Purpose of the powder charge. Purpose, composition and action of auxiliary charge elements. Purpose and design of sleeves. Ammunition handling
Capsule serves to ignite powder charge.
Sleeve serves to connect all elements of the cartridge, protect the powder charge from external influences and seal the powder gases.
Based on their purpose, cartridges are divided into combat and auxiliary.
Live ammunition intended to destroy manpower or various types enemy military equipment, and depending on the type of weapon in which they are used, they are divided into small-caliber cartridges (up to 5.6 mm), normal caliber (up to 9 mm) and large caliber(over 9 mm). Basic data of domestic cartridges small arms are given in the table.
Basic data on live ammunition.
*The denominator shows values for light machine guns.
Auxiliary cartridges serve to solve problems not directly related to the destruction of manpower and military equipment. These include: small-caliber cartridges– for training and sports shooting; blank cartridges - to simulate shots at tactical exercises and field studies; educational - for teaching loading and firing techniques.
Blank cartridges contain no bullet. In training ones, there is no powder charge, and the primers must be pre-ignited (they must have deep dents from the impact of the firing pin). Along the case body of the training cartridge there are four symmetrically located grooves.
The design of small arms cartridges is identical, and their main difference lies in the design of the bullets. Live ammunition bullets are divided into ordinary and special.
Ordinary bullets (Fig. 49.a, b, c) are designed to hit an open target or manpower and unarmored vehicles located behind light cover.
Special bullets (Fig. 49.d,e) have a special effect and are intended mainly for firing at enemy military equipment and for adjusting fire.
Samples of bullets for 7.62 mm caliber cartridges model 1908.
from left to right: a – with a steel core; b – light; c – heavy;
g – tracer; d - armor-piercing incendiary ..
1 – shell; 2 - lead jacket; 3 – core; 4 – glass; 5 – tracer composition; 6 – incendiary composition.
4.2. CARTRIDGES WITH CONVENTIONAL BULLETS
To reliably hit targets, the bullet must have sufficient lethal, penetrating or special action at all ranges characteristic of this type of weapon.
The choice of the outer shape of most bullets is mainly dependent on the task of reducing air resistance. Theoretical research and practical experience show that the bullet should be oblong (length several times greater cross section), cylindrical in shape, with a pointed head and a beveled tail in the form of a truncated cone.
Depending on the speed of the bullet, its most advantageous shape should be different. In Fig. 50, the lines show the main trends in the change in the shape of a bullet with increasing speed.
As flight speed increases, the relative length of the bullet (expressed in calibers) should increase (see solid line). In this case, the length of the pointed head part should increase especially sharply (see between the solid and dash-dotted lines). With increasing speed, it is necessary, in turn, to reduce the length of the cylindrical and tail parts of the bullet (see the dashed line).
The most advantageous shapes of bullets depending on their flight speed in the air
Head part the bullet, as stated above, is done taking into account its flight speed. How more speed flight of a bullet, the longer its head part should be, since this will reduce the force of air resistance.
Cylindrical (drive part) bullet gives it direction and rotational movement, and also fills the bottom and corners of the rifling of the barrel and thereby eliminates the possibility of breakthrough of powder gases. Therefore, the bullet diameter is usually 1.02-1.04 weapon calibers. Thus, the diameter of a bullet for a weapon of 7.62 mm caliber is 7.92 mm, for a weapon of 6.45 caliber – 5.60 mm. Most types of bullets have an annular groove (knurling) on the leading part for attaching them to the cartridge cases.
Tail section Most bullets have the shape of a truncated cone, which reduces the area of discharged space behind the flying bullet.
The thickness of the bullet shells is 0.06-0.08 bullet caliber. The material used for the shell is low-carbon steel coated with tombac. Tompak consists of an alloy of copper (about 90%) and zinc (about 10%). This composition gives good penetration of the bullet into the rifling and little wear on the barrel. The core for ordinary bullets is made of lead with the addition of antimony to increase hardness or low-carbon steel. In this case, there is a lead jacket between the shell and the core.
The sleeves are divided according to their shape into cylindrical and bottle.
Cylindrical sleeve simple in design and facilitates the design of the box magazine; used in pistol cartridges.
Bottle sleeve allows you to have a larger powder charge.
