Caliber 5.39 from what weapon. Blank cartridges for AK (5.45x39 mm)

The debate about which caliber of automatic weapons is better - 7.62 or 5.45 mm has been going on since 1974, when Soviet Army The 5.45 mm Ak-74 assault rifle was adopted. It is obvious that a universal machine gun or any other weapon does not exist. Each model has its own advantages and disadvantages. Preference is given to weapons that have a large range of positive qualities. When the author of these lines was studying at a military school (1989 - 1993), the university was re-equipped with brand new Ak-74s. The first thing that caught my eye was that after zeroing in the machine guns, many cadets’ shooting accuracy increased, and the bullets fell more closely together. But shooting at a training ground is one thing, but real combat is completely different. In this article we will make an attempt to figure out which of the two calibers still has a greater combination of positive qualities.

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It is no secret that the development of individual small arms over the past two centuries has been accompanied by a constant decrease in caliber. This is due to the development of technology in the production of both weapons and ammunition. Thus, by the middle of the 19th century, the usual caliber of long-barreled weapons was considered to be 0.4 - 0.5 inches (10.0 - 12.7 mm). In the last twenty years of the 19th century, a shift began to smaller caliber weapons, typically on the order of 0.3 inches (7.62 mm or so, in the 7-8 mm range). Already in the first half of the 20th century, repeated attempts were made to further reduce the caliber of weapons to 7 millimeters or less, as well as to reduce the power of standard rifle ammunition, especially after the advent of automatic weapons.
During World War II, ammunition of reduced power began to appear in the armies of the world, still having a standard rifle caliber of 7.62 - 8.0 mm.
But the problem of reducing the caliber of their rifles was first seriously addressed in the United States, when they adopted the M16A1 assault rifle in the mid-1960s. As soon as the practical experience of the Americans confirmed the possibility and usefulness of further caliber reduction, full-scale work in this direction began in other countries, including the USSR.
Our answer
Since the second half of the 1960s, based on the standard 7.62 mm cartridge, 5.6 mm caliber cartridges were developed, and by the beginning of the 1970s, a new 5.45 mm caliber cartridge was developed, which had an elongated bullet with a combined steel and lead core and cavity in the nose. The initial bullet speed was about 900 m/s, total mass cartridge weighs 10.2 grams, 6 grams less than the mass of a 7.62 mm cartridge (16.2 g), which, with a portable ammunition load of 8 magazines (240 rounds), results in a weight saving of 1.4 kg.
The new cartridge also had a significantly flatter bullet trajectory, which increased the direct shot range by almost 100 meters. Due to the design features of the bullet, when it hit the body, it began to tumble, causing more severe wounds than usual.
As the initial weapon for the new cartridge, it was decided to use the Kalashnikov assault rifle and light machine gun, already tested and mastered in production and service, with the minimum necessary changes, and in the future to develop and put into service a more advanced set of weapons for the new cartridge. In 1974, a 5.45 mm caliber complex was adopted, consisting of an AK-74 assault rifle (basic version), an AKS-74 assault rifle (version with a folding stock for the Airborne Forces) and an RPK-74 light machine gun. At the end of the 1970s, the shortened AKS-74U assault rifle was also adopted.
Later, the so-called “night” versions of the AK-74N appeared, which had a side rail for attaching infrared night sights. Currently, the main option is the AK-74M assault rifle, which is entering service Russian army since the early 1990s. This assault rifle is distinguished mainly by the fact that it immediately replaced the AK-74, AKS-74 and AK-74N, due to the fact that it has a black plastic stock folding on the left side (outwardly similar to the AK-74 stock of later series), as well as a universal a bar for attaching sights (both night and day) on the left side of the receiver.
When the new 5.45 mm caliber cartridge was adopted by the Soviet Army, it was understood that the modernized Kalashnikov AK-74 and RPK-74 assault rifles and light machine guns adopted with it would eventually be replaced with more advanced and effective small arms. The research and then competition topic under the code name “Abakan” was precisely started to create a fundamentally new model of individual small arms of 5.45 mm caliber to replace the AK-74. The victory in the competition went to the model developed by designer Gennady Nikonov at IZHMASH. In 1994, the Nikonov assault rifle was officially adopted by the Russian army under the designation AN-94.
However, for a number of reasons this machine gun was not widely used among the troops.
"For" and "against"
Which caliber is better? The question is quite complex. The 5.45 mm bullet has a smaller cross-sectional area. This means that it experiences less air resistance, its flight trajectory is more flat, the direct shot range is greater, the accuracy is higher and the bullet retains its destructive power at a fairly large distance. The presence of a muzzle brake-compensator also increases accuracy (the AKM has a compensator installed). These are the advantages. And the disadvantages are also related to the mass of the bullet. Since it is smaller than the 7.62 mm caliber, the flight path is more influenced various kinds obstacles and weather conditions, which must be taken into account when using weapons in the mountains, in the greenery.
Bullets of 7.62 mm caliber are correspondingly heavier and have large area cross section. This (primarily mass) gives an advantage during combat operations in forest and mountainous areas, in unfavorable weather conditions. The branches of a 7.62 mm bullet are simply cut off, and trees with a diameter of 10-15 centimeters are pierced.
Disadvantages: 7.62 mm bullets have a more upward flight trajectory and, due to air resistance, lose the resulting energy faster. The direct firing range and accuracy of 7.62 mm bullets is less than that of 5.45 mm, since powder charge more and the impact is stronger. The buttstock of 7.62 mm assault rifles has a greater angle of inclination relative to the barrel than that of a 5.45 mm assault rifle, and, as a result, they jerk more strongly when fired.
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Lethal effect
7.62 mm. The ammunition for the Kalashnikov AK-47 or AKM assault rifle is equipped with a spindle-shaped bullet with a solid shell made of copper-plated steel. There is a large steel core inside. The space between the core and the cladding is filled with lead. Typically, in the human body, this bullet travels a distance of 23-26 cm with the head part forward, and then abruptly changes position. The wound is characterized by minimal tissue rupture. Typically, if the bullet misses the bones, it will leave small pinpoint entry and exit wounds with minor muscle tearing. Moreover, when hitting large internal organs the severity of the injury can be significant, often incompatible with life.
5.45 mm. The bullet is used in ammunition for the AK-74 assault rifle. It has a solid metal shell made of copper-plated steel. There is a large steel core inside and a lead liner in front of it. Characteristic feature is a free space of about 5 mm in length at the head. Its purpose is to shift the center of gravity towards the bottom, which causes the bullet to change position at the initial stage of its journey in human tissue. In addition, at the moment of impact, the lead present inside the bullet moves forward into free space. The movement of lead does not occur symmetrically, and this is one of the reasons for the sharp curvature of the bullet’s trajectory when passing through tissue. However, this behavior of the bullet does not greatly increase its damaging effect. Although the bullet changes position within 7 cm of penetrating the body, a significant gap occurs only at the final section. All small-caliber pointed bullets that are not subject to deformation end their path through tissue with the bottom part forward, since that is where the center of gravity is located. When entering tissue, factors such as the shape of the bullet and the location of the center of gravity are stronger than the stabilizing effect of rotation.
Expert opinion
SHIRYAEV Dmitry Ivanovich, for 49 years was the leading designer of the FSUE "TSNIITOCHMASH", worked at the Klimovsky specialized cartridge plant:
- As soon as the Ak-47 was put into service, the troops became convinced that firing bursts from this machine gun from an unstable position (standing, kneeling) was not very effective. Two bullets still somehow hit the target, the third goes to the side.
The military believed that with factory modification this could be eliminated. Were held great work in the specialized research institute-61. But the problem could not be solved. The machine was improved, but still not as much as needed.
Meanwhile, the Americans hastily switched to the 5.60 mm caliber, and for the same reason that I mentioned above. Then the director of NII-61, Viktor Maksimovich Sabelnikov, began developing the 5.45 mm cartridge at the institute. Active testing was carried out in one of the military districts. This topic was taught by the famous weapons engineer Lidia Ivanovna Bulavskaya. Moreover, Mikhail Timofeevich Kalashnikov, I will say this, did not contribute to this work. As a result, the cartridge was tested and good results were obtained.
In the meantime, feedback was received from the troops, some quite critical. They say that when these bullets hit almost a blade of grass, they lose stability. Skeptics were invited to the NII-61 training ground, where various obstacles were made, and the negativity prescribed for the 5.45 mm cartridge was not confirmed. Then, by the way, Lidia Ivanovna suggested that next time the tests should be carried out with the critics’ money.
In 2000, I was in Chechnya and met with a Chechen - the commander of a detachment who fought on our side. He said that when he goes on operations, he knows that the enemy will have automatic weapons of 5.45 mm caliber. He protected his UAZ with discs from the cultivator and was calm. But the fact is that only the first 5.45 mm cartridges - 7M6 - were rather weak in penetration. Later, the 7M10 cartridge was developed, which penetrates a 16-mm iron sheet (steel-3) at a 100-meter distance, which was repeatedly demonstrated at the arms exhibition in Abu Dhabi.
In my opinion, conversations about the advantages of the 7.62 mm cartridge are quite subjective. Some experts pass them on to each other as legends. The overwhelming majority of domestic weapons scientists, designers and engineers believe that there is no alternative to switching to the 5.45 mm caliber. Especially when we're talking about about the 7M10 cartridge, which, by the way, very few of them arrived in Chechnya during the first and second campaigns. Do not forget that large-scale scientific research and numerous tests have been carried out to confirm these conclusions.
Still - 5.45 mm
Thus, the advantage of the 5.45 mm cartridge is obvious. Here is the opinion of Russian gunsmith scientists: currently the 5.45 mm cartridge remains best choice for individual automatic small arms. Further modernization of this ammunition will allow it to continue to successfully compete with foreign analogues.

