Automatic low-pulse cartridges caliber 5,45 mm
Soviet weapon Under the low-impulse patron, it was a materialized expression of the spirit of intense rivalry in the military field between the Warsaw Pact and the NATO bloc during the cold war. The emergence of a new "ammunition-weapon" complex from the main enemy demanded an urgent and effective response from our side. Possessing impeccable reliability, the Kalashnikov AKM 7,62-mm assault rifles, however, did not fully meet the increasing demands of the Armed Forces on the likelihood of hitting the target due to increased dispersion when firing bursts, as well as the large steepness of the trajectories of bullets. This was due to the fact that the high recoil impulse 7,62-mm of the automatic cartridge of the 1943 of the year (0,78 kgf / s) did not allow even the modernized Kalashnikov to achieve high accuracy of the automatic fire, especially when shooting from unstable positions. For a long time, domestic specialists conducted intensive search for ways to increase the combat effectiveness of the Kalashnikov assault rifle. Studies have shown that the accuracy of automatic firing is determined not only by the ballistic pulse of the cartridge and the recoil energy of the weapon, but also by the design characteristics of the sample itself (mass, moment of inertia, location of the centers of mass of the weapon and the moving parts of the automation), as well as dynamic characteristics moving parts).In the Soviet Union, the expediency of switching a hand-held automatic weapon to a smaller caliber than the existing 7,62 mm was scientifically grounded by V. G. Fedorov already in 1939, when he wrote that the range of a direct shot of an “intermediate” cartridge should be no less than that of a standard rifle cartridge. To reduce the mass-dimensional characteristics of the cartridges, he proposed to reduce their caliber to 6 – 6,25 mm. Back in 1945, V. G. Fedorov in his work “Study of further ways to improve the effectiveness of small arms firing” proved that the development of automatic small arms would be most promising if it developed towards a decrease in the caliber of cartridges. However, the official line pursued at that time by the leadership of the USSR People's Commissariat of Armaments and the Main Artillery Directorate of the USSR People's Commissariat of Defense, aimed at working out a set of small arms designed to use an 7,62-mm "intermediate" cartridge, did not take into account the conclusions of Fedorov. Along with subjective factors, this was also due to objective reasons - in the Soviet Union in the middle of the 1940-ies there was no technical and technological base for manufacturing small-caliber ammunition cartridges, and the weapons themselves.
Still, the very idea of creating a more effective ammunition-weapon complex was not stowed away. By the beginning of the 1960-s, domestic gunsmiths had gained some experience in creating promising systems of automatic infantry weapons, consisting of an automatic rifle and a single machine gun. They were developed under the experienced powerful 7,62-mm single automatic machine-gun cartridge design S. I. Vetoshkina. In this direction, the Soviet designers moved in parallel to our opponents, whose bitter negative experience was taken into account when conducting subsequent work on promising small arms systems in the USSR.
The US armed forces, only recently re-armed with 7,62-mm M-14 automatic rifles, developed under the powerful NATO rifle-and-machine gun cartridge 7,62 x51 of NATO, had already reaped the sad fruits of such a hasty decision. And this, in turn, made the US military command already in 1957 take a decision in principle to start developing automatic weapons for a low-momentum cartridge, which was thus a turning point in all subsequent stories modern small arms. To a similar conclusion about the low efficiency of new ammunition of normal rifle caliber came after large R & D, Soviet designers. The high level of technical solution of new domestic cartridges and the certain reduction in recoil momentum achieved at the same time did not allow to solve the main task assigned to the new “ammunition - weapon” complex: to increase the effective range by one and a half times in relation to the standard range of small arms, calculated under 7,62-mm automaton cartridge arr. 1943 of the year.
In addition, research was conducted in the Soviet Union on the pattern of dispersion of bullets depending on recoil pulses, muzzle compensators, etc. The development of new ammunition caliber 4,5 mm and 6,5 mm was carried out, various designs of non-classical bullets and weapons for them were studied.
Thus, in the 1960 – 1962 years, the engineers and designers of the SRI-61, V. P. Gryazev, A. G. Shipunov, D. I. Shiryaev, I. Kasyanov, O. P. Kravchenko, and V. A. Petrov, created low-impulse cartridges with subcaliber feathered (arrow-shaped) bullets with leading elements (plastic pallets) detached in flight. DI Shiryaev developed for this cartridge a prototype of the automatic machine AO-27, relatively light and steady when fired by automatic fire. The large flatness of the arrow-shaped bullet trajectory to some extent compensated for the low accuracy of the battle. However, the results of accuracy, shown when firing from AO-27, turned out to be much lower than planned, so all work on similar weapons was stopped. But this did not mean a complete rejection of the idea, since it was able to increase the effectiveness of individual automatic weapon fire, and after a few years a new modified rifle cartridge with a arrow-shaped bullet appeared, designed by VN Dvoryaninov, an engineer of the same research institute-61, for a rifle machine gun Goryunova SGM and the Dragunov SVD sniper rifle. Similar studies were also widely conducted in the United States, but the negative results shown by these munitions during the tests forced the Americans to curtail all work in this direction.