The operating conditions of the cartridge case, especially in automatic weapons, place high demands on its material. The best material for making sleeves is brass, but in order to save money, sleeves are often made of mild steel clad with tombac. Tompak protects the liner from corrosion and reduces the coefficient of friction, helping to improve liner extraction. The powder charge in small arms cartridges consists of smokeless pyroxylin powder, and in 5.45 mm combat cartridges - nitroglycerin. In pistol cartridges, the gunpowder is plate-shaped; V rifle cartridges the grains of gunpowder are tubular in shape with one channel; in large-caliber cartridges - a tubular shape with seven channels. The greater the power of the cartridge, the larger the grains and the more progressive their shape. However, the grain size must ensure complete combustion of the gunpowder during the movement of the bullet along the barrel.
All primers for small arms cartridges have a similar structure and consist of a cap, a percussion compound and a foil circle placed on top of the percussion compound.
4.3. SPECIAL PURPOSE BULLETS
Bullets special purpose have a special effect. These bullets include armor-piercing, armor-piercing incendiary, tracer, armor-piercing incendiary, and incendiary.
Tracer bullets(Fig. 49.d) are intended for target designation and fire adjustment at ranges of up to 800 m (automatic bullets) and 1000 m (rifle bullets), as well as for hitting enemy personnel. In the shell of the tracer bullet, a lead core is placed in the head part, and in the bottom there is a cup with a pressed tracer composition. During the shot, the flame from the powder charge ignites the tracer compound, which gives a bright luminous trail as the bullet flies. A feature of tracer bullets is the change in mass and movement of the bullet’s center of gravity as the tracer composition burns out. However, the flight trajectory of these bullets practically coincides with the trajectory of other bullets used for shooting - this is necessary condition their combat use.
Armor-piercing incendiary bullets(Fig. 49.e) are designed to ignite flammable substances and to destroy enemy personnel located behind light armored cover at ranges of up to 300 m (automatic bullets) and up to 500 m (rifle bullets). An armor-piercing incendiary bullet consists of a shell, a steel core, a lead jacket and an incendiary composition. When it hits the armor, the incendiary composition ignites and, getting inside, ignites flammable substances. The armor-piercing effect of bullets is ensured by the presence of a core of high strength and hardness.
Armor-piercing incendiary bullets of large-caliber cartridges are similar in design and action to the same bullets of machine gun and rifle cartridges.
Armor-piercing incendiary tracer bullets(Fig. 51) provide, in addition to the considered actions, also a tracer.
The listed bullets are designed to destroy lightly armored ground targets at ranges up to 1000 m, unarmored targets, enemy fire weapons and group targets - up to 2000 m, as well as air targets at altitudes up to 1500 m.
Incendiary bullets(Fig. 52) are designed to destroy open ground targets, ignite wooden buildings, fuel in unprotected tanks and other flammable objects.
The bullet has a striking mechanism, which consists of a primer sleeve with an igniter primer, a firing pin with a sting and a moving cap that acts as a fuse. The impact mechanism is cocked when fired, when the bullet receives significant acceleration, while the oncoming cap, by inertia, settles on the firing pin, the tip of which pierces the bottom of the cap. When meeting a target, the striker moves forward and pierces the primer, which ignites, and then the incendiary composition ignites.
All special bullets for one type of weapon must provide a good enough connection with the trajectory of the main standard bullet in order to have one sight scale for firing all types of bullets.
4.4. CARTRIDGES FOR SPECIAL WEAPONS.
Bullets to special weapons They differ from ordinary ones in their shape and weight. The length of the bullet head is made shorter, and the cylindrical part is made longer to improve stability at subsonic speeds (Fig. 50). The second essential condition is an increase in the mass of the bullet, due to the low speed and the need to maintain the lethal effect of such bullets at a sufficient level.
The first cartridge in domestic practice that met these conditions was a 7.62 mm caliber cartridge of the 1943 model with a “US” bullet, adopted for service in the late 50s for use in an assault rifle AKM, equipped with a silent and flameless shooting (PBS). The subsonic speed of his bullet provided the necessary reduction in sound level when used PBS, and the increased mass of the bullet (12.5 g) with a steel core in the head provides sufficient penetrating effect.