5.45x39 Discussions about the question do not subside - why is it needed?

Let's try to figure it out.

To begin with, I will leave aside the value of this cartridge for nostalgic Saeg owners who dress their hunting rifles in varnished plywood and spray-paint polyamide magazines plum color. This has always been unclear to me, so to each his own.

Next, I’ll note that stories are from the series A friend of mine, Warrant Officer Zink, promised to fit me some tracers"in practice, they remained in the dense 1990s. Now some kind of order has been established in the army, taking into account weapons and consumables, and the likelihood of unnoticed or writing off a carload of machine gun cartridges is, of course, not completely zero, but this is a rarity that cannot be It’s really worth investing in. If it were different, then the hobbits would not have experienced extreme shortages of weapons and ammunition, gradually re-equipping with more and more ancient historical artifacts and stupid homemade products.

And finally Let’s not forget about the established law enforcement practice regarding the illegal trafficking of military ammunition of the same caliber as civilian ones. If ten to fifteen years ago they turned a blind eye to the hunter’s availability of cartridges with cores (let’s be honest - there was a lot of chaos), now two or more live cartridges are perfectly aroused and worked out 222h1, and having a permit for a Tiger or Saiga of a similar caliber - is not a mitigating circumstance.

Yes, a cunning lawyer can try to come up with a line about a fantastic confusion of live cartridges with civilian ones, which occurred in an unspecified place, at an unspecified time, etc., but this is only one of the lines of defense, and in no way a rehabilitating circumstance.

So no need to mess with army ammo- that’s my advice. Not those times.

Well, let’s actually talk about the material part.

External ballistics.

Cartridge 5.45x39 5.56x45 is almost the same type, and it’s worth comparing it with. Let's take two Saiga-MK carbines with 415mm barrels.

The excess tables look like this:

photo: popgun.ru/viewtopic.php?f=281&t=666649&start=150

Those. rough, 5.45x39 very close to the powerful 4 gram Barnaul-223. However, as the table clearly shows, the .223 is a little heavier and more powerful at launch, but has a slightly less flat trajectory, a little more recoil, and loses energy and speed faster. As a result, the difference in the recoil of a shot, 5J versus 6J, allows you to shoot from a 3kg 5.45 weapon at the same speed as from a similar 4kg 5.56 weapon.

Besides, advantage in direct shot range, for example, according to the Alpha metric target IPSC, looks like this:

photo: oswald-lh.livejournal.com/42471.html

Why is this happening?

With similar weight and caliber, the relative length of the 5.45 bullet is greater than that of the 5.56, and therefore the ballistic coefficient of the domestic cartridge is better.

It didn't happen by chance– our cartridge was made in response to the American one, and the creators tried to make it at least not worse, but better.

As a result, roughly, if a .223 carbine can shoot into the scoring zone without vertical corrections at 300 meters, then with an AK-74 clone this can be done at 350 meters.

Seems like an insignificant difference, but from these pennies comes victory in sports.

Wound ballistics.

This is even more interesting. The 5.56 cartridge was created for weapons with a 510mm barrel, and any carbines in the AKM format are “sawn-off” by default. At the same time, the OD of this FMJ and HP cartridge is based on the destruction of a short bullet in an obstacle due to high speed flight.

As soon as the speed drops below 700m/s, such destruction does not occur, and the 5.56 jacketed bullet begins to work like an ordinary small bullet, and the expansion does not open.

The effect is known and can only be treated by using an SP half-shell, but such bullets are less reliable when chambered in semi-automatic weapons and have a number of other legal disadvantages.

That is, for 5.56 a longer barrel is desirable, optimally 500mm, not 350mm, like the Saiga-MK03 class weapon. In the case of 5.45, we have the well-known effect of a long “bullet with a displaced center of gravity”, which, at almost all ranges of speeds and distances, due to its length, tips over after about 10 cm of passing through the target, producing a very stable traumatic effect.

And this effect can be achieved on weapons with any barrel length– from “knot” 214mm, to RPKshny – 590mm. That is, the AP does not depend on the length of the barrel, and in the case of a domestic caliber, you can have a weapon that is not only effective on paper in compact dimensions. Separately for imported ammunition.

I often read the opinions of beginners and theorists rifled weapons about the use of imported ammunition, which should increase accuracy to fantastic levels. Unfortunately, in my experience of shooting p.308 and p.223 at IPSC and just at the shooting range, the range of available imported cartridges in Russia is actually quite small. And the quality of these cartridges for a specific barrel often turns out to be much lower than expected for that kind of money.

I'm not calling throw everything away and switch to only products from domestic cartridge factories. It’s just that you shouldn’t immediately discard it - from a Saiga you will most likely shoot with an ordinary Barnaul or Centaur, so the advantage of the existence somewhere in the world of high-precision cartridges in your caliber is very far-fetched.

Conclusions.

It will be extremely interesting if domestic factories do produce a civilian AKMoyd in 5.45x39. This will be an extremely interesting complex, both for sport and as a NAZ weapon “just in case.”

The only question is the price, quality of execution and timing of the appearance of such a complex. For me personally, the new caliber is interesting in the possibility of creating a weapon for it weighing 3 kg with a barrel length of 350 mm, having a rate of fire and terminal effectiveness comparable to more heavy weapons with a longer barrel under .223 caliber.

