powder charge until the bullet leaves the barrel; third¾ from the moment the bullet leaves until its speed stops increasing.
Let's consider how the pressure of the powder gas changes during a shot (curve I in the figure).
Preliminary period. During combustion of the charge, powder gas is formed. Its pressure can be expressed by the formula:
(1)where T, V and m ¾ respectively the temperature, volume and mass of the powder gas, M ¾ its molar mass, R ¾ universal gas constant. Since the volume of the gas does not change, but the temperature and mass increase sharply, the gas pressure will increase according to the law:
,where C ¾ constant. The pressure of the powder gases will increase until the bullet moves.
First period. It can be roughly divided into three half-periods. Let's look at them one by one.
1. Mass of powder gas m increases faster than volume V bullet space (the volume enclosed between the bottom of the bullet and the bottom of the cartridge case). Considering that
(S ¾ cross-sectional area of the bore, l¾ path of the bullet in the barrel), the change in gas pressure in the first sub-period can be represented graphically in the form of section 1-2 of curve I.
2. The rate of increase in the mass of the powder gas becomes close to the speed of the bullet, or, which is the same thing, to the rate of change in volume V. Then formula (1) takes the form
,where C 1 ¾ is a constant value. Graphically, the change in pressure during this sub-period can be represented as section 3-4 of curve I.
3. Volume V Due to the rapid increase in bullet speed, the bullet space grows much faster than the mass m the influx of powder gas, and the change in mass can be neglected. Then formula (1) will take the form:
,where C 2 ¾ is a constant value. The change in gas pressure during this sub-period can be represented as section 5-6 of curve I.
Intermediate processes between subperiods can be approximately depicted by the corresponding sections 2-3 and 4-5 of curve I.
Second period. Since the entire powder charge has already burned, the mass of the gas does not change. Then formula (1) takes the form
,where C 3 ¾ is a constant value. The change in pressure can be represented by section 6-7 of curve I.
Third period. Part of the gas escapes from the barrel bore following the bullet, when it meets air it forms a flame and shock wave. Therefore, the mass of gas m decreases. Since the volume of gas increases, then, according to formula (1), a sharp drop in gas pressure occurs (section 7-8 of curve I). This decrease occurs until the pressure of the powder gas at the bottom of the bullet is balanced by air resistance.
A graph of changes in bullet speed in the barrel bore (curve II in Fig.) can be constructed if we assume that the force acting on the bullet from the powder gases is large more power resistance, friction force, etc.
During the preliminary period, the speed of the bullet does not change. In other periods, the acceleration of the bullet is proportional to the pressure. Indeed, the force acting on the bullet is:
,Where p¾ powder gas pressure, S¾ cross-sectional area of the bore. Therefore, if the bullet mass m, then its acceleration
.Since the gas pressure in the barrel bore at all times is much greater than atmospheric pressure, the acceleration of the bullet will be greater than zero, i.e. It will move accelerated.
In the first sub-period, the acceleration increases, therefore, the speed of the bullet will increase sharply. Graphically, this change in speed can be represented as section 1-2 of curve II. In the second subperiod, the acceleration almost does not change, so the movement of the bullet will be close to uniformly accelerated (section 3-4 of curve II). In the third subperiod, the acceleration of the bullet decreases, but remains positive, therefore, the increase in bullet speed decreases (section 5-6 of curve II). In the second and third periods, there is a further decrease in acceleration, which corresponds to a decrease in the increase in speed (section 7-8 of curve II).
You can study the initial velocity of a bullet using conservation laws. Initial speed The bullet is called the speed with which it leaves the barrel. The law of conservation of energy for the phenomenon of a shot can be written as follows:
. (2)
Here E 1 ¾ the energy released during the combustion of gunpowder, E 2 ¾ kinetic energy bullets at the moment of departure from the barrel, E 3 ¾ kinetic energy of small arms, E 4 ¾ energy carried away by ejected powder gases, used to heat the barrel, etc.
Obviously,
(3)(q¾ heat of combustion of gunpowder, m 1¾ its mass);
(4)(m 2¾ bullet mass, V¾ its speed at the moment of departure from the barrel);
Page 1
Physical Basics shot phenomena
To some approximation, the behavior of powder gases can be described using the Mendeleev ¾ Clapeyron equation. This makes it possible to qualitatively analyze the phenomenon of a shot and construct graphs of the dependence of the gas pressure p of the bullet speed v on the path l traversed by it in the barrel bore (see Fig.).
Let's look at how the shooting process occurs. Its duration can be roughly divided into the following successive periods: preliminary ¾ from the start of combustion of the powder charge until the bullet casing is completely embedded in the rifling of the barrel; the first ¾ from the beginning of the bullet’s movement along the barrel until the complete combustion of the powder charge; the second ¾ from the moment of complete combustion of the powder charge until the bullet leaves the barrel; the third ¾ from the moment the bullet leaves until its speed stops increasing.
Let's consider how the pressure of the powder gas changes during a shot (curve I in the figure).
Preliminary period. During combustion of the charge, powder gas is formed. Its pressure can be expressed by the formula:
where T, V and m ¾ are the temperature, volume and mass of the powder gas, respectively, M ¾ its molar mass, R ¾ the universal gas constant. Since the volume of the gas does not change, but the temperature and mass increase sharply, the gas pressure will increase according to the law:
where C ¾ is a constant value. The pressure of the powder gases will increase until the bullet moves.
