Armor-piercing projectile calibers. What is the difference between a sub-caliber projectile and a conventional armor-piercing projectile. Modern armor-piercing ammunition

The term " sub-caliber projectile» most commonly used in tank troops. 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 shells. Let's talk about what a subcaliber is and what are its key features and principle of operation.

basic information

Key difference sub-caliber shells from conventional armored ones in that the diameter of the core, that is, the main part, is less 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 the high degree of pyrophoricity of depleted uranium, numerous fires occur, 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 breaking through the armor, such ammunition provides destructive action both equipment and manpower. Currently, the most common shells for cannons with a caliber of 115, 120, 125 mm, as well as artillery pieces 90, 100 and 105 mm. In general, this is all the information on this topic.

MOSCOW, July 23 - RIA Novosti, Andrey Kots. If modern tank fired with an armor-piercing "blank" of the times of the Second World War, then, most likely, only a dent will remain at the site of the hit - penetrating through is practically impossible. The "puff" used today composite armor confidently holds such a blow. But it can still be pierced with an "awl". Or "crowbar", as the tankers themselves call armor-piercing feathered sub-caliber shells (BOPS). About how these munitions work - in the material of RIA Novosti.

Awl instead of a sledgehammer

From the name it is clear that the sub-caliber ammunition is a projectile with a caliber noticeably smaller than the caliber of the gun. Structurally, this is a "coil" with a diameter equal to the diameter of the barrel, in the center of which is the same tungsten or uranium "scrap" that hits the enemy's armor. When leaving the bore, the coil, which provided the core with sufficient kinetic energy and accelerated it to the desired speed, is divided into parts under the action of oncoming air flows, and a thin and strong feathered pin flies at the target. In a collision due to the smaller resistivity it penetrates armor much more effectively than a thick monolithic blank.

The armored impact of such a "scrap" is colossal. Due to the relatively small mass - 3.5-4 kilograms - the core of the sub-caliber projectile immediately after the shot accelerates to a significant speed - about 1500 meters per second. When hitting the armor plate, it punches a small hole. The kinetic energy of the projectile is partly used to destroy armor, and partly converted into heat. Red-hot fragments of the core and armor go into the armored space and spread like a fan, hitting the crew and internal mechanisms of the vehicle. This creates multiple fires.

An accurate hit of the BOPS can disable important components and assemblies, destroy or seriously injure crew members, jam the turret, break through fuel tanks, undermine the ammunition rack, destroy the undercarriage. Structurally, modern sabots are very different. Projectile bodies can be both monolithic and composite - a core or several cores in a shell, as well as longitudinally and transversely multilayered, with various types plumage.

Leading devices (those same "coils") have different aerodynamics, they are made of steel, light alloys, and composite materials - for example, carbon composites or aramid composites. Ballistic tips and dampers can be installed in the head parts of the BOPS. In a word, for every taste - for any gun, under certain conditions tank battle and a specific goal. The main advantages of such ammunition are high armor penetration, high flight speed, low sensitivity to dynamic protection, low vulnerability to active protection systems, which simply do not have time to react to a fast and inconspicuous "arrow".

"Mango" and "Lead"

For 125 mm smoothbore guns domestic tanks also in Soviet time developed a wide range of feathered "armor-piercing". They were engaged after the appearance of the potential enemy tanks M1 Abrams and Leopard-2. The army, like air, needed shells capable of hitting new types of reinforced armor and overcoming dynamic protection.

One of the most common BOPS in the arsenal of Russian T-72, T-80 and T-90 tanks is the ZBM-44 "Mango" high-power projectile, which was put into service in 1986. Have enough ammo complex structure. A ballistic tip is installed in the head part of the swept body, under which there is an armor-piercing cap. Behind him is an armor-piercing damper, which also plays an important role in breaking through. Immediately after the damper are two tungsten alloy cores held inside by a light-alloy metal jacket. When a projectile collides with an obstacle, the shirt melts and releases cores that "bite" into the armor. In the tail of the projectile there is a stabilizer in the form of a plumage with five blades, at the base of the stabilizer there is a tracer. This "scrap" weighs only about five kilograms, but is capable of penetrating almost half a meter of tank armor at a distance of up to two kilometers.

The newer ZBM-48 "Lead" was put into service in 1991. Standard Russian tank autoloaders are limited by the length of the projectiles, so Lead is the most massive domestic tank ammunition of this class. The length of the active part of the projectile is 63.5 centimeters. The core is made of a uranium alloy, it has a high elongation, which increases penetration, and also reduces the impact of dynamic protection. After all, what more length projectile, the smaller part of it interacts with passive and active obstacles at a certain point in time. Sub-caliber stabilizers improve the accuracy of the projectile, and a new composite "coil" drive device is also used. BOPS "Lead" is the most powerful serial projectile for 125-mm tank guns, capable of competing with leading Western models. The average armor penetration on a homogeneous steel plate from two kilometers is 650 millimeters.

This is not the only such development of the domestic defense industry - the media reported that specifically for the latest T-14 "Armata" tank, BOPS "Vacuum-1" with a length of 900 millimeters were created and tested. Their armor penetration came close to a meter.

It is worth noting that probable adversary also does not stand still. Back in 2016, Orbital ATK launched a full-scale production of an advanced armor-piercing feathered sub-caliber projectile with a fifth-generation M829A4 tracer for the M1 tank. According to the developers, the ammunition penetrates 770 millimeters of armor.

