Military Review

Advanced rifle ammunition

84
Currently, the leading armies of the world have begun to implement programs to develop new types of small weapons (“Warrior” in Russia and NGSAR in the USA). As more than a century of experience in the development of unitary cartridges, and then intermediate and low-impulse, shows, the most promising solution is the advanced development of new types of ammunition.


According to the results of the Second World War, it was concluded that it is necessary to improve the design of the most expendable type of ammunition (ammunition for automatic small arms) and expand the resource base for their production.

Cartridges with metal sleeves

The saturation of infantry units with automatic weapons in the defense industry caused a shortage of copper, traditionally used in cartridge brass (used for the production of cartridge cases) and tombac (used for the production of bullet shells).

The most effective solution to the problem of resource shortages was the use of mild steel, coated on both sides with copper to protect against corrosion, or without coating, used in wartime to produce so-called surrogate shells. In the post-war period, the technology of coating steel liners with a special lacquer was mastered, protecting them from moisture and reducing friction in the chamber (up to a certain temperature limit).



Despite the similarity of the technical characteristics of mild steel and copper alloys, the latter have an advantage in ductility and corrosion resistance. Lacquer coating of steel sleeves has low wear resistance and in the process of reloading when in contact with the metal parts of the weapon has the ability to be damaged and transferred to the elements of automation, disabling them. In the case of the extraction of unused cartridges from the barrel after the end of firing, their liners lose their lacquer coating due to its burning out when they come into contact with the heated surface of the chamber, after which they are rapidly oxidized and the cartridges become unsuitable for further use.

The increased consumption of ammunition by infantrymen armed with automatic weapons was the basis for increasing the wearable ammunition by reducing the weight of ammunition. Until the beginning of the 1970-ies, the main direction of reducing the weight of the wearable ammunition was first to switch to intermediate, and then to low-impulse cartridges, due to the desire to increase the accuracy of automatic fire from uncomfortable positions. After adopting the AK-74 assault rifle and the M-16 automatic rifle, this reserve for reducing the weight of wearable ammunition was exhausted - an attempt to use lighter arrow-shaped bullets revealed their increased wind drift.

Advanced rifle ammunition


At present, bullets with a steel core, a lead shirt and a tompak shell are used predominantly as striking elements. In order to increase armor penetration, the US Army switched to using M80A1 EPR and M855A1 all-metal bullets without a lead shirt consisting of a tompac shell and a core with a steel head and a tail of bismuth.

Bezgolovy ammunition

In the 1980-ies in the USSR and NATO countries, an attempt was made to radically solve the problem of the high material consumption of classical cartridges by switching to sleeveless ammunition. The greatest progress in this direction was made by the German company Heckler und Koch, which created the HK G11 automatic rifle, using the DM11 cartridgeless cartridges developed by Dynamit Nobel.



However, the military operation of the 1000 series of HK G11 rifles in the Federal Border Service of Germany showed their danger to servicemen due to the regular spontaneous combustion of caseless cartridges in the chamber, despite its structural separation from the rifle barrel. As a result, the German border guards were first banned from using automatic firing mode, and then generally removed HK G11 from service because of the senselessness of its use as a purely self-loading weapon in the presence of overly sophisticated automation (“cuckoo clock”).

Cartridges with plastic sleeves

The next attempt to reduce the material consumption of small arms ammunition and increase wearable ammunition was carried out in 2000 in the USA by AAI (currently Textron Systems, Textron Production Division) under the LSAT (Lightweight Small Arms Technologies) program, which led to the creation of a light machine gun and an automatic carbine, designed for combined ammunition with cartridges with a brass sleeve, plastic sleeve and caseless, made in a telescopic form factor.

The sleeveless cartridges were expected to spontaneously ignited in the barrel chamber, despite its detachable design, therefore the choice in the LSAT program was made in favor of cartridges with a plastic sleeve. However, the desire to reduce the cost of ammunition led to the wrong choice of type of plastic: as such was used polyamide, which has all the necessary characteristics, except for one, but the most important - its maximum operating temperature does not exceed 250 degrees Celsius.



Back in 1950-s, it was determined by the results of field tests that the barrel of a DP machine gun in the conditions of continuous firing with bursts with interruptions for changing stores heats up to the following values:

150 shots - 210 ° C
200 shots - 360 ° C
300 shots - 440 ° C
400 shots - 520 ° C

In other words, in conditions of intense combat, after the first two hundred cartridges have been used up, the barrel of the light machine gun is guaranteed to reach the melting point of the polyamide.

In connection with this circumstance, the LSAT program in 2016 was closed and the CTSAS (Cased Telescoped Small Arms Systems) program was launched on its basis in order to develop telescopic cartridges on a new material basis. Judging by the interview with the US Administrator Cory Phillips of the program, given to thefirearmblog.com online edition in March 2017, the most heat-resistant structural polymer, polyimide, whose maximum operating temperature is 400 ° C, was chosen as the material for the plastic sleeves.

Polyimide as a cartridge case material also has another valuable property — when heated above this level, it becomes charred without melting to release volatile substances that do not contaminate the barrel chamber, while the charred surface of the sleeve serves as an excellent antifriction material when it is extracted after firing. The strength of the flange of the sleeve provides a metal flange.