Under the low-impulse cartridge was a materialized expression of the spirit of intense rivalry in military field between the Organization Warsaw Pact and the NATO bloc in the era cold war. The emergence of a new ammunition-weapon complex from the main enemy required an urgent and effective response on our part. Possessing impeccable reliability, the 7.62-mm Kalashnikov AKM assault rifles, however, did not fully meet the increasing requirements of the Armed Forces for the probability of hitting the target due to increased dispersion when firing in bursts, as well as the high steepness of bullet trajectories. This was due to the fact that the large recoil impulse of the 7.62-mm machine gun cartridge model 1943 (0.78 kgf/s) did not allow even the modernized Kalashnikov assault rifle to achieve high accuracy of combat with automatic fire, especially when firing from unstable positions. Long time domestic specialists were intensively searching for ways to increase the combat effectiveness of the standard Kalashnikov assault rifle. Research has shown that the accuracy of fire from a machine gun is determined not only by the ballistic impulse 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 moving parts of the automation), as well as dynamic characteristics (rate of fire and impacts moving parts).

In the Soviet Union, the feasibility of switching manual automatic weapons to a caliber smaller than the existing 7.62 mm was scientifically substantiated by V. G. Fedorov already in 1939, when he wrote that the direct shot range of an “intermediate” cartridge should be no less than from a standard rifle cartridge. To reduce the weight and size characteristics of cartridges, he proposed reducing their caliber to 6–6.25 mm. Back in 1945, V. G. Fedorov, in his work “Study of further ways to increase the efficiency of shooting from small arms,” argued that the development of automatic small arms will become most promising only if it develops in the direction of reducing the caliber of cartridges. However, the official line pursued at that time by the leadership of the People's Commissariat of Armament of the USSR and the Main Artillery Directorate of the People's Commissariat of Defense of the USSR, aimed at developing a complex of small arms designed to use the 7.62-mm "intermediate" cartridge, did not take into account Fedorov's conclusions. Along with subjective factors, this was also due to objective reasons - in the Soviet Union in the mid-1940s, the arms industry enterprises lacked the technical and technological base for the production of both small-caliber combat cartridges and the weapons themselves.

And yet, the very idea of creating a more effective ammunition-weapon complex was not shelved. By the early 1960s, domestic gunsmiths had accumulated some experience in creating promising automatic infantry weapon systems, consisting of an automatic rifle and a single machine gun. They were developed for an experienced powerful 7.62-mm single automatic machine-gun cartridge designed by S. I. Vetoshkin. In this direction, Soviet designers moved parallel to our opponents, whose bitter negative experience was taken into account when carrying out subsequent work on promising small arms systems in the USSR.

The US Armed Forces, which had only recently rearmed themselves with 7.62 mm M-14 automatic rifles, designed for the powerful 7.62 x51 NATO rifle and machine gun cartridge, were by this time already reaping the sad fruits of such a hasty decision. And this, in turn, forced the American military command already in 1957 to make a fundamental decision to begin the development of automatic weapons chambered for a low-pulse cartridge, which thus became turning point in all subsequent modern small arms. Soviet designers came to a similar conclusion about the low effectiveness of new normal rifle caliber ammunition after conducting extensive R&D. High level technical solution for new domestic cartridges and the resulting certain reduction in recoil impulse still did not allow us to solve the main task set for the new “ammunition-weapon” complex: to achieve an increase in effective firing range by one and a half times in relation to the standard small arms complex designed for 7.62 mm automatic cartridge mod. 1943.

Along with this, research was carried out in the Soviet Union in the field of the pattern of bullet dispersion depending on recoil impulses, the design of muzzle compensators, etc. New ammunition of 4.5 mm and 6.5 mm calibers was being studied, various design options for non-classical bullets and weapons under them.

Thus, in 1960–1962, engineers and designers of NII-61 V. P. Gryazev, A. G. Shipunov, D. I. Shiryaev, I. Kasyanov, O. P. Kravchenko and V. A. Petrov created low-pulse cartridges with sub-caliber feathered (arrow-shaped) bullets with leading elements that separate in flight (plastic trays). D. I. Shiryaev developed for this cartridge prototype the AO-27 assault rifle, relatively light and stable when fired with automatic fire. The greater flatness of the trajectory of the arrow-shaped bullet to a certain extent compensated for the low accuracy of the battle. However, the accuracy results shown when firing from the 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 abandonment of the idea, since it was capable of increasing the fire efficiency of individual automatic weapons, and within a few years a new modified rifle cartridge with a swept bullet appeared, designed by the engineer of the same NII-61 V. N. Dvoryaninov for re-barrel heavy machine gun Goryunova SGM and sniper rifle Dragunov SVD. Similar studies were also widely carried out in the United States, but the negative results shown by these ammunition during tests forced the Americans to curtail all work in this direction.

Simultaneously with the failure that ended work on the creation of a new domestic “ammunition-weapon” complex, the leadership of the USSR Ministry of Defense received information about new high-performance rifles AR 15 (XM 16), developed for the low-pulse cartridge 5.56 x 45 M 193, adopted for the experimental operation in American army. Soon, military trophies from South Vietnam - the weapons and ammunition themselves - ended up in the hands of Soviet military specialists. And these facts forced the military to seriously think that the enemy was ahead of us in this area of military-technical research, since the Americans in 1961 were already conducting the final stage of military testing of a new weapon designed for a cartridge with a reduced recoil impulse. While in the Soviet Union only recently the 7.62-mm AKM assault rifle was adopted, which was already inferior to the promising AR 15 rifle in some respects.

The evolution of small arms has led to the conclusion that while maintaining classical scheme, which uses a powder charge as an energy source for throwing bullets, reducing the caliber will increase the initial speed of the bullets. In this way, it will be possible to achieve a flat flight trajectory of bullets, reduce the weight of the weapon itself and increase the ammunition carried by the shooter (without increasing the overall weight load). The use of new designs of bullets and cartridges, new materials of bullet cores made it possible to provide the required damaging properties bullets of reduced calibers. At the same time, theoretical calculations showed that the characteristics of the 5.6 mm cartridge are not the same for various conditions battle. In close combat, usually offensive, when firing from unstable positions at short ranges, bullets of this caliber have maximum penetrating effect, therefore, to increase the effectiveness of hitting targets, reducing dispersion became of primary importance, which could be achieved by both reducing the power of the cartridge and reducing the impulse recoil, but at the same time this also influenced the decrease in the initial speed of the bullet. In a defensive battle, shooting was carried out at much longer ranges and mainly from stable positions, so the dispersion here is much less, and the decisive factor was the flatness of the trajectory and the penetrating effect, which could only be achieved by increasing the power of the cartridge. The contradiction between increasing the initial speed of the bullet and its mass and reducing these characteristics for different conditions The battle forced Soviet gunsmiths to look for the best option.

Therefore, in 1961 in the Soviet Union, specialists from NII-61 began comprehensive research to reduce the recoil impulse of weapons and develop a new 5.6-mm cartridge with a high initial velocity based on a recompressed cartridge case of a 7.62-mm automatic cartridge mod. 1943.

The first stage of research work, which began in the Soviet Union in 1963, to create a new “ammunition-weapon” complex was carried out on re-barrel AKM assault rifles of 5.6 mm caliber. As a result of the research, it turned out that the new 5.6 mm cartridge had a 35 percent lower recoil impulse than the 7.62 mm cartridge mod. 1943, and this made it possible to reduce the recoil energy of the weapon by 1.8 times. Research artillery test site of the USSR Ministry of Defense in the Vsevolozhsk region Leningrad region, analyzing the possibilities of using new, most optimal design schemes for small arms, indicated in his conclusion that “the most effective means improving the accuracy of an assault rifle when firing from unstable positions is to reduce the recoil impulse when firing.”

