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What is a sub-caliber projectile? The principle of operation of a sub-caliber projectile. Sub-caliber shells of the present and future What is the difference between sub-caliber and armor-piercing shells

Armor-piercing piercing sub-caliber projectile (arrow-shaped feathered projectile) - a type of projectile for barreled weapons, stabilized in flight due to aerodynamic forces (similar to stabilization in flight of an arrow). This circumstance distinguishes this type of ammunition from projectiles stabilized in flight by rotation due to gyroscopic forces. Arrow-shaped feathered projectiles can be used both in hunting and military hand firearms, and in cannon artillery. The main area of ​​application of such projectiles is the destruction of heavily armored vehicles (in particular, tanks). Arrow-shaped feathered projectiles are usually kinetic-action ammunition, but may also contain an explosive charge.

120 mm shots of the Israeli company IMI. In the foreground is an M829 shot (USA), manufactured by IMI under license.

Terminology

Armor-piercing feathered sub-caliber projectiles (arrow-shaped) can be abbreviated as BOPS, OBPS, OPS, BPS. Currently, the abbreviation BPS is also applied to feathered sabot arrow-shaped projectiles, although it should be correctly used to designate sabot armor-piercing projectiles of the usual elongation for rifled artillery projectiles. The name of the armor-piercing feathered arrow-shaped ammunition applicable to rifled and smoothbore artillery systems.

Device

Ammunition of this type consists of an arrow-shaped feathered projectile, the body (body) of which (or the core inside the body) is made of a durable and high-density material, and the feathering is made of traditional structural alloys. The materials most used for the body include heavy alloys (of the VNZh type, etc.) and compounds (tungsten carbide), uranium alloys (for example, the American Stabilloy alloy or the domestic analogue of the UNC alloy type). The plumage is made of aluminum alloys or steel.

With the help of annular grooves (forgings), the BOPS body is connected to a sector pallet made of steel or high-strength aluminum alloys (type V-95, V-96Ts1 and similar). A sector pallet is also called a master device (VU) and consists of three or more sectors. The pallets are fastened to each other by leading belts made of metals or plastics and in this form are finally fixed in a metal sleeve or in the body of a burning sleeve. After leaving the gun barrel, the sector pallet is separated from the body of the BOPS under the action of the oncoming air flow, breaking the leading belts, while the body of the projectile itself continues to fly towards the target. Dropped sectors, having high aerodynamic drag, slow down in the air and fall at some distance (from hundreds of meters to more than a kilometer) from the muzzle of the gun. In the event of a miss, the BOPS itself, which has low aerodynamic resistance, can fly away to a distance of 30 to more than 50 km from the muzzle of the gun.

The designs of modern BOPS are extremely diverse: the bodies of shells can be either monolithic or composite (a core or several cores in a shell, as well as longitudinally and transversely multilayered), plumage can be almost equal to the caliber of an artillery gun or sub-caliber, made of steel or light alloys. Leading devices (VU) can have a different principle of distribution of the gas pressure action vector into sectors (VU of the "expanding" or "clamping" type), a different number of places for conducting sectors, be made of steel, light alloys, and also composite materials - for example, from carbon composites or aramid composites. Ballistic tips and dampers can be installed in the head parts of the BOPS bodies. Additives can be added to the material of tungsten alloy cores to increase the pyrophoricity of the cores. Tracers can be installed in the tail parts of the BOPS.

The mass of BOPS bodies with plumage ranges from 3.6 kg in old models to 5-6 kg or more in models for advanced tank guns of 140-155 mm caliber.

The diameter of BOPS bodies without plumage ranges from 40 mm in older models to 22 mm or less in new promising BOPS with a large elongation. The elongation of BOPS is constantly increasing and ranges from 10 to 30 or more.

In the USSR and Russia, several types of BOPS are widely known, created in different times and having proper names, which originated from the name / cipher R & D . The following are BOPS in chronological order from old to new. The device and material of the BOPS body are briefly indicated:

  • "Hairpin" 3BM-23 - a small core of tungsten carbide in the head of the steel body (1976);
  • "Nadfil-2" 3BM30 - uranium alloy (1982);
  • "Hope" 3BM-27 - a small tungsten alloy core in the tail section of a steel body (1983);
  • "Vant" 3BM-33 - a monolithic body made of a uranium alloy (1985);
  • "Mango" 3BM-44 - two elongated tungsten alloy cores in a steel body jacket (1986);
  • "Lead" 3BM-48 - a monolithic body made of a uranium alloy (1991);
  • Anker 3BM39 (1990s);
  • "Lekalo" 3BM44 M? - improved alloy (details unknown) (1997); perhaps this BOPS is called the "Projectile of increased power";
  • "Lead-2" - judging by the index, a modified projectile with a uranium core (details unknown).

Other BOPS also have proper names. For example, a 100 mm anti-tank smoothbore gun has the Valshchik ammunition, a 115 mm tank gun has the Kamerger ammunition, etc.

Armor penetration indicators

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This mark is set July 13, 2012.

Comparative evaluation of armor penetration indicators is associated with significant difficulties. The assessment of armor penetration indicators is influenced by quite different test methods for BOPS in different countries, the absence in different countries of a standard type of armor for testing, different conditions for placing armor (compact or spaced), as well as constant manipulations by developers of all countries with firing distances for test armor, armor installation angles before testing, various statistical methods for processing test results. As a test material in Russia and NATO countries, homogeneous rolled armor is adopted; composite targets are used to obtain more accurate results. For example, for testing Russian shells, the P11 multilayer barrier developed at the Research Institute of Steel is used, imitating the frontal armor of the M1 Abrams tank. However, the real indicators of armor resistance composite armor and equivalent homogeneous armor still sometimes differ, which makes it difficult to accurately assess the armor penetration of a particular projectile. In addition, the characteristics of armor penetration, as well as the protection parameters of armored vehicles, are traditionally classified.