The temperature in 400 degrees is the permissible limit for heating the barrels of small arms, after which their distortion occurs, since the temperature of the technological tempering of barrels ranges from 415 to 430 degrees. However, the tensile strength of polyimide at a temperature of 300 and more degrees drops to 30 MPa, which corresponds to the pressure in the chamber 300 atmospheres, i.e. an order of magnitude less than the maximum pressure level of powder gases in modern models of small arms. When you try to remove the cartridge case from the chamber of the classic design, a metal flange will be torn off with a ramrod being knocked out of the barrel.

Heating of the cartridge in the classic design chamber can be controlled to a certain extent by firing from an open bolt (machine guns), but in the case of intense shooting and firing from a closed bolt (automatic rifles and automatic rifles) heating of the cartridge over 400 degrees is almost inevitable.

Cartridges with aluminum sleeves

Another alternative to copper alloys is aluminum alloys used in the cartridges of the serial pistol cartridges, in the pilot development of rifle cartridges and in serial shots to the 30-mm GAU-8A automatic cannon. Replacing copper with aluminum allows you to remove the limit on the resource base, reduce the cost of the liner, by 25 percent reduce the weight of the ammunition and, consequently, increase the wearable load.

In 1962, at TsNIITOCHMASH, experienced cartridges of caliber 7,62x39 mm with an aluminum alloy sleeve (GA code) were developed. The liner had an anti-friction graphite coating. In order to prevent electrochemical corrosion, the primer cup was made of aluminum alloy.

However, the use of such shells is prevented by their only negative property - self-ignition of aluminum and its alloys in air when heated to 430 ° C. The heat of combustion of aluminum is very high and amounts to 30,8 MJ / kg. The external surface of products is subject to self-ignition when heated to the specified temperature and the permeability of the oxide film to air oxygen increases or when heated to a lower temperature in case of damage to the oxide film. A non-plastic ceramic oxide film (thickness ~ 0,005 μm) is destroyed by the deformation of a plastic metal sleeve under the action of the pressure of powder gases, the permeability of the oxide film is achieved by heating with intense firing. The cartridges self-ignite only in air after extraction from the barrel, where a negative oxygen balance is maintained during the combustion of gunpowder.



Therefore, aluminum sleeves have been distributed only as part of pistol cartridges of 9x18 PM and 9x19 Para calibers, the intensity of firing of which and the temperature reached in the chamber does not match any of these indicators machine guns, automatic rifles and machine guns.

Aluminum was also used in an experienced cartridge 6x45 SAW Long, the sleeve of which was equipped with an elastic silicone liner, which tightens the cracks in the metal and oxide film. However, this decision led to an increase in the linear dimensions of the cartridge, the associated size of the receiver and, accordingly, the weight of the weapon.



Another solution, but brought to service, is the 30-mm artillery shot 30x173 GAU with an aluminum alloy shell. This was made possible through the use of a special low molecular weight "cold" propellant charge. The thermochemical potential of the powder is directly proportional to the combustion temperature and inversely proportional to the molecular weight of the combustion products. The classic nitrocellulose and pyroxylin powders have a molecular weight of 25 and a burning temperature of 3000-3500 K, and the molecular weight of the new powder is equal to 17 at a burning temperature of 2000-2400 К with the same impulse.



Perspective cermet sleeve

The positive experience of the use of artillery shots with an aluminum sleeve makes it possible to consider this metal as a structural material for the shells of small arms cartridges (even without a special throwing composition). In order to confirm the correctness of this choice, it is advisable to compare the characteristics of brass and aluminum alloy liners.

Brass L68 contains in its composition 68 percent copper and 32 percent zinc. Its density is 8,5 g / cm3, hardness - 150 MPa, tensile strength at 20 ° C - 400 MPa, elongation at tensile - 50 percent, coefficient of sliding friction on steel - 0,18, melting point - 938 ° C, temperature zone of brittleness - from 300 to 700 ° C.

As a replacement for brass, it is proposed to use aluminum doped with magnesium, nickel and other chemical elements in a volume fraction of no more than 3% in order to increase the elastic, thermal and foundry properties without affecting the resistance of the alloy against corrosion and cracking under load. The strength of the alloy is achieved by its reinforcement with dispersed fibers of aluminum oxide (diameter ~ 1 μm) in a volume fraction of 20%. Protection against surface self-ignition is provided by replacing the fragile oxide film with ductile copper / brass coating (thickness ~ 5 μm) applied by electrolysis.



The obtained cermet composite belongs to the class of cermets and is formed into the final product by injection molding in order to orient the reinforcing fibers along the axis of the sleeve. The anisotropy of the strength properties makes it possible to preserve the flexibility of the composite material in the radial direction to ensure tight contact of the liner walls with the surface of the chamber under the action of the pressure of powder gases in order to obturation the latter.

Antifriction and extreme pressure properties of the liner are ensured by applying a polyimide-graphite coating (thickness ~ 10 μm) on its outer surface with equal volume fractions of binder and filler that can withstand the 1 GPa contact load and the operating temperature of the ICE pistons.

The density of the cermet is 3,2 g / cm3, tensile strength in the axial direction: at 20 ° C - 1250 MPa, at 400 ° C - 410 MPa, and tensile strength in the radial direction: at 20 ° C - 210 MPa, at 400 ° C - 70 MPa, relative elongation under tension in the axial direction: at 20 ° C - 1,5%, at 400 ° C - 3%, relative elongation at tension in the radial direction: at 20 ° C - 25%, with 400 ° C - 60 % melting point - 1100 ° C.