An important factor that contributed to this conclusion of our military experts was the fact that the AR 15 rifle was superior to the AKM assault rifle not only in one of the main parameters - combat accuracy, but also in the probability of hits. Thus, the most realistic way to increase 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 assault rifle for it.

As a result of long-term work by a group of specialists - ammunition specialists of TsNIITOCHMASH (Klimovsk, Moscow region) under the leadership of V. M. Sabelnikov, consisting of L. I. Bulavskaya, B. V. Semin, M. E. Fedorov, P. F. Sazonov, V. . I. Volkova, V. A. Nikolaeva, E. E. Zimina, P. S. Korolev and others created a completely new domestic 5.6-mm low-pulse cartridge with a bullet steel core and with a sleeve length of 39 mm, originally called “13 MZhV”. Subsequently, when the caliber designation was adopted, corresponding to the actual diameter of the barrel bore along the rifling fields - 5.45 mm, the cartridge received the GRAU index - 7 N6.

The designers managed to achieve an extremely low bullet weight (3.42 g instead of 7.9 g for the AKM and 3.56 g for the AR 15). permissible level recoil impulse of machine gun cartridges (0.49 kgf/s versus 0.78 and 0.58 kgf/s, respectively) and at the same time increase the range of a direct shot, i.e., the range at which the height of the trajectory is equal to the height of the target (440 m instead 350 and 426 m, respectively), which, by the way, exceeded the similar characteristics of the 7.62 mm rifle cartridge mod. 1908. The peculiarity of its bullet was that the steel core of the 5.45 mm 7 N6 cartridge had a lead jacket, and the bullet jacket was steel, clad with tombac. Such a design of the bullets ensured its better strength and greater penetrating effect than that of 5.56 x 45 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 as a sample from a single machine gun cartridge. It also had a void in the head, which, along with the optimally selected rifling pitch for this ammunition, provided the small-caliber bullet with the same mod. 1943 lethal effect over the entire direct shot range. Only by the end of the 1960s were the recommendations of V. G. Fedorov finally implemented, who 30 years earlier defended his point of view on the development of intermediate small-caliber cartridges.

Improving yourself mass type small arms of the Soviet army - Kalashnikov assault rifles - was largely determined by the successful development of new 5.45 mm machine gun cartridges. For firing from the AK 74 assault rifle, 5.45 mm low-pulse cartridges mod. 1974 with steel sleeves:
- with an ordinary bullet with a steel core (PS),

With a tracer bullet (T),
- with a bullet of reduced speed (SV).

To simulate shooting, blank cartridges were used (initially without a bullet, and later with a plastic bullet), automatic shooting which were carried out using a special bushing screwed onto the muzzle of the barrel, instead of a muzzle brake-compensator.

With an initial speed of 900 m/s of the AK 74 assault rifle, the bullet received a rotation speed of 4500 rpm, and the RPK 74 with an initial speed of 960 m/s - 4530 rpm). This ensured high stability of the bullet in flight, almost equivalent to the stability of a bullet from the 5.56 NATO cartridge (adopted for supply to the armies of the North Atlantic bloc only in 1980). To increase the destructive effect on manpower, the configuration of the bullet was selected 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 N6 with a flat trajectory made it possible to increase the range of a direct shot at a tall figure from 525 (for AKM) to 625 m (for AK 74). Sighting range firing from 5.45-mm machine guns was 1000 m. The effective firing range at ground targets from an assault rifle (compared to the AKM) increased to 500 m, from a machine gun - to 600 m; against airplanes, helicopters and paratroopers - from a machine gun and a machine gun - up to 500 m.

Concentrated fire on ground group targets can be carried out from machine guns and light machine guns at a distance of up to 1000 m. The direct shot range of the AK 74 assault rifle was: at the chest figure - 440 m, at the running figure - 625 m; for the RPK light machine gun 74–460 and 640 m (respectively).

However, in the AK 74 assault rifle, compared to the AKM, due to a decrease in caliber, the lethal range of the bullet was reduced from 1500 to 1350 m, i.e., the ratio between the lethal range and effective firing range decreased from 3.75 to 2.7 times. Dispersion when firing from an AK 74 in short bursts from stable positions (lying from a rest or standing from a trench) at a distance of up to 800 m began to be: the total median deviation of dispersion in height - 0.48 m, the total lateral deviation - 0.64 m. Reduction in mass cartridge allowed the soldier to increase his wearable ammunition from 100 rounds of 7.62 mm caliber to 165 rounds of 5.45 mm caliber without increasing the weight of the weapon. Increasing the initial bullet speed, flatness of the trajectory, and reducing the recoil impulse made it possible to increase the combat effectiveness of the 5.45 mm AK 74 assault rifle by 1.2–1.6 times compared to the 7.62 mm AKM assault rifle. A bullet with a steel core of the 7 N6 cartridge, when fired from an AK 74 assault rifle/RPK74 light machine gun, ensured penetration of a 5-mm steel sheet (with 80–90 percent of through penetration) at a range of 350 m, steel helmets(helmets) - at a distance of 800 m, standard domestic army body armor Zh86–5 - at 550 m.

However, work to improve the “ammunition-weapon” complex in the Soviet Union did not end there. New trends in military affairs, as well as the combat use of 5.45 mm Kalashnikov AK 74 assault rifles by the Soviet army in Afghanistan, led to the need to seriously modernize both the weapon itself and the 5.45 mm cartridge. The widespread use of personal armor (in particular, body armor) in the armies of many countries in the 1980s showed that their defeat when fired from machine guns is not guaranteed. Further development personal protective equipment, the use of body armor with plates made of durable titanium alloys sharply reduced the effectiveness of the 7 N6 bullet with a heat-strengthened core due to the imperfect shape of the core, which is not capable of piercing a titanium alloy plate even at close ranges. Therefore, Soviet gunsmith designers had to look for new ways to increase the penetrating effect of bullets from low-pulse machine gun cartridges. Already in 1986, the penetrating effect of 5.45 mm cartridges was significantly increased due to the use of a heat-strengthened core of increased hardness 7 N6 M in the bullet design: the penetration range of protected targets, in particular steel helmets, increased from 800 to 960 m, body armor with titanium plates from 20 to 200 m. Since the beginning of the 1990s, almost simultaneously with the adoption of the 5.45-mm modernized AK 74 M assault rifle (in 1991), cartridges with new bullets of increased penetration have also been introduced into service, complementing them together with a newly developed machine gun weapon system for the infantryman. So, in 1992, the core was improved again, making it more pointed and heavier. At the same initial speed, a bullet of increased penetration (PP) with a heat-strengthened core (index 7 N10) now ensured penetration of the standard domestic army body armor Zh85-T (with 40 percent of through penetrations) at a distance of 200 m, and heavy body armor Zh95-K - at range of 50 m, while a bullet with a steel core of the 5.45 mm 7 N6 M cartridge penetrated the Zh85-T body armor only at a range of 90 m, and penetration of the Zh95-K body armor was not ensured at all firing ranges. As a result, the 5.45-mm cartridge 7 N10 with a PP bullet came very close to the 7.62-mm rifle cartridge mod. 1908, and their effectiveness in breaking through barriers compared to the bullet of the 7 N6 cartridge increased 1.84 times. However, ensuring a given level of direct shot range and penetration required an increase in the power of the 5.45 mm cartridge, which in a certain way affected the increased recoil impulse and the fairly large dispersion of bullets when firing the AK 74. In addition, the adoption of a new cartridge with a bullet of increased penetrating action also had reverse side. The survivability of AK 74 M assault rifle barrels has sharply decreased when firing the new cartridge. Therefore, the designers had to carry out a number of research projects to increase the survivability of the barrel bore. It should be noted that the reserves of the 5.45 mm bullet in terms of increasing the effectiveness of hitting obstacles are far from being exhausted; work in this direction continues. For recent years new modifications of 5.45-mm machine gun cartridges were created and accepted for supply to the Russian Armed Forces: with an armor-piercing bullet BP (index 7 H22); with armor-piercing bullet BS (index 7 H24); cartridge with an armor-piercing tracer bullet (index 7 BT4); - modernized cartridge with a tracer bullet (index 7 T3 M); with a bullet of reduced ricocheting ability (index 5.45 PRS).
Currently, the Russian Armed Forces use the following main variants of 5.45 mm low-pulse machine gun cartridges.