First period. It can be roughly divided into three half-periods. Let's look at them one by one.
1. The mass of powder gas m increases faster than the volume V of the bullet space (the volume enclosed between the bottom of the bullet and the bottom of the cartridge case). Considering that
(S ¾ cross-sectional area of the barrel bore, l ¾ path of the bullet in the barrel bore), the change in gas pressure in the first sub-period can be represented graphically in the form of section 1-2 of curve I.
2. The rate of increase in the mass of the powder gas becomes close to the speed of the bullet, or, which is the same thing, to the rate of change in volume V. Then formula (1) takes the form
where C1 ¾ is a constant value. Graphically, the change in pressure during this sub-period can be represented as section 3-4 of curve I.
3. The volume V of the bullet space, due to the rapid increase in bullet speed, grows much faster than the mass m of the influx of powder gas, and the change in mass can be neglected. Then formula (1) will take the form:
where C2 ¾ is a constant value. The change in gas pressure during this sub-period can be represented as section 5-6 of curve I.
Intermediate processes between subperiods can be approximately depicted by the corresponding sections 2-3 and 4-5 of curve I.
Second period. Since the entire powder charge has already burned, the mass of the gas does not change. Then formula (1) takes the form
where C3 ¾ is a constant value. The change in pressure can be represented by section 6-7 of curve I.
Third period. Part of the gas escapes from the bore after the bullet, and when it meets air, it forms a flame and a shock wave. Consequently, the gas mass m decreases. Since the volume of gas increases, then, according to formula (1), a sharp drop in gas pressure occurs (section 7-8 of curve I). This decrease occurs until the pressure of the powder gas at the bottom of the bullet is balanced by air resistance.
A graph of changes in the speed of a bullet in the barrel bore (curve II in Fig.) can be constructed if we assume that the force acting on the bullet from the powder gases is much greater than the resistance force, friction force, etc.
During the preliminary period, the speed of the bullet does not change. In other periods, the acceleration of the bullet is proportional to the pressure. Indeed, the force acting on the bullet is:
where p ¾ pressure of powder gas, S ¾ cross-sectional area of the barrel bore. Therefore, if the mass of the bullet is m, then its acceleration
Since the gas pressure in the barrel bore is much greater than atmospheric pressure at all times, the acceleration of the bullet will be greater than zero, i.e. it will move faster.
In the first sub-period, the acceleration increases, therefore, the speed of the bullet will increase sharply. Graphically, this change in speed can be represented as section 1-2 of curve II. In the second subperiod, the acceleration almost does not change, so the movement of the bullet will be close to uniformly accelerated (section 3-4 of curve II). In the third subperiod, the acceleration of the bullet decreases, but remains positive, therefore, the increase in bullet speed decreases (section 5-6 of curve II). In the second and third periods, there is a further decrease in acceleration, which corresponds to a decrease in the increase in speed (section 7-8 of curve II).
You can study the initial velocity of a bullet using conservation laws. The muzzle velocity of a bullet is the speed at which it leaves the barrel. The law of conservation of energy for the phenomenon of a shot can be written as follows:
. (2)
Here E1 ¾ is the energy released during the combustion of gunpowder, E2 ¾ the kinetic energy of the bullet at the moment of departure from the barrel, E3 ¾ the kinetic energy of small arms, E4 ¾ the energy carried away by the ejected powder gases, used to heat the barrel, etc.
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Every year the state introduces new rules, or features in the order of completion. We closely monitor every detail and can guarantee full compliance. All data is carefully checked and is completely similar to university and state standards. All required stamps and signatures, as well as a mark in the register, make this diploma legal.
Original forms
To prepare a diploma of higher education, we use only these forms approved by the Ministry of Education of the Russian Federation. State sign forms, as well as correct filling out, make the diploma high-quality and worthy best grades the most picky experts. Not all companies have access to original forms, but they are the main thing that determines the authenticity of a document. Our diplomas have all the necessary levels of protection and will pass any test.
Information support
You can receive any information you are interested in by mail, on Skype or by phone from our specialists. The list of prices is on the website. The entire process of acquiring a diploma with entry into the register in Yekaterinburg is also outlined here. You will receive full support and professional help from our specialists. We pay close attention to each client and take into account your requirements and wishes.
What is your role?
Having decided to buy a diploma, you must fill out an application. You will be required to provide personal data, select a university, specialty and grades for the application. If you have any questions, ask our consultants. After this, we prepare a diploma for you according to all the registration rules and on real GOZNAK banks and send it with delivery to the specified address. After you are convinced of the quality of the proposed document, you make payment in full. This ends our cooperation, and all data about the transaction is erased.
Delivery and payment
Delivery within the city of Yekaterinburg is absolutely free. You can place an order by courier to your home or post office. Payment for the diploma is made after you receive it in your hands, according to the agreed amount. We do not ask for advance payment and trust our clients. High quality diplomas are conditioned by authentic forms and full compliance of completion. We do our job to make our clients happy. Our extensive experience is the key to your success. Each specialist who will prepare a diploma for you has been doing this for several years. Real meticulous professionals will prepare for you the best documents in any specialty. We have been working for more than ten years and can guarantee your success.