The slip friction coefficient of the antifriction coating on steel is 0,05 with a contact load of 30 MPa and higher.

The technological process of production of cermet sleeves consists of a smaller number of operations (mixing metal with fiber, casting sleeves, hot rolling of collar and dulce, brassing, anti-friction coating) compared to the number of operations in the manufacturing process of brass sleeves (casting billets, cold drawing in six aisles, cold knurling and dulz).

The weight of the brass sleeve of the cartridge 5,56х45 mm is equal to 5 grams, the weight of the cermet sleeve is 2 gram. The cost of one gram of copper is 0,7 US cent, aluminum - 0,2 US cent, the cost of dispersed aluminum oxide fibers - 1,6 US cent, their weight in the liner does not exceed 0,4 gram.

Prospective bullet

In connection with the adoption of army bulletproof vests of class 6B45-1 and ESAPI, not punched by handgun bullets with a steel core at a distance of 10 or more meters, it is planned to switch to the use of bullets with a core of sintered alloy of tungsten carbide powders (95%) and cobalt (5%) with a specific gravity of 15 g / cc, not needing to be weighted with lead or bismuth.

The main material of the shell of bullets is tompac consisting of 90% copper and 10% zinc, the density of which is 8,8 g / cc, melting point - 950 ° C, tensile strength - 440 MPa, compressive strength - 520 MPa, hardness - 145 MPa, elongation - 3% and the coefficient of sliding friction on steel - 0,44.

Due to the increase in the initial speed of bullets to 1000 and more meters per second and an increase in the rate of fire to 2000 and more shots per minute (AH-94 and HK G-11), the tompac ceased to meet the requirements for bullet shells due to the large thermoplastic wear bore due to the high coefficient of sliding friction of the copper alloy on steel. On the other hand, artillery shells are known, in the construction of which the copper lead belts are replaced by plastic (polyester), the friction coefficient of which is at the level of 0,1. However, the operating temperature of the plastic belts does not exceed 200 ° C, which is half the maximum temperature of the trunks of small arms before they begin to warp.

Therefore, it is proposed to use a polymer composite (thickness ~ 0,5 mm) as an envelope for a promising bullet with an all-metal core, containing in equal volume fractions of the PM-69 type polyamide and colloidal graphite with a total density of 1,5 MPa, tensile strength 90 MPa compression, 230 MPa hardness, 330 MPa contact load, maximum operating temperature 350 ° C, and sliding friction coefficient on 400 steel.

The shell is formed by mixing the polyimide oligomer and graphite particles, extruding the mixture into a mold with embedded parts - the core of the bullet and temperature polymerization of the mixture. The adhesion of the shell and the core of the bullet is ensured by the penetration of the polyimide into the porous surface of the core under the action of pressure and temperature.

Perspective telescopic cartridge

Currently, the most progressive form factor of a small arms cartridge is considered to be telescopic with the placement of a bullet inside a pressed projectile charge. The use of dense checkers instead of the classic granular charge with a lower bulk density allows one and a half times to reduce the length of the cartridge and the associated envelope of the receiver of the weapon.



Due to the design features of the reloading mechanism (detachable barrel chamber) of small arms models (G11 and LSAT) using telescopic cartridges, their bullets are recessed into the thrusts of the propelling charge below the edges of the sleeve. The open end of the secondary propellant charge from dirt and moisture protects the plastic cap, which also plays the role of the front obturator when fired (by blocking the joint of the detachable chamber and the barrel after the bullet breaks through). As the practice of troop exploitation of DM11 telescopic cartridges has shown, this method of cartridge configuration, which does not ensure that the bullet stops in the bullet entrance of the barrel, leads to bullet distortions when fired and, accordingly, loss of accuracy.

To ensure the specified sequence of operation of the telescopic cartridge, its propelling charge is divided into two parts - the primary charge of relatively low density (with a higher burning rate), located directly between the capsule and the bottom of the bullet, and the secondary charge of a relatively higher density (with a lower burning rate), located concentrically around the bullet. After the capsule is pricked, the primary charge is first triggered, pushing a bullet into the barrel bore and creating a boost pressure for the secondary charge that moves the bullet in the barrel bore.

To hold the secondary charge checkers inside the cartridge, the edges of the open end of the liner are partially rolled. The bullet is held in the cartridge by pressing it into the secondary charge checker. Placing the bullet along the entire length in the dimensions of the sleeve reduces the length of the cartridge, but at the same time creates an unfilled volume of the sleeve around the ogival part of the bullet, which leads to an increase in the diameter of the cartridge.

In order to eliminate these shortcomings, a new layout of the telescopic cartridge, designed for use in small arms with a classic non-detachable barrel chamber with any type of reloading mechanism (manual, gas engine, moving barrel, semi-free bolt, etc.) and method of firing (with front or rear sear).

The proposed cartridge is equipped with a bullet that extends beyond the liner with its lively part and thereby rests against the barrel entrance of the bullet. Instead of a plastic cap, the open end of the propellant is protected by a moisture-resistant varnish that burns when fired. Some increase in the length of the proposed cartridge compared with the known telescopic cartridges is compensated by a decrease in its diameter due to the elimination of unfilled volumes inside the liner.