) 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 HEAT rounds, 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 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 - 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 lead 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.

armor penetration kinetic projectiles and missiles is defined as the thickness of a homogeneous steel plate, installed perpendicular to the flight axis of the striking element, 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 Russian and American sub-caliber shells of the latest generation, equipped with armor-piercing cores from a uranium alloy, 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 M829A3 projectile rod. 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 of domestic tanks, which provides for a horizontal arrangement of projectiles in a conveyor, the diameter of which is not may 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, within the framework of the MRM (Mid Range Munition) program, active missiles MRM-KE with kinetic warhead and MRM-CE with HEAT warhead. 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-size 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 sensors, laser accelerometers, computing processors and lithium-ion power supplies resistant to high accelerations (such as electronic devices for guided projectiles - 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.

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 less 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 these are heavy tanks and fortified buildings.

Armor-piercing sub-caliber projectile and its description

The action of a sub-caliber projectile

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. The key feature of such 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. To eliminate the 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 a flat flight path 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.

Projectiles are called sub-caliber projectiles, the caliber of which is less than the caliber of the gun barrel. The idea of sub-caliber shells arose a long time ago; the main goal is to obtain the highest possible initial speed, and hence the maximum range of the projectile. Sub-caliber projectiles are designed so that specially designed light medium-caliber projectiles can be ejected from larger-caliber guns.
The projectile is supplied with a pallet, the diameter of which corresponds to the diameter of the gun. The weight of the projectile together with the pallet is much less than the regular one.
The powder charge is the same as for a regular shot of a given caliber gun. The design of a sub-caliber projectile makes it possible to obtain a significantly higher initial velocity of 1,500 - 1,800 m / s without resorting to constructive changes tools. Under the action of centrifugal force and due to air resistance, the pallet, after leaving the bore, is separated from the projectile, which travels a much greater distance than a conventional (caliber) projectile of this gun. Significant initial speed in this case It is used to destroy such a strong barrier as the armor of a tank, when a durable projectile with high manpower (velocity at the moment of impact on the armor) is required.
The property of sub-caliber shells - a high initial speed - was used in anti-tank artillery.

Rice. 1 3.7 cm armor-piercing tracer mod. 40 (3.7 cm Pzgr. 40)

1 - core; 2 - pallet; 3 - plastic tip; 4 - ballistic tip; 5 - tracer.

Rice. 2. 75-mm armor-piercing tracer mod. 41 (75/55cm Pzgr. 41)

1 - pallet; 2 - core; 3 - screw head;
4 - ballistic tip; 5 - tracer.

Sub-caliber armor-piercing shells There are two types: arr. 40 (Fig. 1) and arr. 41 (Fig. 2). The former apply to conventional 3.7 cm and 5 cm, anti-tank guns, the second - to guns with conical bores - i.e., to a 28 / 20-mm heavy anti-tank rifle mod. 41, and to 75/55 mm anti-tank gun PAK-41. There are shells 7.5 cm Pzgr.41(HK) with tungsten carbide core and 7.5 cm Pzgr.41 (StK) with steel core 7.5 cm Pzgr.41(W) coreless blank. In addition to armor-piercing sabots, high-explosive fragmentation sabots were also produced.
The device shells Pzgr. 40 Pzgr. 41 looks like. The projectile consists of a core -
1, a pallet - 2, a plastic ballistic tip - 3, a metal cap - 4 and a tracer - 5. In sabot armor-piercing shells there is no fuse, explosive charge and copper leading belt.
The core of the projectile is made of an alloy of high hardness and brittleness.
The pallet is made of mild steel.
The ballistic tip, which gives the projectile a streamlined shape, is made of plastic and covered with a metal cap made of an alloy of magnesium and aluminum.

The main difference between shells arr. 40 from shells mod. 41 lies in the design of the pallet. Pallets of shells arr. 40 (Fig. 1) to conventional anti-tank guns (3.7 cm and 5.0 cm with cylindrical barrels) consist of a body with 2 centering annular protrusions. The upper ledge plays the role of a leading belt, the lower one is a centering thickening.

7.5cm Pzgr.41

2.8cm sPzB-41

3.7cm Pzgr. 40

When the projectile is fired and moves along the channel near the barrel, the upper ledge of the pallet, which has a diameter slightly larger than the diameter of the gun, cuts along the fields, crashing into the rifling of the gun, gives the projectile a rotational
motion. The lower protrusion of the pallet, which has a diameter of the bore, centers the projectile in the bore, i.e., prevents it from skewing.
Pallets of shells arr. 41 (see fig. 2) to systems with tapered bores consist of a body with 2 tapered centering annular lugs. The diameters of the protrusions are equal to the larger diameter
barrel channel (near the breech). The cylindrical part of the pallet is equal to the smaller diameter of the bore (near the muzzle). When the projectile moves along the tapered barrel, both protrusions are compressed and cut into the rifling, while providing rotary motion projectile in flight.

Weight of projectiles mod. 40 and arr. 41 is significantly less than the weight of conventional armor-piercing shells of the corresponding calibers. Combat (powder) charge is used the same as for conventional shells. As a result, shells arr. 40 and 41 have significantly larger initial speeds than conventional armor-piercing shells. This provides an increase in armor-piercing action. However, the ballistically unfavorable shape of the projectile contributes to a rapid loss of speed in flight, and therefore the firing of such projectiles at distances exceeding 400-500 m is not very effective.
The effect of projectiles on an obstacle (armor) is the same for both types.
When a projectile hits an obstacle, the ballistic tip and pallet are destroyed,
and the core, having high speed, in general, pierces armor. Having met the second obstacle in the tank - the opposite wall, the core, which already has a low speed, due to
of its fragility, it breaks into pieces and hits the tank crew with its fragments and fragments from the tank's armor. The armor-piercing ability of these shells is much higher than conventional armor-piercing shells and is characterized by the data given in the table.

7.5 cm Pzgr.41W and7.5 cm Pzgr.41 (StK):