A cartridge with such a bullet, and with it AKM with PBS still remain in service with special forces units.
The basis for the development of new silent automatic weapons was the 9-mm special SP-5 and SP-6 cartridges with a subsonic initial bullet velocity and a fairly high stopping and lethal effect, adopted for service in the early 80s. These cartridges were created on the same principle as the " US"; leaving the same shape, length and capsule of the cartridge, the designers changed the barrel of the cartridge case - for attaching a 9-mm bullet, weighing about 16 g, and the powder charge - for communicating with the bullet initial speed 270-280 m/s.
Cartridge bullet JV-5 (Fig. 53) with a bimetallic shell and a steel core; the cavity behind it is filled with lead. The shape of the bullet, 36 mm long, provides it with good ballistic properties when flying at subsonic speeds.
Special cartridge SP-6
A – steel core; B – lead jacket;
B – bimetallic shell.
1 – bullet; 2 – sleeve; 3 – powder charge; 4 – igniter primer
In terms of ballistics, both cartridges are close to each other, therefore they can be used in weapons with the same sights. The accuracy of bullets from SP-5 cartridges is slightly better than that of semi-jacketed bullets from SP-6 cartridges. The design and characteristics of bullets determine the purpose of the cartridges: for sniper shooting SP-5 cartridges are used for uncovered manpower; SP-6 cartridges are used to hit targets wearing personal protective equipment, or located in cars or behind other light shelters.
These special cartridges are produced at the Klimovsk enterprise in small batches, and their cost is high. The Tula Cartridge Plant has launched the production of PAB-9 cartridges, an analogue of SP-6, with a bullet with a hardened steel core, but cheaper. Its penetrating effect (like that of SP-6) ensures the destruction of manpower in class 3 body armor. At a distance of 100 m, it pierces a steel sheet 8 mm thick.
Main characteristics of special cartridges.
Shooting with a reduced shot sound level is ensured not only by the use of silent and flameless shooting devices, which are installed on the barrel of a weapon and inevitably increase its weight and dimensions, making it difficult to carry. IN Lately Another means is used to achieve the same result - special silent cartridges. Double-barreled small-sized special pistols chambered for such cartridges were adopted. SME and S-4M, as well as a shooting scout knife LDC.
When fired, a special cartridge PZA-M(Fig. 55.a) imparts speed to the bullet not by the force of pressure of the powder gases directly on its bottom, but through the action of a piston placed between the bullet and the powder charge. Powder gases press on the piston, which presses on the bullet, pushes it out of the cartridge case, and pushes it along the barrel.
a – PZAM b – SP-4
Special cartridges
The piston itself does not come out of the cartridge case, but locks it in the barrel, thus cutting off powder gases from entering the barrel. As a result, the shot is accompanied only by the sound of the impact of the moving parts of the weapon and the cartridge.
7.62 mm cartridge SP-4(Fig. 55.b) has a slightly different design. The cylindrical bullet is placed in a steel sleeve, without protruding beyond its front cut. Behind the bullet there is a pan, then a powder charge. When firing, the same operation occurs, except that the pan does not protrude beyond the cartridge case. This made it possible to develop a self-loading silent pistol chambered for such a cartridge. PSS, the automation of which works in the same way as that of PM. After the cartridge case is ejected from the weapon, the pressure in it drops gradually, since the pan does not adhere to the cartridge case hermetically.
The case of this cartridge is steel, clad with tombac, and has a length of 41 mm, which exceeds the length of conventional pistol cartridges. The bullet is also steel, unjacketed, in the shape of a cylinder without a pointed head and narrowing of the bottom parts. This bullet shape provides sufficient stopping power.
In addition to the pistol, a reconnaissance knife firing device has been developed and adopted for use under the SP-4 cartridge. NRS-2.
4.5. HAND FRAGRATION GRENADES
A grenade is an ammunition designed to destroy enemy personnel located openly, in trenches, trenches, and buildings at close ranges. The damage is caused by fragments or a shock wave. Grenades can be equipped with remote fuses ( RGD-5, F-1) and impact action ( RGN, RGO).
Depending on the range of fragmentation, hand fragmentation grenades are divided into offensive and defensive.
Hand grenades RGD-5 and RGN are offensive, since their throwing range is 40–50 m, and the radius of the lethal effect of fragments is no more than 25 m.