5.45 mm automatic cartridge mod. 1974 with a bullet with a steel core PS (index 7 H6)

Military cartridges with bullets of all types are produced only with a bottle-shaped steel case coated with dark green varnish with a non-protruding flange and groove. The propellant charge is SFO33 spheroid powder, which has been replaced since 1989 by SSNf30/3.69 grade gunpowder.
A pointed bullet with a diameter of 5.65 mm, with an elongated head with a rear cone without a belt, consists of a stamped steel core (St10 steel) weighing 1.43 g; lead jacket and bimetallic (steel clad with tombak) shell. The lead jacket does not reach the end of the shell, and in the front of the bullet, between the inner surface of the head of the shell and the lead jacket, there is a 5 mm long cavity, which helps to shift the center of gravity of the bullet somewhat back, which reduces the stability of the bullet when it meets the target. The edges of the shell in the tail of the bullet are rolled up with support on the bottom of the core. The bullet is not painted. In all combat cartridges of 5.45 mm caliber, except for cartridges with PP bullets, red varnish is used to seal the junction of the bullet with the edge of the case muzzle and the joint of the primer, which does not have a distinctive color. Currently out of print.

5.45 mm automatic cartridge mod. 1974 with a bullet of increased penetration PP (index 7 H10)

In 1992, a new modification of the 5.45-mm automatic cartridge model was adopted. 1974 with a bullet of increased penetration PP, developed by a creative group of designers and technologists from the Barnaul Machine Tool Plant. The bullet with increased penetration PP received a stamped elongated steel heat-strengthened core of greater mass. The core, made of St70 steel (weighing 1.72 g) or St75 (weighing 1.8 g), has a head part of a more streamlined ogive shape, a flat top with a diameter of 1.8 mm and a recess in the center of the bottom (unlike the PS bullet) . The PP bullet with increased penetration ensured penetration of alloy plates at a distance of 100 meters - 100 percent and steel plates 14 mm thick at a distance of 100 meters of at least 80 percent.

5.45 mm machine gun cartridges mod. 1974 are sealed in standard wooden cartridge boxes of 2160 pieces each. Each box holds two metal roll-up boxes containing 1,080 rounds of ammunition. There is also a packaging option in which packs of cartridges are placed not in steel boxes, but in waterproof paper bags (120 rounds each), four packs of 30 rounds each. At the same time, the inscription “moisture-proof bags” is written on the wooden box. The closure contains special abbreviated alphanumeric designations. Boxes and crates containing cartridges with special bullets are additionally marked with a colored stripe corresponding to the distinctive coloring of the cartridge.

This cartridge owes its birth to the success of the American program to rearm its army with weapons chambered for a small-caliber cartridge (5.56x45 mm NATO). As a result, in the mid-1970s, the Soviet Army adopted a small arms complex consisting of a cartridge, an AK-74 assault rifle (AKS-74) and an RPK-74 light machine gun. Later, the shortened AKS-74U assault rifle joined this family. Currently, the assessment of this step (the transition from a 7.62 mm caliber to a 5.45 mm caliber) is quite ambiguous. On the one hand, there is a common myth about a bullet “with a displaced center of gravity,” which has significant destructive power due to the fact that after hitting the body, such a bullet supposedly begins to tumble and inflicts terrible wounds. There is more than one known case when people paid with their lives for excessive faith in this myth, trying to go out with military weapons (usually with an AK-74) to hunt a wild boar or bear. At the same time, they did not take into account both the great protection of these animals from light bullets (thick skin, a significant layer of fat and meat), and their enormous survivability. Yes, of course, 30 bullet hits with such a bullet can kill large bear. But this will happen, with a high probability, not quickly enough so that the bear does not have time to attack the unlucky shooter - after all, even a much more powerful cartridge - 7.62x54 mm - is recognized by experts as insufficient for bear hunting. By the way, bullets “with a displaced center of gravity” do not exist at all - there are simply bullets that, due to the barrel being cut too flat ( big step rifling) is given an insufficient rotation speed, which is why such a bullet has a small margin of dynamic stability and begins to precess (and, as a result, change trajectory) when it comes into contact with even minor obstacles.

On the other hand, in recent years there has been an opinion (not without taking into account the experience Afghan war and the latest local conflicts), that the lethal effect of the 5.45x39 mm cartridge is not enough in relation to humans either. Despite the fact that the transition to the 5.45 mm cartridge made it possible to improve shooting accuracy (by reducing recoil and increasing the direct shot range by almost 100 meters), many fighters operating in the Chechen conflict zone prefer the good old AKM 7.62 caliber mm due to their great penetration and destructive power. Supporters of the 5.45 mm cartridge argue that the problem is in the outdated 7N6 cartridge, and that with the new 7N10 (increased penetration) and 7N22 (armor-piercing) cartridges, 5.45 mm weapons are comparable in their combat characteristics to older models chambered for 7. 62x39 mm.

Performance characteristics of the cartridge (military 7N10, with a bullet of increased penetration)

The domestic 5.45x39 cartridge is a typical example of how the “arms race” stimulates the implementation of design solutions that are usually shelved. The idea of adopting a small-caliber cartridge with optimal ballistic characteristics as the main ammunition for small automatic weapons was proposed and justified at the beginning of the twentieth century, but found practical implementation only at the end of the last century.

We are, of course, talking about the works of the outstanding domestic designer V.G. Fedorov, who back in 1913 proposed his automatic rifle chambered for a reduced caliber 6.5 mm, and in the 1930-40s. comprehensively substantiated the advantages of small-caliber small-sized ammunition at effective firing ranges. For more than one decade, Fedorov consistently and persistently defended the ideas of small-caliber and then low-pulse ammunition, combining in his works not only a strong theoretical basis, but also rich practical material. However, for a number of reasons, including those of a purely technological nature, his work for a long time had no practical implementation until the notorious “arms race” factor came into play.

Intelligence reported accurately...