In general, the proposed telescopic cartridge will increase the number of cartridges in infantry infantry ammunition by a quarter, and will also reduce the consumption of materials, laboriousness and cost of production of cartridges.
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  1. Mountain shooter
    Mountain shooter 9 December 2017 15: 57 New
    +2
    How is it that everything is not just in this weapon. Self-contained ammunition goes into the distance.
    1. your1970
      your1970 10 December 2017 11: 19 New
      0
      type in the internet - a reload of Li cars. You’ll be very surprised which conveyor can be arranged for reloading (if only there were components)
      1. brn521
        brn521 11 December 2017 09: 05 New
        0
        Quote: your1970
        type in the internet - reload cars Lee

        I typed in Google. The result is zero.
        1. Bykov.
          Bykov. 21 February 2018 17: 13 New
          0
          Quote: brn521
          Quote: your1970
          type in the internet - reload cars Lee

          I typed in Google. The result is zero.

          Lee reload
      2. 4thParasinok
        4thParasinok 28 January 2018 20: 18 New
        0
        Quote: your1970
        type in the internet - a reload of Li cars. You’ll be very surprised which conveyor can be arranged for reloading
        Are you going to reload shellless or telescopic cartridge? the hero however ...
      3. aws4
        aws4 16 July 2018 18: 34 New
        0
        you probably don’t know what a conveyor is, although you probably didn’t mean the races wrote the conveyor laughing yes technology goes forward lol
  2. Krasnyiy komissar
    Krasnyiy komissar 9 December 2017 16: 09 New
    +2
    So far, the most promising are cartridges with an aluminum sleeve, because the density of aluminum is almost three times lower than that of steel, and the strength of some alloys is quite comparable to brass. Plastics are significantly inferior in strength even to pure aluminum, so their prospects are foggy.
    1. KCA
      KCA 9 December 2017 16: 55 New
      +8
      Luminium burns a hefty hot, even splits water into hydrogen and oxygen, and even in an alloy with magnesium ... Ricochet of an enemy bullet or a fragment on such a sleeve can lead to hellish consequences, it will not break through, but it will burn through the body armor and the body through and through, it would be scary to fight such cartridges, an automatic machine without nuclear war would have to be held outstretched, so that in case of which drops of molten metal would not burn the official boots
      1. zxc15682
        zxc15682 9 December 2017 17: 17 New
        +1
        It is necessary to do paper sleeves .. And everyone will be happy laughing
        1. Vadim237
          Vadim237 9 December 2017 23: 14 New
          +1
          The sleeves can be printed from tantalum carbide 3D, this material is used for the processing tool - one of the most durable, and the most heat-resistant - the melting point is 3880 degrees, and the inside of the sleeve is made of aluminum alloy.
    2. Locksmith
      Locksmith 9 December 2017 17: 23 New
      +3
      Quote: Krasnyiy komissar
      Plastics are significantly inferior in strength even to pure aluminum

      DELRIN THREE STRONGER, TEN MORE wear resistant than aluminum and some alloys. And there are a lot of such "weak" plastics. The 14 mm thick delrin gear, module 1, easily transfers a power flow of the order of 5-8 kW laughing
      1. Lopatov
        Lopatov 9 December 2017 17: 49 New
        +3
        Well, yes, plastics and composites based on them are much more promising here.
        1. prodi
          prodi 9 December 2017 18: 05 New
          0
          in addition to the temperature, the automation, pretty much, is hitting cartridges
        2. avt
          avt 9 December 2017 19: 11 New
          +1
          Quote: Spade
          Well, yes, plastics and composites based on them are much more promising here.

          request It’s clear that nothing is clear ..... For the time being, none of the above QUALITATIVE leap, so that suddenly, immediately, immediately rushed to change the Armament of the army, well, as with the advent of breech-loading weapons for this very metal matron. Everything described (not bad by the way in in the form of a review in ,, format ") for the time being searches exclusively within the framework of" cost-effectiveness "for existing calibers and sizes. They even stuck such exotic things as sleeveless ones ... far away on the shelf. Plastic ..... maybe, maybe. Actually like the same plastic stores, but again for the rifle already in service. In general, even a rifle ,, Coalition, "for the time being is not observed. Or maybe we’ll go straight to ,,, beam" hand weapons? bully
      2. Operator
        9 December 2017 18: 48 New
        +6
        At 400 degrees Celsius, the gear from any plastic will transmit zero power flow, since it will melt / lose strength even at 200-300 degrees laughing

        The plastic problem is the heat resistance of the hydrogen-carbon chemical bond, which is not removable. The metal-metal chemical bond is much stronger, the metal-ceramic fiber composite (corundum, boron, carbon) is generally beyond competition.

        Composite aluminum-corundum fiber - cheap and practical.
        1. prodi
          prodi 9 December 2017 19: 26 New
          +1
          not sure galvanizing or something like that would be more practical than painted tin
          1. Operator
            9 December 2017 20: 12 New
            +1
            Zinc is a brittle metal, brass is a ductile alloy of copper. Therefore, we are talking about brassing or copper plating (as an option) of aluminum sleeves.