As an example, we can take the Spanish BOPS guns of the 105 mm caliber of the company "Empersa Nacional Santa Barbara", which at a speed of 1500 m / s from a distance of 5000 m pierces a NATO standard target at an angle of 60 ° from the line of fire and consisting of an armor plate 120 mm thick and ten additional armor plates of 10 mm, located at a distance of 10 mm from each other.

According to published data, an increase in the elongation of the flight part to a value of 30 made it possible to increase the relative thickness of RHA-standard rolled homogeneous armor (the ratio of armor thickness to gun caliber) to 5.0 in caliber 105 mm, and 6.8 in caliber 120 mm.

Story

The emergence of BOPS was due to the lack of armor penetration of conventional armor-piercing and sub-caliber rounds for rifled artillery in the years following World War II. Attempts to increase the specific load (that is, to lengthen their core) in sub-caliber projectiles ran into the phenomenon of loss of stabilization by rotation with an increase in the length of the projectile over 6-8 calibers. The strength of modern materials did not allow more increase in the angular velocity of the projectiles.

Arrow-shaped and feathered projectiles for ultra-long-range guns

In the rocket and artillery design bureau of the Peenemünde training ground Peenemünde-Heeresversuchsanstalt by the end of World War II, the German designer Hanns Gessner designed a series of arrow-shaped feathered projectiles of the PPG index (Peenemünder Pfeilgeschosse) for smooth-bore 310 mm caliber barrels from Krupp and Hanomag, mounted on a carriage of a 28-cm ultra-long-range railway installation K5 (E). 310 mm high explosive arrow-shaped projectile the Sprenge-Granate 4861 index had a length of 2012 mm and a mass of 136 kg. The arrow body diameter was 120 mm, the number of stabilizer feathers was 4 pcs. The initial speed of the projectile is 1420 m / s, the mass of the explosive charge is 25 kg, the firing range is 160 km. The shells were used against the Anglo-American troops in the battles near Bonn.

Experiments with arrow-shaped feathered sub-caliber projectiles for high-altitude anti-aircraft artillery were carried out at a training ground near the Polish city of Blizna under the guidance of designer R. Herman ( R. Hermann). have been tested anti-aircraft guns caliber 103 mm with a barrel length of up to 50 calibers. During the tests, it turned out that arrow-shaped feathered projectiles, which reached very high speeds due to their small mass, have insufficient fragmentation action due to the impossibility of placing a significant explosive charge in them. In addition, they demonstrated extremely low accuracy due to rarefied air at high altitudes and, as a result, insufficient aerodynamic stabilization. After it became clear that swept finned shells were not applicable for anti-aircraft fire, attempts were made to use high-velocity finned piercing shells to fight tanks. The work was stopped due to the fact that serial anti-tank and tank guns at that time had sufficient armor penetration, and the Third Reich was living out its last days.

Arrow-shaped bullets of handguns

Russia is developing arrow-shaped (needle-shaped) underwater ammunition without plumage, which is part of the SPS cartridges of 4.5 mm caliber (for the special underwater pistol SPP-1; SPP-1M) and MPS cartridges of 5.66 mm caliber (for special underwater machine APS). Unfeathered arrow-shaped bullets for underwater weapons, stabilized in water by a cavitation cavity, practically do not stabilize in the air and require not regular, but special weapons for use under water.

Currently, the most promising underwater-air ammunition, which can be fired with equal efficiency both under water at a depth of up to 50 m, and in air, are cartridges for regular (serial) machine guns and assault rifles, equipped with Polotnev's arrow-shaped feathered bullet, developed at the Federal State Unitary Enterprise "TsNIIKhM". Stabilization of Polotnev's bullets under water is carried out by the cavitation cavity, and in air - by the plumage of the bullet.

The appearance of tanks on the battlefield has become one of the major events military history of the last century. Immediately after this moment, the development of means to combat these formidable machines began. If we take a closer look at the history of armored vehicles, then, in fact, we will see the history of the confrontation between the projectile and armor, which has been going on for almost a century.

In this irreconcilable struggle, one or the other side periodically gained the upper hand, which led either to the complete invulnerability of the tanks, or to their huge losses. In the latter case, every time there were voices about the death of the tank and the "end of the tank era." However, today tanks remain the main striking force. ground forces all the armies of the world.

Today, one of the main types of armor-piercing ammunition that are used to combat armored vehicles are sub-caliber ammunition.

A bit of history

The first anti-tank shells were ordinary metal blanks, which, due to their kinetic energy, pierced tank armor. Fortunately, the latter was not very thick, and even anti-tank guns could handle it. However, already before the start of World War II, tanks of the next generation began to appear (KV, T-34, Matilda), with a powerful engine and serious armor.

Major world powers entered the Second world war, having anti-tank artillery caliber 37 and 47 mm, and finished it with guns that reached 88 and even 122 mm.

By increasing the caliber of the gun and the muzzle velocity of the projectile, the designers had to increase the mass of the gun, making it more complex, expensive, and much less maneuverable. It was necessary to look for other ways.

And they were soon found: cumulative and sub-caliber ammunition appeared. The action of cumulative ammunition is based on the use of a directed explosion that burns through tank armor, a sub-caliber projectile also does not have a high-explosive action, it hits a well-protected target due to high kinetic energy.