Intensification of work to justify the use of small-caliber cartridges for armament of the army began in the late 1950s. after receiving information from abroad about American experiences with the 5.56 mm AR-15 automatic rifle and the new Remington automatic cartridge. The history of the development of 5.56x45 ammunition and its adoption in 1962 for limited supply to the US Air Force has already been described in our magazine (No. 2, 2011). It is only worth adding to it that already in 1959, Soviet designers had at their disposal two experienced American cartridges (the future M193). The history of the creation of 5.45x39 began with them, which lasted almost 10 years. Such a long period of development and fine-tuning of such a “small” ammunition is explained by the fact that the designers had to find a middle ground among many conflicting requirements and parameters of a promising cartridge. Thus, to reduce dispersion and increase the probability of hitting a target, it was necessary to reduce the recoil impulse and power, but at the same time, to increase the penetration and lethality of a bullet, on the contrary, it was necessary to increase the power of the cartridge and the mass of the bullet. On top of that, the developments had to take into account a number of new calculated values, such as effective firing range and hit probability. To conduct comprehensive tests of the new American cartridge, a kind of “hybrid” was created from the domestic cartridge case “mod. 43 years old", re-compressed for experimental 5.6 mm bullets made according to the American model. Cal barrels were made for shooting. 5.6 mm with rifling of the same steepness as in American weapons. During comparative tests of experimental 5.6 mm cartridges with domestic 7.62 mm model 43, carried out at NII-61, high instability of cal bullets was revealed. 5.6 mm. This was due not only to the length and shape of the 3.56-gram M193 bullet, but also to the steepness of the rifling. Calculated data on the ballistic characteristics of the experimental bullet, its design, lethality and penetration ability also did not allow us to draw any clear conclusions. Work on studying the small-caliber cartridge continued, but with bullets of our own design. Initially, research focused on selecting the most effective form and bullet design, after which the characteristics of the recoil impulse of the cartridge and the DPV of the bullet were developed. In turn, this led to the development of a new type of gunpowder and the selection of its optimal weight, as well as a radical change in the dimensions of the cartridge case. To improve the aerodynamic characteristics of the bullet, its length was increased compared to the American one, and to maintain optimal weight, a steel core was introduced into its design (the presence of a steel core made it possible to further increase the bullet's penetration ability). A steel, tombac-clad (bimetallic) jacket was developed for the new bullet, which increased its strength characteristics compared to American bullets with a soft tombac jacket, which fragmented into many fragments after hitting an obstacle. As a result of the experiments, a bullet with a length of 25.55 mm and a mass of 3.4 g was developed, which received the symbol 5.45 PS.

New sleeve

At first, the 5.45-mm low-pulse cartridge used pyroxylin tubular powder of the VUfl 545 brand, but it was almost immediately replaced with varnish, the latest development grade Sf033fl (spheroid, thickness of the burning arch - 0.33 mm, phlegmatized) spherical graining with higher energy indicators and higher gravimetric density. The weight of the sample was chosen to be 1.44 g. Gunpowder brand VUfl 545 is currently used only for equipping 5.45 mm cartridges with bullets with reduced ricocheting ability - PRS. Initially, new bullets were loaded into recompressed bimetallic machine gun casings “model. 43 years", which by that time had already been mastered in the production of domestic sports and hunting cartridges 5.6x39 and were used in hunting carbine"Leopard".
An experimental batch of about 2 million units was sent for testing to the Odessa Military District. However, when working in automatic weapons, a number of shortcomings appeared in the design of the cartridge case with a large slope and a too “thick” body. The use of new Sf033fl gunpowder in the cartridge made it possible to reduce the diameter of the cartridge case body without losing the required characteristics of the ammunition. The design of the reduced sleeve was carried out by the engineer of the development group, Lidiya Ivanovna Bulavskaya. At the stage of final testing, the new compact ammunition received the conditional index of the developer (TsNIITOCHMASH, Klimovsk) - 13MZhV. After the final fine-tuning of the bullet, carried out by cartridge production technologist Mikhail Egorovich Fedorov, it was assigned a 5.45 mm caliber, measured according to the domestic standard - by field. For some time, the new cartridge was produced with bimetallic sleeves, but at the stage of final development of the cartridge by 1967, more economical varnished steel sleeves were developed. The actual length of the cartridge case was 39.82 mm, but in the currently accepted international designation for this ammunition, the length of the cartridge case is usually rounded to 39 mm. To equip the 5.45 mm cartridge cases, a brass KV-16 igniter capsule with a diameter of 5.06 mm was used, which later received the army index 7KV1. A large team of ammunition specialists under the leadership of V.M. took part in the creation of the new ammunition. Sabelnikova.

In parallel with the experiments on the ordinary one, work was carried out to create cartridges with special bullets - tracers and reduced speed. After testing the entire complex of the new small-caliber small arms The Soviet Army - machine guns and light machine guns - the 5.45x39 cartridge received the GRAU 7N6 index and was officially adopted into service in 1974, although its mass production began in the late 1960s. Simultaneously with the 7N6, ammunition with tracer bullets (index 7T3), cartridges with reduced bullet speed (index 7U1), blanks (index 7X3) and training (index 7X4) were accepted. The production of machine gun cartridges was launched at six Soviet cartridge factories - Ulyanovsk (No. 3), Amur (No. 7), Barnaul (No. 17), Frunzensky (No. 60), Lugansk (No. 270) and Tula (No. 539).

Standard bullet

The 7N6 cartridge was equipped with a PS bullet with a conical bottom part 25.55 mm long and weighing 3.4 g. The bullet consisted of a bimetallic shell, a lead jacket and a blunt core made of grade 10 steel. There is a technological cavity between the upper end of the core and the bullet shell. The charge of gunpowder Sf033fl (since 1987 - grade SSNf 30/3.69) gives the bullet an initial speed of the order of 870-890 m/s. Subsequently, due to an increase in the level of protection of targets by means personal protection(NIB), there was a need to strengthen the penetration ability of a conventional cal bullet. 5.45 mm, which was achieved through the use of a hardened core made of steel grades 65G, 70 or 75. A new modification of the 7N6M cartridge was adopted in 1987. The 7N6 and 7N6M cartridges do not have a special distinctive color marking. The subsequent appearance of body armor with titanium armor plates prompted the search for new ways to further increase the penetrating effect of bullets of the 5.45 mm cartridge. By 1991, specialists from the Lugansk Machine Tool Plant (No. 270) had developed a cartridge with a bullet of increased penetration (symbol of the 5.45 PP cartridge), which, after being put into service, received the GRAU 7N10 index. The bullet of the new cartridge received an elongated stamped hardened core made of steel grades 70 and 75 with a pointed top and a flat cut of the head with a diameter of about 1.8 mm. There was also a technological cavity in the head of the bullet. In addition to increasing the mass of the bullet to 3.6 g due to an increase in the length of the core, the mass of the powder charge was also slightly increased - up to 1.46 g. The new cartridge was adopted for service, but with the collapse of the USSR, the technological line for the production of 7N10 cartridges and the corresponding rights to development remained in Lugansk. In this situation, Russian producers urgently we had to “re-develop” the 7N10 cartridge, which later resulted in a number of upgrades to the 5.45x39 cartridge, which will be discussed in our next issue.

Tracer bullets

The second main cartridge of the 5.45 mm caliber ammunition was a cartridge with a tracer bullet, which was simultaneously developed at the very early stage of experiments with small-caliber cartridges. The bullet structurally consisted of a bimetallic shell, a lead core in the head and a tracer compound with a calibration ring in the bottom. Due to the small size of the bullet, the tracer compound was placed directly into the shell without a tracer cup. To improve the incendiary effect, the composition itself was made of two components - from the main tracer composition and the incendiary initiating it. Until 1976, bullets with a length of 26.45 mm and a mass of 3.36 g were produced, which were soon replaced by shorter ones with a length of 25.32 mm and a mass of 3.2 g. Reducing the length of the bullet, without significant damage to its characteristics, allowed several reduce the length of the cylindrical leading part, which, in turn, reduced wear on small arms barrels. The mass of the Sf0033fl powder charge was 1.41 g. The cartridge with a tracer bullet under the symbol 5.45 T and the GRAU 7T3 index was adopted for service in 1974. The distinctive marking of tracer ammunition was the coloring of the top of the bullet in green.