            The brass coating protects the external anti-seize graphite coating of the sleeve from mechanical damage when reloading the weapon, as well as the use of a Kel-Tec RFB type feeder (eliminating contact of the sleeve with the side surface of the bolt and barrel ramp)

            1. prodi
              prodi 9 December 2017 20: 25 New
              +1
              I don’t even know which way to drive ... A galvanized bucket is fragile? But even galvanizing looks cheaper than your examples. Corrosion of the liner with broken varnish is greatly exaggerated, and the effect of this corrosion on AK battle is even greater
              1. Operator
                9 December 2017 22: 53 New
                +3
                If the zinc coating of the bucket can withstand the impact of pressure (3000 atmospheres) and temperature (2400 degrees) of powder gases with a slew rate of 0,001 seconds - then yes, it is not fragile laughing

                This is not about the corrosion of aluminum-magnesium alloy (withstanding the action of sea water), but about its resistance to self-ignition when heated to 430 degrees, when the natural oxide film begins to pass air oxygen and self-ignites.
                Plus, under the impact of pressure and the associated elastic deformation of the aluminum sleeve, the oxide film cracks in an elementary way, allowing oxygen to reach the pure metal at a much lower temperature (~ 300 degrees).

                The solution is to replace the oxide film with a plastic brass / copper coating.
                1. prodi
                  prodi 10 December 2017 07: 50 New
                  0
                  Quote: Operator
                  If the zinc coating of the bucket can withstand the impact of pressure (3000 atmospheres) and temperature (2400 degrees) of powder gases with a slew rate of 0,001 seconds - then yes, it is not fragile laughing

                  I don’t understand, are you going to reload used cartridges? winked After all, everything has been done as practical as possible: cheap, reliable and environmentally friendly. As for the telescopic ammunition, for the infantry shooting it is hardly better: the ammunition will turn out to be more voluminous, and the automation will need more accurate - it will turn out only “one more tool” that will turn away from dirt
                  1. Operator
                    10 December 2017 11: 35 New
                    +1
                    The volume of the telescopic cartridge with the open revitalizing part of the bullet is one in one volume of the classical cartridge due to the use of pressed powder instead of bulk.

                    The mechanism for reloading weapons replenished with just one element - the feeder. But the game is worth the candle - wearable ammunition will increase by a quarter.
                    1. prodi
                      prodi 10 December 2017 12: 57 New
                      0
                      the "extra" volume in the sleeve is likely to go to additional gunpowder, because something needs to be done with body armor, and a more powerful cartridge will only tighten the requirements for automation
                      1. Operator
                        10 December 2017 16: 26 New
                        0
                        In part of the volume, cartridges of the same caliber are compared.
                    2. garri-lin
                      garri-lin 11 December 2017 12: 36 New
                      0
                      The mechanism for reloading weapons replenished with just one element - the feeder. But the game is worth the candle - wearable ammunition will increase by a quarter. [/ Quote]
                      If the volume of the cartridge is the same, where does the gain in ammunition come from? The compactness of telescopic cartridges is greatly exaggerated.
                      Weight is much more important. And in this category is that classic that telescopic. The difference is minimal. Relieving the weight of a conventional cartridge will give a commensurate increase in ammunition.
                      And at all. My personal opinion of telescopes is nothing more than a fad. And soon they will be abandoned.
                      1. prodi
                        prodi 11 December 2017 18: 36 New
                        0
                        this is my version: if you apply pressed powder in a standard cartridge
                        5.45x39, then the cartridge will become more powerful. Although, in my opinion, it will nevertheless have to put a 5.45 bullet into the rifle cartridge. Weapons will become heavier, and wearable ammunition significantly less. And it will still "get off a little blood"
                      2. Operator
                        11 December 2017 20: 06 New
                        0
                        Aluminum alloy is three times lighter than brass / steel, a cartridge with an aluminum sleeve is a quarter lighter than a cartridge with a brass / steel sleeve.
        2. Lopatov
          Lopatov 10 December 2017 10: 55 New
          +1
          Quote: Operator
          At 400 degrees Celsius, the gear from any plastic will transmit zero power flow, since it will melt / lose strength even at 200-300 degrees

          And if it has a working temperature range from -60 to +700, like organosilicate materials?
          1. Operator
            10 December 2017 11: 44 New
            +2
            Organosilicate materials (silicones, silicones) do not hold the load even at 20 degrees Celsius, therefore only elastic products, paints and varnishes are made from them.

            In addition, during the thermal decomposition of silicones, silicon is released, which, when reacted with oxygen from the air, forms an oxide, which is an excellent abrasive and, as such, will destroy the surface of the barrel chamber (being used in the design of the sleeve).

            The destruction of the polyimide-graphite coating only increases the amount of carbon (soot) on the surface of the chamber, since the polyimide consists only of carbon, hydrogen, oxygen and nitrogen.
      3. Krasnyiy komissar
        Krasnyiy komissar 9 December 2017 19: 22 New
        +1
        And what is the working temperature of delrin? Most brands have a little more than a hundred degrees, and then a sharp loss of mechanical strength. No, we need more durable material. B96 aluminum alloy is much more suitable for use as a material for sleeves.
  3. tchoni
    tchoni 9 December 2017 17: 32 New
    0
    What are the difficulties, however, with a telescopic cartridge ... Could it be easier to reduce the diameter of the sleeve? Let's say from 11-12 millimeters to 9 - and in the same horn, a quarter more rounds of ammunition will fit., And if up to 7, for example for caliber 5.45 - your fly will fly away ... we get the same 30 percent. increased ammunition.
    1. 4thParasinok
      4thParasinok 28 January 2018 20: 26 New
      0
      Quote: tchoni
      It may be easier to reduce the diameter of the sleeve
      not easier, the recoil momentum and the length of the cartridge will increase, this will lead to an increase in the length of the weapon and a decrease in accuracy.
  4. san4es
    san4es 9 December 2017 17: 42 New
    +5
    The greatest progress in this direction was achieved by the German company Heckler und Koch, who created the automatic rifle HK G11, which used cartridge-free cartridges DM11