Hand grenades F-1 and Russian Geographical Society– defensive, with a throwing range of 35–45 m, the radius of the lethal effect of fragments reaches 200 m.
Main characteristics of hand fragmentation grenades.
Each hand fragmentation grenade consists of a body, a bursting charge and a fuse.
Frame serves to place a bursting charge, a fuse tube, and also to form fragments when a grenade explodes. It may have longitudinal and transverse notches along which the grenade usually breaks into fragments.
Ignition tube serves to place the fuse and seal the explosive charge in the housing; When storing, transporting and carrying grenades, the hole in the housing for the fuse is closed with a plastic plug.
Bursting charge fills the body and serves to break the grenade into fragments.
General view and manual device fragmentation grenade F1
1 – body; 2 – bursting charge; 3 – fuse
Fuse designed to explode a bursting charge.
Fuse UZRGM (Fig.57) consists of impact mechanism and actually sunk.
Impact mechanism serves to ignite the igniter primer. It consists of a striking mechanism tube in which a firing pin with a mainspring is placed. The firing pin is held in the cocked position by the trigger lever. The trigger lever is held on the hammer tube by a safety pin. It has a ring for pulling it out.
General view and design of the fuse for RGD-5, F-1 grenades
A - general form; b – in section
1 – impact mechanism tube; 2 – connecting sleeve; 3 – guide washer; 4 – mainspring; 5 – drummer; 6 – striker washer; 7 – release lever; 8 – safety pin; 9 – retarder bushing; 10 – moderator;
11 – igniter primer; 12 – detonator capsule
The fuse itself serves to explode the explosive charge of the grenade. It consists of a bushing with a retarder, an igniter primer and a detonator primer. The retarder transmits a beam of fire from the igniter primer to the detonator primer. It consists of a pressed low-gas composition.
A combat charge is an element of a shot designed to impart a given initial velocity to a projectile at the maximum permissible pressure of powder gases.
The combat charge consists of a shell, a powder charge, an ignition agent and additional elements.
The shell is designed to accommodate the remaining elements of the warhead. It is made in the form of a sleeve or a fabric cap.
The powder charge is the main part of the warhead and serves as a source of chemical energy, which, when fired, is converted into mechanical energy - the kinetic energy of the projectile.
The ignition means activates the warhead.
Additional elements include an igniter, a phlegmatizer, a decoupler, a flame arrester, a sealing device, and a fixing device.
The following basic requirements are imposed on combat charges: uniformity of action when firing, low negative impact on the surface of the barrel, durability during long-term storage, ease of preparing the charge for firing.
§ 8.1. Powder charges
The powder charge consists of one or more grades of smokeless powder. In the second case, the charge is called combined.
A powder charge can be made in the form of one or several parts (portions) and, depending on this, will be called a constant or variable charge. The alternating charge consists of a main package and additional beams. Before firing, additional beams can be removed by changing the mass of the charge and the initial velocity of the projectile. The powder charge of cartridge-loading shots (Fig. 8.1) is, as a rule, constant, simple or combined. Depending on the mass of the powder charge, it can be full, reduced or special. Typically, small and medium caliber guns use granulated pyroxylin powder, which is placed loosely in a cartridge case or in a cap.
To ensure reliable ignition in long charges, bundles of tubular pyroxylin powder or rod igniters are used. A powder charge of tubular powder is placed in a cartridge case in the form of a package tied with threads and separate tubes. Powder charges of separate cartridge-loading shots (Fig. 8.2) are, as a rule, variable and usually consist of two grades of gunpowder. In this case, granular or tubular pyroxylin gunpowder, as well as ballistic nitroglycerin gunpowder, can be used. Grain powders are placed in caps, tubular ones - in the form of bundles.
The main package is usually made from thinner gunpowder,<
to ensure, at the smallest charge, the specified speed and pressure necessary for reliable arming of the fuse. Powder charges of shots of separate cap loading (Fig. 4.3) are always variable and consist of one or two grades of gunpowder. “In this case, both granular or tubular pyroxylin powders and tubular ballista powders can be used.