The design of the sub-caliber projectile was patented back in 1913 by the German manufacturer Krupp, but their mass use began much later. This ammunition does not have a high-explosive effect, it is much more like an ordinary bullet.

For the first time, the Germans began to actively use sub-caliber shells during the French campaign. They had to use such ammunition even more widely after the start of hostilities on the Eastern Front. Only using sub-caliber shells, the Nazis could effectively resist the powerful Soviet tanks.

However, the Germans experienced a serious shortage of tungsten, which prevented them from mass-producing such shells. Therefore, the number of such shots in the ammunition load was small, and the military personnel were given strict orders: to use them only against enemy tanks.

In the USSR, serial production of sub-caliber ammunition began in 1943, they were created on the basis of captured German samples.

After the war, work in this direction continued in most of the world's leading weapons powers. Today, sub-caliber ammunition is considered one of the main means of destroying armored targets.

Currently, there are even sub-caliber bullets that significantly increase the firing range of smoothbore weapons.

Operating principle

What is the basis for the high armor-piercing effect that a sub-caliber projectile has? How is it different from the usual?

A sub-caliber projectile is a type of ammunition with a caliber of the warhead that is many times smaller than the caliber of the barrel from which it was fired.

It was found that a small-caliber projectile flying at high speed has greater armor penetration than a large-caliber one. But in order to get high speed after a shot, a more powerful cartridge is needed, which means a gun of a more serious caliber.

It was possible to resolve this contradiction by creating a projectile, in which the striking part (core) has a small diameter compared to the main part of the projectile. The sub-caliber projectile does not have a high-explosive or fragmentation effect, it works on the same principle as a conventional bullet, which hits targets due to high kinetic energy.

The sub-caliber projectile consists of a solid core made of a particularly strong and heavy material, a body (pallet) and a ballistic fairing.

The diameter of the pallet is equal to the caliber of the weapon, it acts as a piston when fired, accelerating the warhead. Leading belts are installed on the pallets of sub-caliber shells for rifled guns. Typically, the pallet is in the form of a coil and is made of light alloys.

There are armor-piercing sub-caliber shells with a non-separable pallet, from the moment of the shot until the target is hit, the coil and core act as a single whole. This design creates serious aerodynamic drag, significantly reducing flight speed.

Projectiles are considered more advanced, in which, after a shot, the coil is separated due to air resistance. In modern sub-caliber projectiles, the stability of the core in flight is provided by stabilizers. Often a tracer charge is installed in the tail section.

The ballistic tip is made of soft metal or plastic.

The most important element of a sub-caliber projectile is undoubtedly the core. Its diameter is about three times smaller than the caliber of the projectile, and high-density metal alloys are used to make the core: the most common materials are tungsten carbide and depleted uranium.

Due to the relatively small mass, the core of the sub-caliber projectile immediately after the shot accelerates to a significant speed (1600 m / s). Upon impact with the armor plate, the core pierces a relatively small hole in it. The kinetic energy of the projectile is partly used to destroy armor, and partly converted into heat. After breaking through the armor, the red-hot fragments of the core and armor go out into the armored space and spread like a fan, hitting the crew and internal mechanisms of the vehicle. This creates multiple fires.

As the armor passes, the core grinds and becomes shorter. Therefore very important characteristic, which affects armor penetration, is the length of the core. Also, the effectiveness of the sub-caliber projectile is affected by the material from which the core is made and the speed of its flight.

The latest generation of Russian sub-caliber projectiles ("Lead-2") is significantly inferior in armor penetration to American counterparts. It's connected with greater length striking core, which is part of the American ammunition. An obstacle to increasing the length of the projectile (and, hence, armor penetration) is the device of automatic loaders of Russian tanks.

The armor penetration of the core increases with a decrease in its diameter and with an increase in its mass. This contradiction can be solved by using very dense materials. Initially, tungsten was used for the striking elements of such ammunition, but it is very rare, expensive, and also difficult to process.

Depleted uranium has almost the same density as tungsten, and is a virtually free resource for any country that has a nuclear industry.

At present, sub-caliber munitions with a uranium core are in service with the major powers. In the United States, all such ammunition is equipped only with uranium cores.

Depleted uranium has several advantages:

  • when passing through the armor, the uranium rod is self-sharpening, which provides better armor penetration, tungsten also has this feature, but it is less pronounced;
  • after breaking through the armor, under the action high temperatures the remnants of the uranium rod flare up, filling the armored space with poisonous gases.

To date, modern sub-caliber shells have almost reached their maximum efficiency. It can be increased only by increasing the caliber of tank guns, but this will require significant changes in the design of the tank. In the meantime, in the leading tank-building states, they are only engaged in modifying vehicles produced during the Cold War, and are unlikely to take such radical steps.

In the United States, active-rocket projectiles with a kinetic warhead are being developed. This is conventional projectile, which immediately after the shot turns on its own upper stage, which significantly increases its speed and armor penetration.

The Americans are also developing kinetic guided missile, the damaging factor of which is a uranium rod. After firing from the launch canister, the upper stage turns on, which gives the ammunition a speed of Mach 6.5. Most likely, by 2020 there will be sub-caliber ammunition with a speed of 2000 m/s and higher. This will take their efficiency to a whole new level.

Sub-caliber bullets

In addition to sub-caliber shells, there are bullets that have the same design. Very widely such bullets are used for 12 gauge cartridges.

Sub-caliber bullets of 12 caliber have a smaller mass, after being fired they receive more kinetic energy and, accordingly, have a greater flight range.