Simultaneously with the failure, which ended work on the creation of a new domestic “ammunition-weapon” complex, the leadership of the USSR Ministry of Defense receives information about the new AR 15 high-performance rifles (XM 16) developed for the low-pulse cartridge 5,56 x45 and 193 adopted for pilot operation in american army. Soon, in the hands of Soviet military specialists, there were fighting trophies from South Vietnam - the weapons and ammunition itself. And these facts made the military seriously think that the enemy is ahead of us in this area of military-technical research, since the Americans in 1961 had already conducted the final stage of military tests of a weapon designed for a cartridge with a reduced recoil momentum. While in the Soviet Union only recently, the 7,62-mm AKM assault rifle, which was already inferior to the perspective AR 15 rifle in some parameters, was adopted.
The evolution of small arms led to the conclusion that while maintaining the classical scheme that uses powder charge as a source of energy for throwing bullets, reducing the caliber will increase the initial velocity of the bullets. Thus, it will be possible to achieve the flatness of the trajectory of the bullets, reduce the mass of the weapon itself and increase the ammunition wearable by the shooter (without increasing the total weight load). The use of new designs of bullets and cartridges, new materials of the cores of bullets made it possible to provide the required damaging properties of bullets of reduced caliber. At the same time, theoretical calculations have shown that the characteristics of the 5,6-mm cartridge are different for different combat conditions. In close combat, as a rule, offensive, when firing from unstable positions at short distances, bullets of this caliber have a maximum penetrating effect; therefore, to reduce the effectiveness of hitting targets, reduction of dispersion was of primary importance, which could be achieved both by decreasing the power of the cartridge and by reducing the momentum recoil, but at the same time it influenced the decrease in the initial velocity of the bullet. In defensive combat, shooting was carried out at much longer ranges and mainly from stable positions, therefore dispersion here is much smaller, and the decisive factor was the flattening of the trajectory and the penetrating action, which could only be achieved by increasing the power of the cartridge. The contradiction between the increase in the initial speed of the bullet and its mass and the decrease in these characteristics for different combat conditions forced the Soviet gunsmiths to look for the best option.
Therefore, in the 1961 year in the Soviet Union, the specialists of the Scientific Research Institute-61 began complex research on reducing the recoil momentum of weapons and developing a new 5,6-mm cartridge with a high initial speed based on the re-pressed sleeve 7,62-mm automatic cartridge mod. 1943 of the year.
The first stage of research work, which the Soviet Union embarked on in 1963, was aimed at creating a new ammunition-weapon complex on peremovane AKM automatic rifles of 5,6 caliber mm. As a result of the research, it turned out that the new 5,6-mm cartridge had a smaller recoil momentum on 35 percent than the 7,62-mm cartridge mod. 1943, and this allowed 1,8 times to reduce the recoil energy of the weapon. The research artillery test range of the USSR Ministry of Defense in the Vsevolozhsk district of the Leningrad region, analyzing the possibilities of using new, the most optimal design schemes for small arms, in its conclusion indicated that “the most effective means of improving the accuracy of automatic strikes when shooting from unstable positions is to reduce the recoil momentum when fired.
An important factor contributing to this conclusion of our military experts was the fact that the AR 15 rifle exceeded the AKM assault rifle not only in one of its main parameters - accuracy of combat, but also in terms of the probability of hits. Thus, the most realistic way of increasing the combat effectiveness of individual automatic weapons could be the adoption of a new intermediate cartridge with a reduced recoil impulse and the development of a next-generation submachine gun for it.
As a result of long-term work by a group of specialists - ammunition workers of TsNIITOCHMASH (Klimovsk, Moscow Region) under the leadership of V. M. Sabelnikov composed of L. I. Bulavskaya, B. V. Semina, M. E. Fedorova, P. F. Sazonova, V. I. Volkova, V.A. Nikolayeva, E.E. Zimin, P.S. Korolev and others. A completely new domestic 5,6-mm low-impulse cartridge with a steel core bullet and with a length of 39 mm was created, which was originally named "13 MJV." Subsequently, when the designation of the caliber was adopted, corresponding to the real diameter of the bore through the rim fields - 5,45 mm, the cartridge received the GRAU index - 7 Н6.