Mortar warheads provide relatively low initial mine velocities and maximum pressure in the channel
mortar barrel. A complete variable mortar combat charge (Fig. 8.3) consists of an ignition (main) charge, which is located in a paper sleeve with a metal base, and several balanced additional ring-shaped beams in caps. The ignition charge contains a relatively small sample of nitroglycerin powder. Its weight usually does not exceed 10% of the weight of the full alternating charge. For mortar charges, fast-burning high-calorie nitroglycerin powder is usually used. This is due to the need to ensure their complete combustion in a relatively short mortar barrel at low loading densities. The caps of additional bundles are made of calico, cambric or silk. marking is applied.
The igniter enhances the thermal impulse of the igniter and ensures rapid and simultaneous ignition of the powder charge elements. It is a sample of black powder placed in a cap or a tube with holes (Fig. 8.4). The mass of the igniter is 0.5-5% of the mass of the powder charge.
The igniter is located at the bottom of the powder charge, and if the charge is long and consists of two half-charges, then at the bottom of each half-charge. The black powder of the igniter burns quickly, creating a
The copper reducer prevents copper plating of the gun barrel (Fig. 8.5). To make copper reducers, lead wire is used, which is located on top of the powder charge in the form of a coil with a mass equal to about 1% of the charge mass.
The action of the copper reducer when fired is that at a high temperature of the gases in the barrel bore, lead and copper form a low-melting alloy. The bulk of this alloy is removed when fired by a stream of powder gases.
The flame arrester (Fig. 8.6) is intended to eliminate the muzzle flame that is formed during a shot and unmasks the firing gun in the dark. Potassium sulfate K2SO4 or potassium chloride KS1 is used as flame-extinguishing substances, placed on top of the powder charge in a flat ring-shaped cap (1-40% of the charge mass). When fired, it lowers the temperature of the powder gases, reduces their activity and forms a dust-like shell, which prevents the rapid mixing of powder gases with air.
To eliminate the backfire, flame-extinguishing powders are used, containing up to 50% of the flame-extinguishing agent and located in the cap at the bottom of the powder charge.
The phlegmatizer is used in warheads for guns with an initial projectile speed of 800 m/s or more, in order to protect the barrels from fire and increase their survivability (two to five times). In some cases, the phlegmatizer is used to extinguish the backfire.
The phlegmatizer is an alloy of high-molecular hydrocarbons (paraffin, ceresin, petrolatum) applied to thin paper located around the warhead in its upper part. In charges made from cold powders, the mass of the phlegmatizer is 2-3%, and in charges made from pyroxylin powders - 3-5% of the mass of the charge.
The action of the phlegmatizer is that "when fired, it sublimes, enters into endothermic reactions with gases, resulting in the formation of a thin layer of gases with a low temperature at the surface of the barrel bore at the beginning of the rifled part. This reduces the heat flow from the gases to the walls of the barrel and , therefore, its height.
For guns of older models, seals were used in shots of separate cartridge loading, serving the same purpose as phlegmatizers. The seal is a cardboard case with a special lubricant.
The sealing device in combat charges of separate cartridge loading consists of normal and reinforced cardboard covers, the first of which serves to reduce the breakthrough of powder gases when cutting the leading belts into the rifling, and the second to seal the charge during storage (covered with a sealing lubricant).
The fixing device in case-loading combat charges consists of cardboard circles, cylinders and other elements designed to fix the powder charge or part of it in the case.
Study the issue in the sequence indicated in the educational materials. During the study, use size and weight models of artillery rounds. Upon completion of studying the material of the question, interview 1-2 students to check the degree of mastery of the material. Draw a conclusion on the issue.
To fulfill a number of tactical, technical and operational requirements, combat charges may include auxiliary elements in addition to gunpowder. These include: igniter, decoupler, phlegmatizer, flame arrester and sealing (obturating) device. The presence of all the listed auxiliary elements in the combat charge is not necessary.
Decoupler. When firing projectiles with copper leading bands, copper plating (copper deposition on the rifling) of the barrel occurs, reducing its diametrical dimensions, which can lead to a change in the ballistics of the projectile and even swelling of the barrel. To eliminate copper plating of the barrel bore, copper reducers are used in charges. A copper stripper is a coil of wire made from lead or a lead-tin alloy. When fired, lead melts under the influence of the high temperature of the powder gases and combines with copper, forming a low-melting alloy. This alloy is mechanically carried away by the flow of powder gases and the leading belt of the projectile during the subsequent shot. The decoupler is placed, as a rule, on top of the combat charge, and in some cases it is tied in the middle of it. The weight of the copper reducer is about one percent of the powder weight.