Very popular 12-gauge sub-caliber bullets are: Polev's bullet and Kirovchanka. There are other similar 12-gauge ammunition.

Video about sub-caliber ammunition

If you have any questions - leave them in the comments below the article. We or our visitors will be happy to answer them.

In World of Tanks, vehicles can be equipped with different types shells, such as armor-piercing, sub-caliber, cumulative and high-explosive fragmentation. In this article, we will consider the features of the action of each of these shells, the history of their invention and use, the pros and cons of their use in a historical context. The most common and, in most cases, regular shells on the vast majority of vehicles in the game are armor-piercing shells(BB) caliber device or sharp-headed.
According to the Military Encyclopedia of Ivan Sytin, the idea of ​​a prototype of the current armor-piercing shells belongs to the officer of the Italian fleet Bettolo, who in 1877 proposed using the so-called " bottom shock tube for armor-piercing shells"(Before that, the shells were either not equipped at all, or the explosion of the powder charge was calculated on heating the head of the projectile when it hit the armor, which, however, was far from always justified). After breaking through the armor, the damaging effect is provided by shell fragments heated to a high temperature, and armor fragments. During the Second World War, shells of this type were easy to manufacture, reliable, had a fairly high penetration, and worked well against homogeneous armor. But there was also a minus - on the inclined armor, the projectile could ricochet. The thicker the armor, the more armor fragments are formed when pierced by such a projectile, and the higher the lethal force.


The animation below illustrates the action of a chamber sharp-headed armor-piercing projectile. It is similar to an armor-piercing sharp-headed projectile, however, in the rear part there is a cavity (chamber) with an explosive charge of TNT, as well as a bottom fuse. After breaking through the armor, the projectile explodes, hitting the crew and equipment of the tank. In general, this projectile retained most of the advantages and disadvantages of the AR projectile, differing by a significantly higher armor effect and slightly lower armor penetration (due to the lower mass and strength of the projectile). During the War, the bottom shell fuses were not perfect enough, which sometimes led to a premature explosion of the shell before penetrating the armor, or to the failure of the fuse after penetration, but the crew, in case of penetration, rarely became easier from this.

Sub-caliber projectile(BP) has enough complex structure and consists of two main parts - an armor-piercing core and a pallet. The task of the pallet, made of mild steel, is to accelerate the projectile in the bore. When the projectile hits the target, the pallet is crushed, and the heavy and hard sharp-headed core made of tungsten carbide pierces the armor.
The projectile does not have a bursting charge, ensuring that the target is hit by fragments of the core and armor fragments heated to high temperatures. Sub-caliber projectiles have significantly less weight compared to conventional ones. armor-piercing shells, which allows them to accelerate in the gun barrel to significantly higher speeds. As a result, the penetration of sub-caliber shells is significantly higher. The use of sub-caliber shells made it possible to significantly increase the armor penetration of the existing guns, which made it possible to hit more modern, well-armored armored vehicles even with outdated guns.
At the same time, sub-caliber shells have a number of disadvantages. Their shape resembled a coil (there were shells of this type and a streamlined shape, but they were much less common), which greatly worsened the ballistics of the projectile, in addition, a light projectile quickly lost speed; as a result, at long distances, the armor penetration of sub-caliber shells dropped dramatically, turning out to be even lower than that of classic armor-piercing shells. During the Second World War, sabots did not work well on sloped armor, because under the influence of bending loads, the hard but brittle core easily broke. The armor-piercing effect of such shells was inferior to armor-piercing caliber shells. Sub-caliber projectiles of small caliber were ineffective against armored vehicles that had protective shields made of thin steel. These shells were expensive and difficult to manufacture, and most importantly, scarce tungsten was used in their manufacture.
As a result, the number of sub-caliber shells in the ammunition load of guns during the war years was small, they were allowed to be used only to destroy heavily armored targets at short distances. The German army was the first to use sub-caliber shells in small quantities in 1940 during the fighting in France. In 1941, faced with heavily armored Soviet tanks, the Germans switched to the widespread use of sub-caliber shells, which significantly increased the anti-tank capabilities of their artillery and tanks. However, the shortage of tungsten limited the release of shells of this type; as a result, in 1944, the production of German sub-caliber shells was discontinued, while most of the shells fired during the war years had a small caliber (37-50 mm).
In an attempt to get around the problem of tungsten shortages, the Germans produced Pzgr.40(C) sub-caliber shells with a hardened steel core and surrogate Pzgr.40(W) shells with an ordinary steel core. In the USSR, a fairly mass production of sub-caliber shells, created on the basis of captured German ones, began at the beginning of 1943, and most of the shells produced were 45 mm caliber. The production of these shells of larger calibers was limited by the shortage of tungsten, and they were issued to the troops only when there was a threat of an enemy tank attack, and a report was required for each spent shell. Also, sub-caliber shells were used to a limited extent by the British and American armies in the second half of the war.