Reduced speed

Another standard 5.45 mm ammunition was a cartridge with a reduced bullet speed, which received the symbol 5.45US (cartridge index 7U1). It is designed for use with weapons equipped with a “silent and flameless firing device” - PBS. The experience of using the domestic 7.62-mm AKM assault rifle and the PBS-1 device in the military served as the basis for the development of a similar complex for the AK74 cal assault rifle. 5.45 mm. During the experimental work, we consistently worked out various types“silent” bullets together with different models of silent and flameless firing devices - first with PBS-2, then with PBS-3 and, finally, with the final version adopted for service - PBS-4. During development, the designers faced a number of problems technological and physical properties, related both to the ammunition itself and to the weapon used for it. Small caliber and dimensions of cal ammunition. The 5.45 mm made it very difficult to create a special cartridge with optimal characteristics. On the one hand, for satisfactory operation of the PBS, it was necessary to reduce the charge (to obtain a subsonic bullet speed) and increase the mass of the bullet (to increase its lethality), and on the other hand, it was necessary to increase the mass of the powder charge to increase the effective firing range. Moreover, the difference in the length of the barrels of AK74 assault rifles, RPK machine guns 74 and shortened AKS74U assault rifles made it almost impossible to create a “universal” cartridge that would work equally in all types. In addition, it was necessary to take into account the influence of the degree of wear of a small-caliber barrel on the ballistic characteristics of the bullet. With increasing wear, the initial speed of the bullet increased, and exceeding the subsonic speed negated the “subsonic” principle of sound dampening. As a result, a compromise decision was made - to test the US cartridge only for shortened AKS74U assault rifles with their subsequent modification for the improved PBS-4 device. This measure, in turn, limited the use of PBS-4 only to modified models of assault rifles and, accordingly, narrowed the general distribution of the complex only to some special forces of law enforcement agencies - the KGB, the Ministry of Internal Affairs and the USSR Ministry of Defense. The new machine gun with the designation AKS74UB was assigned the index GRAU 6P27. Additionally, the AKS74UB could be equipped with an under-barrel silent grenade launcher BS-1M with a 30-mm cumulative incendiary grenade 7P25. This rifle-grenade launcher complex (SGK) called “Canary” was assigned the GRAU 6S1 index. Throwing a 30-mm grenade was carried out using a special blank PHS cartridge supplied from an 8-round grenade launcher magazine. In parallel with the experiments on testing the PBS, there was a constant modernization of the US cartridge.

By the end of the 1970s, the first version of the cartridge was developed, consisting of an ordinary 7N6 bullet and a reduced powder charge. The cartridge had reinforced varnish at the junction of the bullet and the cartridge case and the top of the bullet was black. Then a special bullet with a lead core and a reduced ogive radius was developed for the US cartridge. The distinctive marking of the new US cartridge model was the coloring of the bullet tip with purple varnish. However, the mass of the new bullet turned out to be insufficient for full-fledged work PBS, and in addition to the lead core, an additional weighted core made of tungsten-cobalt alloy (grade VK8) was introduced into the design. To improve the obturation of the bullet in the barrel, its diameter was increased from 5.65 mm to 5.67 mm, which is why a characteristic ledge appeared on its ogive. The total length of the bullet after modification was 24.3 mm. P-125 pistol powder weighing 0.31 g was used as a propellant charge. The production of several batches of the final version of the 7U1 cartridge was launched in the late 1980s. at the Lugansk Machine Tool Plant.

Test cartridges

For testing weapons cal. 5.45 mm VD cartridges were developed ( high pressure) and ultrasonic (reinforced charge). VD (index GRAU 7Shch3) is designed to test the strength of weapon barrels in factory conditions. This cartridge is equipped with a bullet with a steel core weighing 3.5 g and a powder charge increased to 1.52 g. The VD bullet has an enlarged leading part due to the lack of a rear cone, like a conventional PS. Distinctive marking of the VD cartridge - bullet color yellow. The cartridge with the UZ bullet is designed to test the strength of weapon locking units. As its name suggests, it has a charge of SSNf 30/3.69 gunpowder reinforced to 1.46 g. The cartridge, which received the GRAU 7Shch4 index, is equipped with a conventional PS bullet with a steel core. The distinctive marking of the UZ cartridge is a black bullet.
Model cartridges are intended for certification of ballistic weapons, testing new samples of cartridges and conducting control measurements during shooting. Sample cartridges are made from components of gross cartridges selected during mass production according to more stringent requirements for quality and geometric parameters. Exemplary cartridges have a distinctive marking in the form of a bullet tip, painted white.

Soviet Minimi
In the second half of the twentieth century. The idea of creating a machine gun with a combined feed: from a belt and a magazine, received practical development. This concept was implemented in the Belgian FN Minimi/M249 machine gun, the Israeli Negev and the Czech Vz.52/57. In the USSR, similar developments began in the fall of 1971 at the Izhevsk Machine-Building Plant. The objective of the project, called PU (machine gun with a unified feed), was to develop a belt-fed machine gun based on the standard RPK-74 with the additional ability to use magazine feed and increase the efficiency of the base model by one and a half times. Well-known design engineers took part in the work: Yu.K. Alexandrov, V.M. Kalashnikov, M.E. Dragunov, A.I. Nesterov. The drawings of the first prototype were ready in 1973, and in the spring of 1974, preliminary tests of the first model of the experimental PU machine gun were carried out at the Izhmash training ground. In the same year, the prototype was transferred to TsNIITOCHMASH for testing. The development was called “Poplin”. In the course of subsequent work, several models of machine guns with belt-magazine feed were developed, which were tested at TsNIITOCHMASH and at the training ground of the Ministry of Defense. Several versions of metal belts with a capacity of 200 rounds were developed for experimental machine guns. The tape was placed in a duralumin box, which was attached from below to the receiver. The machine gun was developed for standard magazines from the RPK-74 and AK-74, but in the course of work on the “Poplin” theme, high-capacity magazines were developed - a disk magazine for 100 rounds (designer V.V. Kamzolov) and a drum MZO (designer V.N. Paranin). The last experimental model of the machine gun was assembled in 1978, but the topic was soon closed. According to the military, belt feeding, along with increasing the combat rate of fire, still increases the weight and dimensions of machine guns. Options for machine guns with combined power supply have a complex design of the feed unit and reduced reliability due to differences in the amount of energy required for reloading with belt and magazine power. Later, based on the results of the “Poplin” theme, a removable SPU tape feeder was developed, which made it possible to use belt feed for standard RPK machine guns and AK assault rifles. The SPU consisted of a metal belt, a box and a tape feed mechanism driven by the bolt frame. However, this development was also not developed due to the complexity of the design and the large amount of adjustment of components.

Single and training

At the end of the 1970s. to simulate the sound of a shot when firing from a standard cal. 5.45-mm designers TsNII TOC MASH V.I. Volkov and B.A. Johansen developed a blank cartridge. At the experimental stage, a blank cartridge with an elongated barrel compressed by a star was tested. However, subsequently preference was given to cartridges with a conventional sleeve and a plastic hollow bullet white. This cartridge was adopted for service under the designation GRAU 7X3. A blank cartridge is used together with a special muzzle sleeve, which provides the required level of pressure of the powder gases when fired and guaranteed destruction of the plastic “bullet”. Until the 1980s sealant varnish was applied to the junction of the cartridge case and the blank cartridge bullet purple, later they began to use red varnish.
In the 1970s to teach the rules of handling weapons, a 5.45 mm training cartridge was developed (GRAU index 7X4). This ammunition, developed by TsNIITOCHMASH designer V.I. Volkov, consists of a standard cartridge case with a cooled primer and a regular PS bullet. The training ammunition has reinforced bullet retention in the cartridge case and four longitudinal grooves on the case body. No sealant varnish or distinctive color markings were applied to the training cartridge.
IN Soviet period nomenclature of cartridges cal. The 5.45 mm was much more modest compared to the 7.62 mm cartridge mod. 43 years old. This caliber did not have cartridges with incendiary and armor-piercing incendiary bullets. This was due to the small internal volume of the bullet, which did not allow the placement of “oversized” elements of incendiary systems and any effective amount of initiating compounds.