The phlegmatizer is used mainly in shots with a full combat charge for firing from cannons and is intended to reduce wear (burnout) of the barrel bore. In shots with a reduced combat charge, the phlegmatizer is not used. The phlegmatizer is a sheet of paper coated on both sides with a layer of high molecular weight organic substances ( ceresin, paraffin, petrolatum or their alloys). According to the design, the phlegmatizer is of sheet type and corrugated. A sheet-type phlegmatizer consists of one or two sheets and is used in combat charges made of grained pyroxylin powder when firing from small and medium-caliber guns. Corrugated phlegmatizer is used in combat charges made from ballistic-type gunpowder for artillery guns with a caliber of 100 mm or more. For more effective action, the phlegmatizer is located around the top of the combat charge near the walls of the cartridge case.
The action of the phlegmatizer when fired comes down to the fact that when the combat charge burns, part of the heat is spent on sublimation of the organic substances of the phlegmatizer, and therefore the temperature of the gases in the barrel is slightly reduced. In addition, when the phlegmatizer is triggered, vapors of organic substances, which have high viscosity and low thermal conductivity, envelop the powder gases, forming a kind of protective layer that makes it difficult to transfer heat from the gases to the walls of the barrel. This made it possible to increase the survivability of medium-caliber gun barrels by approximately two times, and small-caliber guns by more than five times. However, the use of a phlegmatizer increases carbon deposits in the barrel and impairs the extraction of cartridges due to clogging of the charging chamber.
Flame arrestors. At the moment of firing, when powder gases exit the barrel bore, a flame is formed in front of the gun, reaching significant sizes. It unmasks the weapon, especially at night. Sometimes, at a high rate of fire from medium and large caliber guns, in addition to the muzzle flame, a so-called back flame is formed, which appears when the bolt is opened, from which the crew can get burns. Backfire is especially dangerous when firing from tank and self-propelled guns.
One of the reasons for the formation of a flame is the combination of hot powder gases containing CO, H 2, CH 4 and other flammable products with atmospheric oxygen.
There are two ways to eliminate the flamingness of a shot:
– reducing the temperature of powder gases by reducing the calorie content of gunpowder, which is achieved by introducing so-called cooling additives into its composition. However, this path may not always be acceptable, since it inevitably leads to a decrease in the ballistics of the warhead;
– an increase in the ignition temperature of flammable gases when mixed with atmospheric oxygen, which is ensured by the use of flameless powders or flame arresters.
Flame arrestors are a sample of flame-extinguishing salt or flame-extinguishing powder placed in a ring-shaped cap.
Potassium sulfate (K2SO4), potassium chloride (KCl) or a mixture thereof are used as flame retardant salts in powder form. The latter are used only when firing at night, since when firing during the day they produce a cloud of smoke that unmasks the weapon.
Flame-extinguishing powders are called gunpowders containing potassium salts (K2SO4, KS1) or organochlorine compounds (extinguishing agents such as X-10, X-20, D-25).
Flame extinguishing powders containing organochlorine compounds are the most effective. They do not produce smoke, act in the charge as a normal cooling additive and are used mainly to extinguish the backfire in both cartridge and separate cartridge-loading shots.
The effect of extinguishers of the X-10, X-20 and D-25 types is that organochlorine compounds located in the lower part of the charge around the igniter, upon joint combustion, form salt KS1, which is an anti-catalyst for the ignition of powder gases when they exit the barrel.
The weight of the flame arrester is 0.5-1% of the weight of gunpowder in the combat charge.
The sealing (obturating) device consists of cardboard elements of the warhead. It serves to prevent the movement of the combat charge in the cartridge case during transportation and operation of the shots, as well as to eliminate the breakthrough of powder gases until the leading belt of the projectile is completely embedded in the rifling of the barrel.
The sealing device for cartridge loading shots consists of a circle placed directly on the gunpowder, a cylinder and a seal. Depending on the design of the combat charge and the degree to which it fills the cartridge case, the sealing device may be absent, have all three elements, one seal, or a circle and a cylinder. In the case where the projectile is equipped with a tracer device, a hole is made in the circle and seal.