HEAT projectile(CS).
The operating principle of this armor-piercing ammunition differs significantly from the principle kinetic ammunition, which include conventional armor-piercing and sub-caliber shells. A cumulative projectile is a thin-walled steel projectile filled with a powerful explosive - RDX, or a mixture of TNT and RDX. At the front of the projectile, explosives have a goblet-shaped recess lined with metal (usually copper). The projectile has a sensitive head fuse. When a projectile collides with armor, an explosive is detonated. At the same time, the lining metal is melted and compressed by an explosion into a thin jet (pestle), flying forward at an extremely high speed and penetrating armor. Armored action is provided by a cumulative jet and splashes of armor metal. The HEAT shell hole is small and has melted edges, which has led to a common misconception that HEAT shells “burn through” armor.
The penetration of a HEAT projectile does not depend on the velocity of the projectile and is the same at all distances. Its production is quite simple, the production of the projectile does not require the use a large number scarce metals. The cumulative projectile can be used against infantry and artillery as a high-explosive fragmentation projectile. At the same time, cumulative shells during the war years were characterized by numerous shortcomings. The manufacturing technology of these projectiles was not sufficiently developed, as a result, their penetration was relatively low (approximately corresponded to the caliber of the projectile or slightly higher) and was characterized by instability. The rotation of the projectile at high initial speeds made it difficult for the formation of a cumulative jet, as a result, the cumulative projectiles had a low initial velocity, a small effective range firing and high dispersion, which was also facilitated by the non-optimal form of the projectile head from the point of view of aerodynamics (its configuration was determined by the presence of a notch).
The big problem was the creation of a complex fuse, which should be sensitive enough to quickly undermine the projectile, but stable enough not to explode in the barrel (the USSR was able to work out such a fuse suitable for use in powerful tank and anti-tank guns, only at the end of 1944). The minimum caliber of a cumulative projectile was 75 mm, and the effectiveness of cumulative projectiles of this caliber was greatly reduced. Mass production of HEAT shells required the deployment of large-scale production of hexogen.
The most massive HEAT shells were used by the German army (for the first time in the summer-autumn of 1941), mainly from 75 mm caliber guns and howitzers. The Soviet army used cumulative shells, created on the basis of captured German ones, from 1942-43, including them in the ammunition of regimental guns and howitzers that had a low muzzle velocity. The British and American armies used shells of this type, mainly in heavy howitzer ammunition. Thus, in the Second World War (in contrast to the present time, when improved projectiles of this type form the basis of the ammunition load of tank guns), the use of cumulative projectiles was quite limited, mainly they were considered as a means of anti-tank self-defense of guns that had low initial speeds and low armor penetration by traditional projectiles (regimental guns, howitzers). At the same time, all participants in the war actively used other anti-tank weapons with cumulative ammunition - grenade launchers, aerial bombs, hand grenades.

High-explosive fragmentation projectile(OF).
It was developed in the late 40s of the twentieth century in the UK to destroy enemy armored vehicles. It is a thin-walled steel or steel-cast iron projectile filled with an explosive (usually TNT or ammonite), with a head fuse. Unlike armor-piercing shells, high-explosive shells did not have a tracer. Upon hitting the target, the projectile explodes, hitting the target with fragments and a blast wave, either immediately - a fragmentation action, or with some delay (which allows the projectile to go deeper into the ground) - a high-explosive action. The projectile is intended mainly to destroy openly located and covered infantry, artillery, field shelters (trenches, wood-and-earth firing points), unarmored and lightly armored vehicles. Well-armored tanks and self-propelled guns are resistant to high-explosive fragmentation shells.
The main advantage high-explosive projectile is its versatility. This type of projectile can be used effectively against the vast majority of targets. Also, the advantages include lower cost than armor-piercing and cumulative shells of the same caliber, which reduces the cost of combat operations and firing practice. On a direct hit on vulnerable areas(turret hatches, radiator of the engine compartment, knockout screens of the aft ammunition rack, etc.) HE can disable the tank. Also, the hit of large-caliber shells can cause the destruction of lightly armored vehicles, and damage to heavily armored tanks, consisting in cracking of armor plates, jamming of the turret, failure of instruments and mechanisms, injuries and contusions of the crew.

The term "sub-caliber projectile" is most often used in tank forces. Such shells are used along with cumulative and high-explosive fragmentation. But if earlier there was a division into armor-piercing and sub-caliber ammunition, now it makes sense to talk only about armor-piercing sub-caliber projectiles. Let's talk about what a subcaliber is and what are its key features and principle of operation.

basic information

The key difference between sub-caliber shells and conventional armored shells is that the diameter of the core, that is, the main part, is smaller than the caliber of the gun. At the same time, the second main part - the pallet - is made according to the diameter of the gun. The main purpose of such ammunition is to defeat heavily armored targets. Usually this heavy tanks and fortified buildings.

It is worth noting that the armor-piercing sub-caliber projectile has increased penetration due to the high initial flight speed. Also increased the specific pressure when breaking through the armor. To do this, it is desirable to use materials having the highest possible specific gravity as the core. For these purposes, tungsten and depleted uranium are suitable. Stabilization of the flight of the projectile is implemented by plumage. There is nothing new here, since the principle of the flight of an ordinary arrow is used.

Armor-piercing sub-caliber projectile and its description

As we noted above, such ammunition is ideal for firing at tanks. It is interesting that the subcaliber does not have the usual fuse and explosive. The principle of operation of the projectile is completely based on its kinetic energy. In comparison, it is something like a massive high-velocity bullet.

The subcaliber consists of a coil body. A core is inserted into it, which is often made 3 times smaller than the caliber of the gun. High-strength metal-ceramic alloys are used as the core material. If earlier it was tungsten, today depleted uranium is more popular for a number of reasons. During the shot, the pallet takes over the entire load, thereby ensuring the initial flight speed. Since the weight of such a projectile is less than a conventional armor-piercing one, by reducing the caliber, it was possible to increase the flight speed. These are significant values. So, a feathered sub-caliber projectile flies at a speed of 1,600 m/s, while a classic armor-piercing projectile flies at 800-1,000 m/s.