Designers managed to achieve with a smaller bullet weight (3,42 g instead of 7,9 g for AKM and 3,56 g for AR 15) reducing the maximum permissible level of recoil momentum of automatic cartridges (0,49 kgf / s against 0,78 and 0,58 kgf / s, respectively) and at the same time increasing the range direct shot, i.e. the range at which the height of the trajectory is equal to the height of the target (440 m instead of 350 and 426 m, respectively), which, by the way, exceeded the similar characteristic of the 7,62-mm rifle cartridge mod. 1908 of the year. The peculiarity of his bullet was that the steel core 5,45-mm cartridge 7 H6 had a lead shirt, and the bullet shell was steel, clad with tampacom. Such a device of bullets provided its better durability and greater breakdown effect than that of 5,56 x45 M.193 cartridges. The excellent aerodynamic shape of the bullet of the new Soviet 5,45-mm cartridge contributed to its high ballistic performance (initial speed 900 m / s). In addition, its design was similar to the 7,62-mm bullet taken from a single automatic-machine-gun cartridge. It also had a head space, which, along with the optimally chosen rifling pitch for this ammunition, provided the small-caliber bullet with the same 7,62-mm bullet of the cartridge. 1943 year slaughter on the entire range of direct shot. Only by the end of the 1960-s were the recommendations of VG Fedorov finally realized, which over the years before 30 had defended his point of view on the development of intermediate small-caliber cartridges.
Improvement of the most widespread type of small arms of the Soviet army - Kalashnikov assault rifles was largely determined by the successful development of new 5,45-mm assault rifles. For shooting from the AK 74 AK, 5,45-mm low-impulse cartridges mod. 1974 of the year with steel liners:
- with an ordinary bullet with a steel core (PS),
- with a tracer bullet (T),
- with a reduced speed bullet (CS).
For imitation of shooting, blank cartridges were used (initially - without a bullet, and later - with a plastic bullet), which were automatically fired using a special sleeve, screwed onto the muzzle of the barrel, instead of the muzzle-compensator brake.
With the initial speed 900 m / s of the AK 74, the bullet received the rotation speed 4500 revolutions per second, and the RPK 74 with the initial speed 960 m / s - 4530 revolutions per second). This ensured a high stability of the bullet on the flight, almost equivalent to the stability of the bullet of the NATO 5,56 cartridge (adopted to supply the armies of the North Atlantic bloc only in the 1980 year). To increase the striking effect in manpower, the bullet layout was chosen so that the bullet in flight was “on the verge of stability” and lost stability when it entered a denser environment.
The new 5,45-mm cartridge 7 Н6 with a flat trajectory made it possible to increase the range of a direct shot at the growth figure from 525 (from AKM) to 625 m (from AK 74). The sighting range of 5,45-mm machine guns (machine guns) was 1000 m. The effective range of ground targets from the machine gun (compared to AKM) increased to 500 m, from a machine gun - to 600 m; on airplanes, helicopters and parachutists - from a machine gun and a machine gun - to 500 m.
Concentrated fire on ground group targets can be fired from machine guns and light machine guns at a distance of up to 1000 m. The direct shot range of the 74 AK machine gun was: for the chest figure - 440 m, for the traveling figure - 625 m; in the RPK 74 – 460 and 640 light machine gun (respectively).
However, as compared with AKM, the 74 automatic rifle reduced the range of slaughter action of the bullet from 1500 to 1350 m, that is, the ratio between the range of slaughter and effective range decreased from 3,75 to 2,7 times. Dispersion when shooting AK 74 in short bursts from stable positions (lying with the stop or standing in the trench) at a distance of up to 800 m began to make: the total dispersion deviation in height total - 0,48 m, side total - 0,64 m. Reducing the weight of the cartridge allowed the soldier to increase 100 caliber cartridges 7,62 mm to 165 cartridges 5,45 mm caliber cartridges without increasing the mass of the weapon. Increasing the initial speed of the bullet, flattening the trajectory, reducing the recoil impulse allowed to increase the combat effectiveness of the 5,45-mm assault rifle 74 AK in 1,2 – 1,6 times in comparison with the 7,62-mm AKM assault rifle. Bullet steel 7 N6 cartridge core is fired from the AK 74 / LMG RPK74 provide penetration 5-mm steel sheet (when 80-90 percent penetrated) at a distance 350 m, steel helmet (helmet) - on 800 m range staffing domestic army body armor Zh86 – 5 - on 550 m.