The sealing device in separate cartridge-loading shots consists of two cardboard covers. The bottom cover, equipped with a loop of braid, is called normal. It serves as a shutter during firing and prevents the charge beams from falling out and moving during loading. The top cover with braid is called reinforced and is intended to secure and seal the combat charge in the cartridge case. The loop and braid make it easy to remove the caps from the sleeve. For more reliable sealing of the warhead, the entire surface of the reinforced cover is filled with a layer of PP-95/5 lubricant (95% petrolatum and 5% paraffin).
GUN CASES
The cartridge case is part of an artillery shot of cartridge and separate cartridge loading and is intended to contain a combat charge, auxiliary elements for it and ignition means; protecting the combat charge from the influence of the external environment and mechanical damage during official handling; obturation of powder gases when fired; connecting a combat charge to a projectile in cartridge-loading shots
In the cartridge case for a cartridge loading shot (Fig. 75, a) the following elements are distinguished: barrel 1, slope 2, body 3, flange 4, bottom 5, point 6.
The dulce is intended to connect the cartridge case to the projectile.
The ramp is a transitional element from the muzzle to the body.
The case body is conical in shape. The diametric dimensions of the cartridge case body are slightly smaller (0.3-0.7 mm) than the charging chamber. The taper of the cartridge case and the gap make it easier to extract it after firing. The thickness of the walls of the body is variable and increases towards the bottom.
The bottom of the sleeve has an annular protrusion (flange) on the outside, and a convexity (nipple) on the inside. The flange in most gun cartridges serves to rest against the annular bore of the barrel breech seat in order to fix the position of the cartridge case in the charging chamber, as well as to grip the ejector tabs during their extraction. At the bottom of the sleeve there is a threaded socket (point) for an ignition agent.
In the casings of separately loaded shots, most artillery systems do not have a muzzle or ramp.
The action of the cartridge case when fired is associated with the occurrence of elastic and residual deformations in its material under the pressure of powder gases. At the moment of firing, under the pressure of powder gases, the muzzle, slope and part of the case body are deformed within the limits of elastic and partially plastic deformations and fit tightly to the walls of the charging chamber, eliminating the breakthrough of powder gases towards the bolt. Only a small section of the body at the flange, which has the greatest rigidity, is not adjacent to the walls of the chamber. After the pressure drops, the diametrical size of the sleeve decreases somewhat due to elastic deformations, which makes it easier to extract.
Thus, reliable sealing of powder gases with a cartridge case depends on a metal with elastic-plastic properties, the correct determination of the wall thickness and the gap between the walls of the case and the chamber of the gun.
Classification of sleeves and requirements for them.
Cases are classified by loading method, method of resting in the chamber, material and design.
By charging method they are divided into cartridge cases for cartridge and separate cartridge loading shots.
According to the method of resting in the chamber- on sleeves with an emphasis on the flange, with an emphasis on the slope and with an emphasis on a special protrusion on the body.
Flange-mounted cartridges are most common in artillery of all calibers. Cases with an emphasis on the slope are used in small-caliber shots for firing from automatic guns. They have a flange diameter equal to the diameter of the body, and allow shots to be placed more tightly in the magazine, and also eliminate the possibility of shots being unloaded during automatic chambering.
Sleeves with an emphasis on a special protrusion on the body are not widespread.
By material The cartridges are divided into metal and cartridges with a combustible body. Metal sleeves are made of brass or low-carbon steel. Brass cartridges are the most common and have the best properties both in terms of their combat use and their production. To reduce the phenomenon of spontaneous cracking of sleeves, silicon can be added to brass. However, the consumption of scarce non-ferrous metals forces the use of low-carbon steel for the manufacture of cartridges in war and peacetime.
According to their design, metal sleeves are divided into seamless and prefabricated. Seamless sleeves are one piece and are produced by drawing on presses from a single blank. Prefabricated sleeves consist of several individual parts. They can be solid-body or rolled-up.