The action of a sub-caliber projectile

Quite interesting is how such ammunition works. During contact with the armor, it creates a small diameter hole in it due to high kinetic energy. Part of the energy is spent on the destruction of the target's armor, and the projectile fragments fly into the armored space. Moreover, the trajectory is similar to a divergent cone. This leads to the fact that the mechanisms and equipment of the equipment fail, the crew is affected. Most importantly, due to high degree Pyrophoric depleted uranium causes numerous fires, which in most cases leads to the complete failure of the combat unit. We can say that the sub-caliber projectile, the principle of which we have considered, has increased armor penetration at long distances. Evidence of this is Operation Desert Storm, when the US Armed Forces used sub-caliber ammunition and hit armored targets at a distance of 3 km.

Varieties of PB shells

Currently, several effective designs of sub-caliber projectiles have been developed, which are used by the armed forces of various countries. In particular, we are talking about the following:

  • With non-separable tray. The projectile passes all the way to the target as a single whole. Only the core is involved in the penetration. This solution has not received sufficient distribution due to increased aerodynamic drag. As a result, the armor penetration rate and accuracy drop significantly with the distance to the target.
  • With non-detachable tray for conical implements. The essence of this solution is that when passing through the conical shaft, the pallet is crushed. This allows you to reduce aerodynamic drag.
  • Sub-caliber projectile with detachable pallet. The bottom line is that the pallet is torn off by air forces or by centrifugal forces (with a rifled gun). This allows you to significantly reduce air resistance in flight.

About cumulatives

For the first time, such ammunition was used by Nazi Germany in 1941. At that time, the USSR did not expect the use of such shells, since their principle of operation, although known, was not yet in service. Key Feature similar projectiles was that they had high armor penetration due to the presence of instantaneous fuses and a cumulative recess. The problem, which was encountered for the first time, was that the projectile rotated during the flight. This led to the dispersion of the cumulative arrow and, as a result, reduced armor penetration. In order to exclude negative effect, it was proposed to use smoothbore guns.

Some interesting facts

It is worth noting that it was in the USSR that arrow-shaped armor-piercing sub-caliber shells were developed. This was a real breakthrough, as it was possible to increase the length of the core. Almost no armor protected from a direct hit of such ammunition. Only a successful angle of inclination of the armor plate and, consequently, its increased thickness in the reduced state could help out. In the end, BOPS had such an advantage as flat trajectory flight at a distance of up to 4 km and high accuracy.

Conclusion

A cumulative sub-caliber projectile is somewhat similar to a conventional sub-caliber. But in its body it has a fuse and an explosive. When armor is penetrated by such ammunition, a destructive effect is provided both on equipment and manpower. Currently, the most common shells for cannons with a caliber of 115, 120, 125 mm, as well as artillery pieces of 90, 100 and 105 mm. In general, this is all the information on this topic.

) and 40 tons ("Puma", "Namer"). In this regard, overcoming the armor protection of these vehicles is serious problem for anti-tank ammunition, which include armor-piercing and cumulative projectiles, rockets and rocket-propelled grenades with kinetic and cumulative warheads, as well as striking elements with an impact core.

Among them, armor-piercing sub-caliber shells and missiles with a kinetic warhead are the most effective. Possessing high armor penetration, they differ from other anti-tank munitions in their high approach speed, low sensitivity to the effects of dynamic protection, the relative independence of the weapon guidance system from natural / artificial interference, and low cost. Moreover, these types of anti-tank ammunition can be guaranteed to overcome the active protection system of armored vehicles, all in more gaining ground as a frontier for the interception of submunitions.

Currently, only armor-piercing sub-caliber shells have been adopted for service. They are fired mainly from smooth-bore guns of small (30-57 mm), medium (76-125 mm) and large (140-152 mm) calibers. The projectile consists of a two-bearing leading device, the diameter of which coincides with the diameter of the barrel bore, consisting of sections separated after departure from the barrel, and a striking element - an armor-piercing rod, in the bow of which a ballistic tip is installed, in the tail - an aerodynamic stabilizer and a tracer charge.

As the material of the armor-piercing rod, ceramics based on tungsten carbide (density 15.77 g / cc), as well as metal alloys based on uranium (density 19.04 g / cc) or tungsten (density 19.1 g / cc) are used. cc). The diameter of the armor-piercing rod ranges from 30 mm (obsolete models) to 20 mm (modern models). The higher the density of the rod material and the smaller the diameter, the greater the specific pressure exerted by the projectile on the armor at the point of its contact with the front end of the rod.

Metal rods have much greater bending strength than ceramic ones, which is very important when the projectile interacts with active protection shrapnel elements or explosive dynamic protection plates. At the same time, the uranium alloy, despite its somewhat lower density, has an advantage over tungsten - the armor penetration of the first is 15-20 percent greater due to the ablative self-sharpening of the rod in the process of penetrating armor, starting from an impact speed of 1600 m / s, provided by modern cannon shots.

The tungsten alloy begins to exhibit ablative self-sharpening starting at 2000 m/s, requiring new ways to accelerate projectiles. At a lower speed, the front end of the rod flattens out, increasing the penetration channel and reducing the penetration depth of the rod into the armor.

Along with the indicated advantage, the uranium alloy has one drawback - in the case of nuclear conflict neutron radiation penetrating the tank induces secondary radiation in the uranium, which affects the crew. Therefore, in the arsenal of armor-piercing shells, it is necessary to have models with rods made of both uranium and tungsten alloys, designed for two types of military operations.