    ... And a little more
    1. Siberia 9444
      Siberia 9444 9 December 2017 20: 25 New
      +1
      The return is strong, DTK is not. But if you shoot three bullets at once, then the shooter takes aim for a long time negative
      1. san4es
        san4es 9 December 2017 20: 34 New
        +4
        Quote: Siberia 9444
        Strong recoil negative

        ... Yes, and a lot of smoke ... even hang an ax ... B.k. (I think) - afraid of moisture ...
        Therefore (everything) and did not go request
      2. Operator
        9 December 2017 23: 08 New
        +2
        G11 shoots in bursts of a fixed length of three shots, due to the carriage automation scheme, their recoil momentum is added up and exceeds the SVD recoil momentum by 20 percent.
        1. Aqela
          Aqela 10 January 2018 20: 08 New
          0
          Quote: Operator
          G11 shoots in bursts of a fixed length of three shots, due to the carriage automation scheme, their recoil momentum is added up and exceeds the SVD recoil momentum by 20 percent.

          So yes, it is clearly visible that the return is not weak ... what
      3. ProkletyiPirat
        ProkletyiPirat 9 December 2017 23: 32 New
        0
        Quote: Siberia 9444
        The return is strong, DTK is not.

        Firstly, this system allows DTK
        Secondly, it’s the return of three shots ...
  5. san4es
    san4es 9 December 2017 17: 54 New
    +2
    Automation work with cartridgeless cartridges (cartridges)
  6. Monarchist
    Monarchist 9 December 2017 19: 16 New
    0
    Quote: zxc15682
    It is necessary to do paper sleeves .. And everyone will be happy laughing

    Jokes as jokes, and yet, for dl, hunting rifles made such cartridges
    1. garri-lin
      garri-lin 9 December 2017 19: 53 New
      +1
      The article lacks the signature "to be continued" I liked it very much, but there are many understatements. For example, little has been said about bullets.
      1. Romario_Argo
        Romario_Argo 10 December 2017 12: 19 New
        0
        E = m * v / 2
        bullet weight 5 gram x 1000 m / s = 5000 / 2 = 2500 kgf / 10 = 250 MPa
        - This is a point blank shot.
        for example, a bullet for SVD B-32 10 gram x1000 m / s / 2 = 5000 kgf / 10 = 500 MPa
        "Ratnik-2" has ceramic armor plates with a thickness of 20 mm = 2000 MPa
        new protection class Br 6
        1. CRP
          CRP 11 December 2017 10: 28 New
          +3
          Quote: Romario_Argo
          E = m * v / 2
          bullet weight 5 gram x 1000 m / s = 5000 / 2 = 2500 kgf / 10 = 250 MPa


          It hurts you have simplified, the original formula with a square of speed.
          E = m * v * v / 2,
          1. CTABEP
            CTABEP 12 December 2017 18: 42 New
            +1
            Yes, generally tin, measure the energy of a bullet in Pascals laughing
            1. Aqela
              Aqela 10 January 2018 20: 11 New
              0
              laughing well, that is not in volt-amperes! laughing good
    2. parkello
      parkello 10 December 2017 11: 46 New
      +2
      and not just for hunting weapons. for example, on revolvers, too, signal pistols, too ... thick paper and covered with some kind of muck, Schaub was not damp. but they get damp ..di and the pallet of the sleeve still had to be made of metal. therefore, on such a type of weapon as a revolver or a pump-action carbine, a double-barreled shotgun or a signal pistol, they can use folder cartridges. but for a machine gun or assault rifle they are not suitable.
  7. crambol
    crambol 9 December 2017 21: 22 New
    0
    In campaigns in the Caucasus on the Klukhor pass I found German duralumin cartridges from cartridges for rocket launchers.
  8. groks
    groks 9 December 2017 21: 32 New
    0
    I did not understand about the self-ignition of aluminum at 430C. Then it could not be melted in the air.
    It is possible to solve some problems of sleeveless, if you make a bullet-sleeve. But there will be their own hassles - the cartridge will be long, the caliber will be large, and the density of the bullet is small, only a ramrod when misfired.
    1. Operator
      9 December 2017 23: 35 New
      +1
      During casting, aluminum at the first moment is exactly what burns in the surface layer of air, absorbing oxygen from it and thereby terminating the combustion process. To save metal, a nitrogen atmosphere is used during casting.

      The auto-ignition temperature in the air of droplets, powder or aluminum chips is even lower - 270 degrees. Small particles, tanned from the surface, self-heat up to 430 or more degrees, the surface layer of air without oxygen is not formed due to the small size of the particles.
      1. groks
        groks 10 December 2017 09: 14 New
        +1
        Nothing burns. Leo in the air for a year now. And so that the metal does not stick, we use just the powder - it also does not burn.
        1. Operator
          10 December 2017 11: 50 New
          0
          It is not the surface of the liquid metal that burns, but its vaporization in the vapor phase above the surface of the metal (until oxygen burns out in the surface air layer). The powder on the inner surface of the injection mold does not burn, since it is completely filled with metal.