However, the work on improving the ammunition-weapon complex in the Soviet Union did not end there. New trends in military affairs, as well as the military exploitation by the Soviet army in Afghanistan, 5,45-mm Kalashnikov assault rifles AK 74 led to the need to seriously modernize both the weapon and the 5,45-mm cartridge. Extensive use of personal armor in the armies of many countries (in particular, body armor) in the 1980-ies showed that their defeat when firing from machine guns is not guaranteed. Further development of personal protective equipment, the use of body armor with plates made of durable titanium alloys dramatically reduced the effectiveness of the 7 H6 bullet with heat-strengthened core due to the imperfect shape of the core, which is not able to penetrate the titanium alloy plate even at close distances. Therefore, Soviet gunsmiths had to look for new ways to increase the penetration of bullets of low-pulse automatic cartridges. Already in 1986, the penetration effect of 5,45-mm cartridges was significantly increased due to the use of heat-strengthened core of increased hardness 7 Н6 M in the bullet design: the penetration distance of protected targets, in particular steel helmets (helmets), grew from 800 to 960 m, armor with titanium plates from 20 to 200 m. From the beginning of the 1990-ies, almost simultaneously with the adoption of the 5,45-mm modernized AK 74 M automatic rifle (in 1991), ammunition with new bullets with increased penetration rate is being used, complementing the infantry’s weapon system with the newly developed automatic weapon. So, in 1992, the core was once again refined, making it more pointed and heavy. With the same initial speed, a bullet of increased breakdown action (PP) with a heat-strengthened core (7 index Х10) now ensured the penetration of a regular Russian army X85-T bullet-proof vest (with 40 percent through penetration) at a range 200 m, and a heavy X95 bulletproof vest-x. 50 m range, while the 5,45-mm 7 H6 M bullet with a steel core penetrated an X85-T body armor only at 90 m, and the X95-K body armor was not provided at all firing ranges. As a result, the 5,45-mm cartridge 7 H10 with a bullet PP at the penetration action is very close to the 7,62-mm rifle cartridge mod. 1908 of the year, and their effectiveness in penetration of obstacles in comparison with the bullet of the cartridge 7 H6 increased 1,84 times. However, the provision of a given level of direct shot and punching action required an increase in the power of the 5,45-mm cartridge, which in a certain way affected the increased impulse of its recoil and a sufficiently large dispersion of bullets when shooting AK 74. In addition, the adoption on the supply of a new cartridge with a bullet of increased breakdown action had a reverse side. The life expectancy of the shafts of AK 74 M AK when firing a new cartridge has sharply decreased. Therefore, the designers had to carry out a number of research projects to increase the survivability of the bore. It should be noted that the reserves of 5,45 mm bullet in terms of increasing the effectiveness of hitting obstacles are far from exhausted, work in this direction continues.
At present, the following main versions of 5,45-mm low-pulse automaton cartridges are used in the Russian Armed Forces.
5,45-mm automatic cartridge mod. 1974 of the year with a bullet with a steel core PS (index 7 H6)
Combat cartridges with bullets of all types are produced only with steel, covered with dark green lacquer bottle-shaped sleeve with no protruding flange and groove. The propellant charge is spheroid powder SFO33, with 1989 of the year replaced by CNF30 / 3,69 brand powder.
A pointed bullet with a diameter of 5,65 mm, with an elongated head part with a rear cone without a belt, consists of a steel stamped core (steel StNNXX) with a mass of 10 g; a lead shirt and a bimetallic (steel, clad with tampacom) casing. The lead shirt does not reach the end of the shell, and in the front part of the bullet, between the inner surface of the head part of the shell and the lead shirt there is a cavity of length 1,43 mm, contributing to the displacement of the center of gravity of the bullet somewhat back, which lowers the stability of the bullet when meeting with the target. The edges of the shell in the tail section of the bullet are rolled up with support on the bottom of the core. The bullet is not painted. In all 5 mm caliber ammunition cartridges, except for bullets with PP bullets, red lacquer is used to seal the butt of the bullet with the edge of the cartridge sleeve and the capsule butt, which does not have a distinctive color. Currently not available.
5,45-mm automatic cartridge mod. 1974 of the year with a bullet of increased penetrability PP (index 7 H10)
In the 1992, a new modification of the 5,45-mm automaton cartridge arr. 1974 of the year with a bullet of increased penetrability of PP, developed by the creative team of designers and technologists of the Barnaul machine-tool plant. The bullet of increased penetrability of PP obtained a stamped elongated steel heat strengthened core of greater mass. The core, made of steel 70 (mass 1,72 g) or 75 (mass 1,8 g), has a more streamlined and lively-shaped head, a flat top with a diameter of 1,8 mm and a recess in the bottom center (unlike the PS bullet). The bullet of increased penetrability of PP ensured the penetrability of plates from alloys at a distance of 100 meters - 100 percent and steel plates with a thickness of 14 mm at a distance of 100 meters of at least 80 percents.
5,45-mm assault rifle mod. The 1974 of the year is sealed into a regular wooden cartridge case for 2160 pieces each. In each box are placed two metal sunset boxes, in which 1080 cartridges are laid. There is also a capping option in which packs of cartridges are not placed in steel boxes, but in paper-proof bags (120 cartridges), four packs of 30 cartridges each. At the same time on the wooden box is the inscription "waterproof bags." The closure contains special abbreviated alphanumeric characters. On boxes and boxes containing cartridges with special bullets, an additional colored strip is applied, corresponding to the distinctive color of the cartridge.
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