Uranium and tungsten alloys also have pyrophoricity - the ignition of heated metal dust particles in air after breaking through the armor, which serves as an additional damaging factor. The specified property manifests itself in them, starting from the same speeds as the ablative self-sharpening. Another damaging factor is heavy metal dust, which has a negative biological effect on the crew of enemy tanks.

The leading device is made of aluminum alloy or carbon fiber, the ballistic tip and aerodynamic stabilizer are made of steel. The master device serves to accelerate the projectile in the bore, after which it is discarded, so its weight must be minimized by using composite materials instead of aluminum alloy. The aerodynamic stabilizer is subjected to thermal effects from the powder gases generated during the combustion of the powder charge, which can affect the accuracy of shooting, and therefore it is made of heat-resistant steel.

The armor penetration of kinetic projectiles and missiles is determined as the thickness of a homogeneous steel plate, installed perpendicular to the axis of the projectile flight, or at a certain angle. In the latter case, the reduced penetration of the equivalent thickness of the plate is ahead of the penetration of the plate, installed along the normal, due to the large specific loads at the entrance and exit of the armor-piercing rod into / out of the inclined armor.

Upon entering the sloping armor, the projectile forms a characteristic roller above the penetration channel. The blades of the aerodynamic stabilizer, collapsing, leave a characteristic "star" on the armor, by the number of rays of which it is possible to determine the belonging of the projectile (Russian - five rays). In the process of breaking through the armor, the rod is intensively ground off and significantly reduces its length. When leaving the armor, it elastically bends and changes the direction of its movement.

A characteristic representative of the penultimate generation of armor-piercing artillery ammunition is the Russian 125-mm separate-loading round 3BM19, which includes a 4Zh63 cartridge case with the main propellant charge and a 3BM44M cartridge case containing an additional propellant charge and the 3BM42M "Lekalo" sub-caliber projectile itself. Designed for use in the 2A46M1 gun and newer modifications. The dimensions of the shot allow it to be placed only in modified versions of the automatic loader.

The ceramic core of the projectile is made of tungsten carbide, placed in a steel protective case. The leading device is made of carbon fiber. As the material of the sleeves (except for the steel pallet of the main propellant charge), cardboard impregnated with trinitrotoluene was used. The length of the cartridge case with the projectile is 740 mm, the length of the projectile is 730 mm, the length of the armor-piercing rod is 570 mm, and the diameter is 22 mm. The weight of the shot is 20.3 kg, the cartridge case with the projectile is 10.7 kg, the armor-piercing rod is 4.75 kg. The initial speed of the projectile is 1750 m / s, armor penetration at a distance of 2000 meters along the normal is 650 mm of homogeneous steel.

The latest generation of Russian armor-piercing artillery ammunition is represented by 125-mm separate-loading rounds 3VBM22 and 3VBM23, equipped with two types of sub-caliber projectiles - respectively 3VBM59 "Lead-1" with an armor-piercing rod made of tungsten alloy and 3VBM60 with an armor-piercing rod made of uranium alloy. The main propellant charge is loaded into the 4Zh96 "Ozon-T" cartridge case.

The dimensions of the new projectiles coincide with the dimensions of the Lekalo projectile. Their weight is increased to 5 kg due to the greater density of the rod material. To disperse heavy projectiles in the barrel, a more voluminous main propellant charge is used, which limits the use of shots, including Lead-1 and Lead-2 projectiles, only new cannon 2A82, which has an enlarged charging chamber. Armor penetration at a distance of 2000 meters along the normal can be estimated as 700 and 800 mm of homogeneous steel, respectively.

Unfortunately, the Lekalo, Lead-1 and Lead-2 projectiles have a significant design flaw in the form of centering screws located along the perimeter of the supporting surfaces of the leading devices (protrusions visible in the figure on the front supporting surface and points on the surface of the sleeve ). Centering screws are used for stable management projectile in the bore, but their heads at the same time have a destructive effect on the surface of the channel.

In foreign designs of the latest generation, precision obturator rings are used instead of screws, which reduces barrel wear by a factor of five when fired with an armor-piercing sub-caliber projectile.

The previous generation of foreign armor-piercing sub-caliber projectiles is represented by the German DM63, which is part of a unitary shot for the standard 120 mm NATO smoothbore gun. Armor-piercing rod is made of tungsten alloy. The weight of the shot is 21.4 kg, the weight of the projectile is 8.35 kg, the weight of the armor-piercing rod is 5 kg. Shot length is 982 mm, projectile length is 745 mm, core length is 570 mm, diameter is 22 mm. When firing from a cannon with a barrel length of 55 calibers, the initial speed is 1730 m / s, the speed drop on the flight path is declared at the level of 55 m / s for every 1000 meters. Armor penetration at a distance of 2000 meters normal is estimated at 700 mm of homogeneous steel.

The latest generation of foreign armor-piercing sub-caliber projectiles includes the American M829A3, which is also part of the unitary shot for the standard 120-mm NATO smoothbore gun. Unlike the D63 projectile, the armor-piercing rod of the M829A3 projectile is made of a uranium alloy. The weight of the shot is 22.3 kg, the weight of the projectile is 10 kg, the weight of the armor-piercing rod is 6 kg. Shot length is 982 mm, projectile length is 924 mm, core length is 800 mm. When firing from a cannon with a barrel length of 55 calibers, the initial speed is 1640 m/s, the speed drop is declared at the level of 59.5 m/s for every 1000 meters. Armor penetration at a distance of 2000 meters is estimated at 850 mm homogeneous steel.