          There are technical standards on the temperature limit of self-ignition of various materials when they are heated in air (taking into account the fractional nature of the materials). For aluminum powder, the declared temperature is 250-300 degrees Celsius.
          1. groks
            groks 10 December 2017 12: 16 New
            0
            If you take a tablespoon, fill with powder, put on the surface of molten aluminum, then the powder does not burn. Thrown into a crucible from a spoon also does not burn. It’s just that sometimes for casters, I’m doing something on trifles, so I’ve seen enough and tried it. Poured onto the fire - it burns, every Soviet boy conducted this experiment.
            1. Operator
              10 December 2017 16: 30 New
              +1
              What is it about - molten aluminum creates an air cushion with burnt oxygen above its surface, which, incl. protects aluminum powder from fire.
              1. groks
                groks 10 December 2017 16: 59 New
                0
                Well, when did I scoop it with a bucket and drag it into a mold? Also, it doesn’t burn.
                1. Operator
                  10 December 2017 17: 33 New
                  0
                  Molten aluminum always flies, even when in the bucket.
                  1. groks
                    groks 10 December 2017 18: 51 New
                    0
                    The air above it changes quite quickly. Like the crucible. If the melt splashes out, then it also does not light up.
                    1. Operator
                      10 December 2017 21: 00 New
                      0
                      When slag is removed after electric smelting of aluminum from alumina, individual aluminum droplets adhering to the slag burn with a bright flame.

                      In any case, I am guided by the technical standards for self-ignition of solid aluminum of various fractions and the experience of manufacturers of aluminum cartridges.
                      1. groks
                        groks 10 December 2017 21: 06 New
                        +1
                        And I only own experience. Can manufacturers still have an alloy?
  9. family tree
    family tree 9 December 2017 22: 46 New
    +2
    Have you tried chamber cooling? Finning, as in air-cooled ICEs and ejection, as in Pecheneg. The machine is heavier, so aluminum on the casing and ribs, and there and aluminum plastic sleeves what
    1. Vadim237
      Vadim237 9 December 2017 23: 23 New
      +2
      Unless the barrel is made of cermet - instrumental, which would hold large cyclic: thermal, vibration and shock loads. But then we rest on the price of such weapons.
      1. family tree
        family tree 9 December 2017 23: 47 New
        +1
        Yes, I didn’t observe metal ceramics at Pecheneg, but I watched the complete set in one burst, and I didn’t spit. There, it’s more likely that they will crimp the steel chamber with an aluminum jacket, the expansion coefficient of the luminaire is greater, the adhesion will tear over time, cut and squeeze with rings, well, the output, if the rings can withstand the full wear of the barrel what
        1. Vadim237
          Vadim237 10 December 2017 21: 31 New
          +1
          And it’s better to make a sleeve of carbon fiber in general - with an aluminum “core”
        2. Vadim237
          Vadim237 11 December 2017 23: 20 New
          0
          You can also make a sleeve in which the bullet will be fixed with a magnetic ring.
    2. Operator
      10 December 2017 16: 32 New
      0
      With intensive burst shooting, the heat influx from the combustion of gunpowder is guaranteed to exceed the outflow of heat into the barrel air cooler.

      Only water cooling will help - see the Maxim machine gun.
  10. cannabis
    cannabis 10 December 2017 09: 02 New
    +2
    As one general said, “let's do analys!”. Engine revolutions of "Formula 1" machines are over 10 rpm, which means there is a mechanic that can withstand such a pace of work! Further .... airsoft players have shooters with containers of gelatin balls and cylinders of compressed gas. They work fine. Fans of pneumatics have Chinese AKMs with electric, shooting balls, and it hurts .... damn it! If you combine all the enti ideas in one model of the weapon of the future, and go back to round bullets of large caliber ...... well, it really takes your breath away from the prospects! The large caliber, with the multi-color gamut of the internal filling of round bullets, will make it possible to defeat any shit in the surveillance sector. The question arises - "Why fill the cylinder with working gas?" Correctly arises ... can experiment with ethylene oxide, like in a volume explosion bomb? Crumple skull, constructors .......
    1. Vadim237
      Vadim237 10 December 2017 21: 29 New
      +1
      It’s better to immediately get the railgun automatic - only it will weigh 10 kilograms.
    2. Michael HORNET
      Michael HORNET 11 December 2017 12: 48 New
      0
      At 50 meters ??? With a bruise kick? Not even funny, forgot to invite kindergarten
      1. cannabis
        cannabis 11 December 2017 12: 51 New
        +1
        You didn’t understand anything ....... then the deputy read?
  11. shuravi
    shuravi 10 December 2017 15: 11 New
    0
    In addition to promising, there are also so-called undervalued cartridges. For example, 7,62 x 25