5.6x45 "Biathlon"
A separate bright episode in national history small-caliber intermediate ammunition flashed a 5.6-mm sports cartridge "Biathlon". Since the mid-1960s. In parallel with the development of the 5.45-mm machine gun cartridge, work began in the USSR on the creation of small-caliber sports ammunition and a sports rifle. As in the case of the 5.45-mm automatic cartridge, the case of the 7.62-mm automatic cartridge “model. 43 years old." But, unlike military ammunition, the casing of the sports cartridge was immediately made of brass, which is the norm for sports cartridges. The result was a fairly powerful ammunition with a sleeve 45 mm long, allowing for a fairly large powder charge, and a bullet 25.0 mm long and weighing 4.93 g. The capsule had reinforced fixation using triple point punching. Using the new cartridge, Izhevsk designers Anisimov and Susloparov developed the world's first “biathlon” rifle BI-5 with fast reloading and low recoil impulse. The release of new cartridges was carried out in small experimental batches in the late 1960s - early 1970s. Small-scale production of BI-5 rifles was established in 1973-1975. in the experimental workshop of Izhmash. At first, the cartridge and rifle were tested at intra-Union biathlon competitions, and in 1976, during the Winter Olympic Games The world premiere took place in Innsbruck, Austria. The result exceeded all expectations: all the gold went to the Soviet team. N. Kruglov became Olympic champion in the 20 km race, and the USSR national team became the Olympic champion in the relay. New Soviet cartridge created a real sensation, because at that time, even standard 5.45-mm machine gun ammunition was a sealed secret for Europe, and what can we say about highly specialized sports ammunition. A year later, the biathlon world said goodbye to powerful cartridges: in 1977 at the Congress International Federation pentathlon and biathlon, new rules were adopted, according to which, from 1978, the standard cartridge for biathlon became .22 Long Rifle, and the distance to the target was reduced to 50 m.
The farewell of Soviet biathletes to a promising rifle took place in 1977 in the Norwegian city of Wingrom. The main hero of the sprint race was the outstanding Soviet biathlete Alexander Ivanovich Tikhonov. Without making a single mistake, leaving far behind all competitors, at the final stage of the race the athlete took the rifle off his shoulder, raised it above his head and thus covered the last 300-400 meters of the distance. At the finish line, he defiantly threw his weapon into the snow, never to pick it up again. According to eyewitnesses, the King of Norway, who was present at these competitions, could hardly hold back his tears - the scene was so poignant. This is how Tikhonov won his last, 11th, gold medal, and thus ended the career of the domestic 5.6x45 Biathlon sports cartridge. The following year, the World Championship was held in Hochfilzen, Austria, but under new rules and with new cartridges. Our team returned from there without a single award.

To make it easier to equip stores with cartridges, special fast-charging clips (index 6Yu20.6) for 15 rounds were adopted. It was assumed that in conditions close to combat, a serviceman would be able to have spare ammunition, pre-loaded into clips for quickly loading stores during battle. The clip is fixed to the neck of the magazine using a special Y-shaped adapter (Index 6Yu20.7). When developing the clip, other options were tested, both with and without an adapter.

Container and marking

The packing capacity of 5.45 mm cartridges was a multiple of the capacity of a standard 30-round machine gun magazine. Initially, cartridges were packaged in 30-round cardboard boxes, but in the mid-70s the decision was made to switch to a simplified paper wrapper, secured with two staples. 36 paper bags with a total of 1,080 cartridges were placed in a welded metal box. Two metal boxes fit into a standard wooden box for 2,160 rounds of ammunition. A stencil was applied to the lid of the box indicating the basic data of the ammunition. In parallel with packing cartridges in paper wrappers into metal boxes, the practice was to pack 4 paper packs of 30 rounds into moisture-proof bags for 120 rounds and place these bags in a wooden box without metal boxes. With this packaging, the wooden box also contained 2,160 rounds of ammunition. Distinctive feature ammunition intended for sealing in moisture-proof bags, there was a protective oxidized coating of the primer in black, which was canceled as mandatory in 1988. For cartridges with special bullets, it is typical to apply the corresponding color stripes over stenciled inscriptions on all types of containers: paper wrappers, metal boxes and wooden boxes. For cartridges with tracer bullets, color marking is adopted in the form of a green stripe, and for cartridges with reduced bullet speed - in the form of a black and green stripe. Unusual feature, which has not yet found a documented explanation, is the system symbols on the closure of 5.45 mm live cartridges produced before 1982, which differed from the standard design adopted for small arms ammunition Soviet Army. According to the “traditional” system of symbols, the closure with cartridges must be sequentially marked with the caliber of the cartridge, the type of its bullet (PS, T or US) and then the type of cartridge case used (GZh - bimetallic, GS - varnished steel). For some reason, until 1982, on all types of containers of 5.45 mm cartridges, after the caliber designation, the designation of the cartridge type was applied, and only after it - the designation of the bullet type, for example, 5.45gsPS instead of 5.45PSgs.

The legend of the "center of gravity"
It is worth noting that the unusually small cartridge was received ambiguously by weapons specialists and the military. “Grandfather of Soviet machine guns” M.T. Kalashnikov was categorically against the new ammunition, arguing that for a small and long bullet, or “punch,” as Mikhail Timofeevich dubbed it at one of the ministerial meetings, it would not be possible to work out the survivability of the barrel. Indeed, initially the barrels of experimental machine guns could withstand about 2,000 shots, while the military demanded at least 10,000. It took the efforts of a separate institute, NII-13, and weapons production specialists in Kovrov and Izhevsk to solve this problem and achieve standard resource barrels of 12,000 rounds. A characteristic feature of the 5.45 mm ammunition is the sudden loss of stability of the bullet when it hits an obstacle. The Internet resource YouTube posted an interesting video in which Americans almost point-blank are trying to shoot a TV screen at an angle with an AK-74, but the bullets ricochet off its surface and cannot break it. This property of a bullet - to sharply change its flight path when meeting an obstacle - gave rise to a persistent legend among the people (and even in the army) about a “bullet with a displaced center of gravity.” In fact, the center of gravity of the bullet, of course, lies on its longitudinal axis of symmetry (closer to the bottom) and does not “shift” anywhere. It’s just that a set of indicators such as the length and mass of the bullet, the position of its center of gravity, the ratio of the moments of inertia and the pitch of the barrel rifling are selected so that the bullet during flight is at the limit of gyroscopic stability. When hitting an obstacle, the action of two forces - gravity and the force of resistance to the environment - creates a tipping moment, at which light small-caliber bullets lose stability and turn around. This property of the bullet causes certain inconveniences when shooting “on TV”, but leads to serious injuries when hitting living targets.

Stores

The AK-74 assault rifle was fed from a box-shaped sector magazine (index 6L23) with a capacity of 30 rounds, made of orange AG-4V fiberglass. For the RPK-74 light machine guns, high-capacity box-shaped sector magazines with 45 rounds (index 6L18) were developed, which were also made from AG-4V fiberglass. Since the 1980s magazines for 30 rounds and new improved magazines for 45 rounds (index 6L26) began to be made from glass-filled polyamide PA-6 of a dark purple color, which received the nickname “plum” in the army. Since the 1970s, with to varying degrees Intensity, experimental work was carried out to further increase the capacity of cartridge magazines. Options were tested for creating steel 60-round magazines with a 4-row arrangement of cartridges, followed by the restructuring of the cartridges at the neck into a standard 2-row feed. However, the practical implementation of these works took place only by 2000, when the Russian Federation a high-capacity magazine (RF Patent No. 2158890) made of black plastic was adopted.