When comparing the latest generation of Russian and American sub-caliber projectiles equipped with armor-piercing uranium alloy cores, a difference in the level of armor penetration is visible, to a greater extent due to the degree of elongation of their striking elements - 26 times for the lead of the Lead-2 projectile and 37 times for the rod projectile М829А3. In the latter case, a quarter greater specific load is provided at the point of contact between the rod and armor. In general, the dependence of the armor penetration value of shells on the speed, weight and elongation of their striking elements is shown in the following diagram.

An obstacle to increasing the elongation of the striking element and, consequently, the armor penetration of Russian projectiles is the automatic loader device, first implemented in 1964 in the Soviet T-64 tank and repeated in all subsequent models. domestic tanks, which provides for the horizontal arrangement of projectiles in the conveyor, the diameter of which cannot exceed the internal width of the hull, equal to two meters. Taking into account the case diameter of Russian shells, their length is limited to 740 mm, which is 182 mm less than the length of American shells.

In order to achieve parity with the cannon weapons of a potential enemy for our tank building, the priority for the future is the transition to unitary shots, located vertically in an automatic loader, the shells of which have a length of at least 924 mm.

Other ways to increase the effectiveness of traditional armor-piercing projectiles without increasing the caliber of guns have practically exhausted themselves due to restrictions on the pressure in the barrel chamber developed during the combustion of a powder charge, due to the strength of weapon steel. When moving to more large caliber the size of the shots becomes comparable to the width of the tank hull, forcing the shells to be placed in the aft niche of the turret with increased dimensions and a low degree of protection. For comparison, the photo shows a shot of 140 mm caliber and a length of 1485 mm next to a mock shot of a 120 mm caliber and a length of 982 mm.

In this regard, in the United States, as part of the MRM (Mid Range Munition) program, MRM-KE active rockets with a kinetic warhead and MRM-CE with a cumulative warhead have been developed. They are loaded into the cartridge case of a standard 120-mm cannon shot with a propellant charge of gunpowder. The caliber body of the shells contains a radar homing head (GOS), a striking element (an armor-piercing rod or a shaped charge), impulse trajectory correction engines, an accelerating rocket engine and a tail unit. The weight of one projectile is 18 kg, the weight of the armor-piercing rod is 3.7 kg. The initial speed at the level of the muzzle is 1100 m/s, after the completion of the accelerating engine, it increases to 1650 m/s.

Even more impressive figures have been achieved in the framework of the creation of an anti-tank kinetic rocket CKEM (Compact Kinetic Energy Missile), whose length is 1500 mm, weight 45 kg. The rocket is launched from a transport and launch container using a powder charge, after which the rocket is accelerated by an accelerating solid-propellant engine to a speed of almost 2000 m / s (Mach 6.5) in 0.5 seconds.

The subsequent ballistic flight of the rocket is carried out under the control of the radar seeker and aerodynamic rudders with stabilization in the air using the tail unit. The minimum effective firing range is 400 meters. The kinetic energy of the damaging element - armor-piercing rod at the end of jet acceleration reaches 10 mJ.

During the tests of the MRM-KE projectiles and the CKEM rocket, the main drawback of their design was revealed - unlike sub-caliber armor-piercing projectiles with a separating leading device, the inertia flight of the striking elements of a caliber projectile and a kinetic missile is carried out assembled with a body of large cross-section and increased aerodynamic resistance, which causes a significant drop in speed on the trajectory and a decrease in the effective firing range. In addition, the radar seeker, impulse correction engines and aerodynamic rudders have a low weight perfection, which makes it necessary to reduce the weight of the armor-piercing rod, which negatively affects its penetration.

The way out of this situation is seen in the transition to the separation in flight of the caliber body of the projectile / rocket and the armor-piercing rod after the completion of the rocket engine, by analogy with the separation of the leading device and the armor-piercing rod, which are part of the sub-caliber projectiles, after their departure from the barrel. Separation can be carried out with the help of an expelling powder charge, which is triggered at the end of the accelerating section of the flight. Reduced-sized seeker should be located directly in the ballistic tip of the rod, while the flight vector control must be implemented on new principles.

A similar technical problem was solved as part of the BLAM (Barrel Launched Adaptive Munition) project to create small-caliber guided artillery shells, performed at the Adaptive Aerostructures Laboratory AAL (Adaptive Aerostructures Laboratory) of Auburn University by order of the US Air Force. The aim of the project was to create a compact homing system that combines a target detector, a controlled aerodynamic surface and its drive in one volume.

The developers decided to change the direction of flight by deflecting the projectile tip at a small angle. At supersonic speed, a fraction of a degree deflection is enough to create a force capable of implementing a control action. A simple technical solution was proposed - the ballistic tip of the projectile rests on a spherical surface, which plays the role of a ball bearing, several piezoceramic rods are used to drive the tip, arranged in a circle at an angle to the longitudinal axis. Changing their length depending on the applied voltage, the rods deflect the tip of the projectile to the desired angle and with the desired frequency.

The calculations determined the strength requirements for the control system:
- accelerating acceleration up to 20,000 g;
- acceleration on the trajectory up to 5,000 g;
- projectile speed up to 5000 m / s;
— tip deflection angle up to 0.12 degrees;
— drive actuation frequency up to 200 Hz;
- drive power 0.028 watts.

Recent advances in the miniaturization of infrared radiation sensors, laser accelerometers, computing processors and lithium-ion power supplies resistant to high accelerations (such as electronic devices for guided missiles - American and Russian), make it possible in the period up to 2020 to create and adopt kinetic projectiles and missiles with an initial flight speed of more than two kilometers per second, which will significantly increase the effectiveness of anti-tank munitions, and also make it possible to abandon the use of uranium as part of their striking elements.