    Which endured a rather significant part of the Second World War and is now undeservedly forgotten.
    Of course, weapons based on such a cartridge are not suitable for arming motorized rifle units.
    However, there is a niche for him now occupied by the ersatz.
    In particular, the issue of arming the crews of combat aircraft and helicopters has not yet been resolved intellectually. The same Afghan showed that a full-time PM during flights over unfriendly territory is clearly not enough.
    Therefore, the crews of the AKS-74U were additionally hastily armed.
    It would seem that you have resolved the issue? Only in part. The dimensions of the AKS-74U are still such that it is simply impossible to fix it on the pilot’s body so that it does not interfere with the flight in performing its functions, and if it is forced to leave it, it’s simply impossible.
    In addition, the probability of a weapon failing (failure, combat damage) does not disappear anywhere and it is very “insulting” when you have only PM, 18 cartridges for it and a bunch of already useless 5,45.
    In this case, the 7,62 x 25 cartridge is very attractive. Its dimensions allow you to create on its basis as a pistol, which is always in the pocket of your overalls and will not be lost, and in addition to it a longer-range weapon.
    1. Locksmith
      Locksmith 10 December 2017 16: 49 New
      0
      Quote: shuravi
      The dimensions of the AKS-74U are nevertheless such that it is simply impossible to fix it on the pilot’s body so that it does not interfere with the flight and, when forced to leave, is not lost.

      There are more modern models, Cedar, Cypress, PP2000, and "Ksenia" are a rather peculiar "device", in the 90s, one familiar "cop" reported that he was trying to stop the bus at a stationary PPS post, shooting on wheels was almost planted, almost clapped the carrier belay
      1. shuravi
        shuravi 10 December 2017 17: 15 New
        0
        They are not suitable for crews. Close combat. While the cartridge I mentioned allows you to create weapons with a range of 400-500 meters.
    2. Michael HORNET
      Michael HORNET 11 December 2017 12: 51 New
      0
      It's right. Rejection of 7,62x25 was very great stupidity. The cartridge would still be modern, and with some modernization would be an excellent cartridge for MPD
      A 7,62x33 revolving cartridge (327 Federal Magnum or 30 Carbine) would be appropriate to replace the stillborn PSM in a small 6-charge revolver
  12. missuris
    missuris 10 December 2017 17: 20 New
    0
    More bullets) better than bullets)
  13. Operator
    10 December 2017 21: 09 New
    0
    groks,
    Yes, all experienced and serial sleeves are made of aluminum alloys - pure aluminum is too weak.
  14. Operator
    11 December 2017 20: 08 New
    0
    prodi,
    The power of the propellant charge is proportional to its weight, and not the degree of prepress.
    The weight of the propelling charge of the telescopic and classic cartridges in the same caliber is the same.
    1. Aqela
      Aqela 10 January 2018 20: 19 New
      0
      Are there any differences in the course of burning a powder charge of pressed and bulk? It seems like even the shape of the powder grains has a role. request
      1. Operator
        10 January 2018 20: 24 New
        0
        Pressed burns a quarter slower.
  15. gromoboj
    gromoboj 12 December 2017 00: 23 New
    0
    If unused cartridges are removed from the barrel after firing, their cartridges lose their lacquer coating due to its burning out upon contact with the heated surface of the chamber, after which they are rapidly oxidized and the cartridges become unsuitable for further use.

    And what is someone collecting cartridges? Or is it a single cartridge that was sent to the barrel during firing?
    1. Aqela
      Aqela 10 January 2018 20: 21 New
      0
      No, but when the long line ends, the cartridge is fed into the heated chamber. If the shooting is not resumed again, then we have a cartridge case with a damaged protective layer in the chamber, which could be fraught ...
  16. Usher
    Usher 12 December 2017 15: 21 New
    0
    An outdated article that damn there is no plastic that holds a temperature of 500 degrees? I will not believe.
    1. Aqela
      Aqela 10 January 2018 20: 22 New
      0
      Considering that the author dwelled on this issue in particular, the counter-question arises: did you, milsdar, not read the article at all? request
  17. shinobi
    shinobi 17 December 2017 09: 32 New
    0
    The future lies with aluminum composites, but it looks like the industry will remain at a systemic dead end. The general concept of small arms has not changed for 60 years.
    1. Aqela
      Aqela 10 January 2018 20: 24 New
      0
      Considering that ammunition developed in the time interval from 1870 to 1970 is widely used ... good laughing About the systemic crisis is somehow poorly said! wink hi
  18. octogen
    octogen 14 August 2019 11: 53 New
    0
    In the shooter, reliability is important. Therefore, all these telescopic perversions will go to the forest. Often, in battles with ghosts in Afghanistan, the weapons of Soviet soldiers began to "spit" from overheating, but they worked, creating at least a barrage of fire. And all these options described in the article are only until the first good fight.

    A promising cartridge is the same cartridge case, possibly partially with a polymer sleeve, but a classic bottle shape. The cartridge is equipped with progressive burning gunpowder. Adapted to electric ignition options. The bullet may have a greater elongation and its elongated shank of a smaller diameter go far into the sleeve. So with the same caliber and the shape of the sleeve, you can increase the mass of the bullet and the range of aimed fire with it. What I wrote is cheaper than all these perversions from the article. And the money saved is better spent on electronic sights are different.
  19. Puhly67
    Puhly67 20 October 2019 13: 56 New
    0
    Americans under their composite cartridge 6.8. already testing machine gun / bullpup and assault rifle. by recalling the American pros. replacing the M249 machine gun with a bullpup. bad replacement. !! left-handed / right-handed. weight. They say it will be less than 9 pounds (4 ..... kg) It is not known how plastic will behave when shooting in long bursts. Well, the cherry on the cake trunks will be forged from Inconel (nickel-chrome alloy) In 2020-2024 they want to completely rearm .... let's see.