The following basic requirements are imposed on the sleeves:
· reliability of obturation of powder gases when fired;
· ease of loading and extraction after firing;
· strength necessary to protect the cartridge case and charge from damage under conditions of official handling;
· reliability of projectile fastening in cartridge loading shots;
· multi-firing, i.e. the possibility of repeated use of the cartridge case after appropriate repair and renewal;
· stability during long-term storage.
The first two requirements are the most important, since the normal combat operation of artillery systems as a whole depends on them. Unsatisfactory obturation of powder gases during a shot leads to their breakthrough through the bolt seat, and consequently to loss of energy and possible burns to the gun crew. Delays in the extraction of cartridges reduce the rate of fire of the guns and make it completely impossible to fire from automatic guns.
Ensuring the requirement for multiple use of cartridges for shooting is of great economic importance. The best in terms of multi-firing are brass cartridges.
The requirement for cartridge case durability is aimed at preserving their combat qualities during long-term storage. To protect sleeves from corrosion, anti-corrosion coatings are used: for brass sleeves - passivation, and for steel - phosphating, brass plating, bluing, galvanizing or varnishing. The use of metal cartridges for firing from tanks and self-propelled artillery causes gas contamination and cluttering of the fighting compartment of vehicles with spent cartridges. Gas contamination is the result of the large volume of the cartridge case chamber, in which, after extraction from the charging chamber, a significant amount of powder gases remains. These disadvantages are largely eliminated by the use of cartridges with a combustible body. A number of foreign armies are developing such cartridges. A cartridge with a combustible body consists of a brass pan, to the inner surface of which a combustible body is glued.
The burning body is an integral part of the gunpowder charge of the combat charge.
The use of cartridges with a combustible body will reduce gas contamination in tanks and reduce brass consumption. In addition, the use of these cartridges significantly reduces the amount of work required to collect them on the battlefield and evacuate them to the rear.
Classification of ignition means and requirements for them.
Ignition means are the elements of the shot intended to ignite the warhead.
According to the method of actuation, ignition means are divided into impact, electric and galvanic-impact.
Impact ignition means are activated by the impact of the striker of the percussion mechanism and come in the form of primer bushings and impact tubes. The former are used in cartridge-loading shots, and the latter in separate cap-loading shots.
Electric means of ignition, operating from an electrical impulse, are used in ammunition for rocket, coastal and naval artillery.
Currently, in tank and self-propelled artillery rounds, galvanic-percussion ignition means have been used, combining electric and percussion modes of action in one sample.
The following basic requirements are imposed on ignition means: safety in handling and sufficient sensitivity to the impulse that initiates the action; sufficient ignitability to ensure proper ignition of the powder charge and the creation of the necessary ballistic conditions; monotony of action; reliable obturation when firing; stability during long-term storage.
Currently, capsule bushings KV-4, KV-2, KV-13, KV-13U, KV-5 and shock tube UT-36 are used.
The KV-4 capsule sleeve (Fig. 78) is used in shots for guns in the barrel of which the powder gas pressure does not exceed 3100 kg/cm 2 . It consists of a brass or steel body and parts of the ignition device assembled inside it: the igniter capsule 2, a clamping sleeve 3, an anvil 4 and a sealing copper cone 5, as well as adding black powder 7, two powder firecrackers 8 and safety circles of parchment 9 and brass 10.The outer side of the body has a thread for screwing the bushing into the sleeve end.
The bottom of the case is solid; three key grooves are made on its outer surface.
On the inside of the bottom of the housing there is a nipple with a slot 1 for placing parts of the ignition device. To secure powder firecrackers and mugs, the barrel of the case is rolled up. The brass circle and the sealing area are covered with mastic varnish or enamel for tightness.
Action of the capsule sleeve. When the firing pin hits the bottom of the primer sleeve, a dent is formed, which presses the igniter primer against the anvil, as a result of which the impact composition of the igniter primer is ignited. The gases formed during the combustion of the shock composition, passing through the anvil channel, lift the copper sealing cone and, flowing around it, ignite the powder firecrackers, and the latter ignite the gunpowder of the combat charge. As the pressure in the gun's charging chamber increases, the powder gases move the obturating cone in the opposite direction, pressing it against the walls of the anvil socket, which ensures obturation, i.e., eliminating the possibility of powder gases breaking through the thin part of the bottom of the bushing at the point of impact.
HANDLING AMMUNITION