Military history, weapons, old and military maps. Russian cartridges Cartridge 5.45 with offset center

Bullets with a shifted center of gravity: reality and myths September 19th, 2016

Bullets with a shifted center of gravity are known to any person more or less knowledgeable about weapons. Various legends are associated with them, the essence of which boils down to the following: when it hits the body, a bullet with a displaced center of gravity begins to move along a chaotic trajectory; Having hit, for example, the leg, such a miracle bullet can come out of the head. All this is often told in all seriousness.

Do off-center bullets really exist and are they capable of causing such injuries? Let's try to figure it out.

What are bullets with a shifted center of gravity?

The answer to the question about the existence of bullets with a shifted center of gravity is beyond doubt. Such bullets really exist, and have been for quite some time. Their history began in 1903-1905, when instead of the previous blunt-pointed rifle bullets, two types of pointed bullets were adopted: heavy ones for long-range fire and light ones for short-range fire. These bullets had improved aerodynamics compared to blunt-point ones. They entered service with the armies of the leading powers of the world almost at the same time, and in Germany, the USA, Turkey and Russia light bullets were first adopted, and in England, France and Japan - heavy ones.

Types of bullets Types of bullets: A - blunt-pointed, B - heavy-pointed, C - light-pointed. The squares indicate the center of gravity, the circles indicate the center of air resistance.

Light bullets, in addition to improved aerodynamics, had a number of other advantages. The lower mass of the bullet, taking into account the colossal volumes of manufactured ammunition, provided significant savings in metal. The shooter's wearable ammunition was also increased. The light bullet had a higher initial speed (compared to the blunt-pointed one - by 100-200 m/s), which, together with its improved ballistics, increased the range of a direct shot. Experience in combat operations at the end of the 19th - beginning of the 20th centuries. showed that ranges up to 300-400 m are the maximum for conducting aimed shooting averagely trained fighter. The introduction of light bullets made it possible to increase the effectiveness of aimed fire at the specified ranges, with the same training of shooters. The advantages of heavy bullets at close ranges were excessive. They were needed only for long-range machine-gun and rifle fire.

Experience practical application light pointed bullets revealed one not very pleasant feature of them. They fired from rifles designed to fire blunt bullets. The barrels of such rifles had gentle rifling, which was enough to stabilize blunt-pointed bullets, but light bullets fired from them turned out to be unstable in flight due to insufficient rotation speed. As a result, the accuracy and penetration ability of light bullets decreased, and their drift under the influence of side winds increased. To stabilize the bullet in flight, its center of gravity began to be artificially moved back, closer to the bottom. To do this, the nose of the bullet was specially lightened by placing some lightweight material there: aluminum, fiber or pressed cotton pulp. But the Japanese acted most rationally. They made bullets with a jacket that was thicker at the front. Thus, two problems were solved at once: the center of gravity of the bullet shifted backwards, since specific gravity less shell material than lead; at the same time, due to the thickening of the shell, the bullet’s penetration ability increased. These were the first bullets with a shifted center of gravity.

As you can see, the shift in the center of gravity of the bullet was not done for its chaotic movement when it hit the body, but, on the contrary, for better stabilization. According to eyewitnesses, such bullets, when they hit tissue, left fairly neat wounds.

The nature of wounds from bullets with a displaced center of gravity

So what caused the rumors about terrible wounds inflicted by bullets with a displaced center of gravity? And how true are they?

Wound channel from M-193 bullet

For the first time, incomprehensibly extensive (relatively small-caliber bullet) wounds were noticed in relation to the .280 Ross cartridge of 7 mm caliber. However, the reason for them, as it turned out, was the high initial speed of the bullet - about 980 m/s. When such a bullet hits the body, high speed tissue located near the wound channel found itself in the water hammer zone. This led to the destruction of nearby internal organs and even bones.

Even more severe damage was caused by M-193 bullets, which were used to equip 5.56x45 cartridges for M-16 rifles. These bullets, with an initial speed of about 1000 m/s, also have the property of a hydrodynamic impact, but the severity of the wounds is not only explained by this. When such a bullet enters the body, it passes 10-12 cm in soft tissues, then unfolds, flattens and breaks in the area of ​​the annular groove intended for seating the bullet in the cartridge case. The bullet itself continues to move with its bottom forward, while many small fragments of the bullet formed during breaking strike tissue at a depth of up to 7 cm from the wound channel. Thus, tissues are affected by the combined effects of fragments and hydraulic shock. As a result, holes in the internal organs from bullets of such a seemingly small caliber can reach 5-7 cm in diameter.

At first it was believed that the reason for this behavior of the M-193 bullets was instability in flight due to the too shallow rifling of the M-16 rifle barrel (pitch - 305 mm). However, when a heavy M855 bullet was developed for the 5.56x45 cartridge, designed for steeper rifling (178 mm), the situation did not change. The increased rotation speed made it possible to stabilize the bullet, but the nature of the wounds remained the same.

Based on the above, the conclusion suggests itself that the displacement of the center of gravity of the bullet in itself in this case does not in any way affect the nature of the wounds it inflicts. The severity of the damage is explained by the speed of the bullet and some other factors.

5.45x39 ammunition - the Soviet answer to NATO

It turns out that everything they say about the properties of bullets with a shifted center of gravity is fiction? Not really.

Following the adoption of the 5.56x45 cartridge into service by the armies of NATO countries Soviet Union developed his own intermediate cartridge of a reduced caliber - 5.45x39. His bullet had a deliberately rearward center of gravity due to a cavity in the nose. This ammunition, designated 7N6, underwent a “baptism of fire” in Afghanistan. And here it turned out that the nature of the wounds inflicted by it was seriously different from the same M-193 and M855.

Ammunition 5.45x39

When it hit tissue, the Soviet bullet did not turn over with its tail forward, like small-caliber American bullets - it began to tumble randomly, turning over repeatedly as it moved in the wound channel. Unlike American bullets, 7N6 did not collapse, since its durable steel shell withstood hydraulic loads when moving inside the body.

Experts believe that one of the reasons for the behavior of the 7N6 ammunition bullet in soft tissues is the shifted center of gravity. When it hits the body, the rotation of the bullet slows down sharply, and the stabilizing factor ceases to play its role. Further tumbling occurs, apparently, as a result of processes occurring inside the bullet itself. The part of the lead jacket located closer to the bow shifts forward due to sharp braking, which leads to an additional shift in the center of gravity, and accordingly, the point of application of forces already during the movement of the bullet in the tissues. In addition, the bullet nose itself bends.

Taking into account the heterogeneity of the tissue structure, we get a very complex nature of the wounds inflicted by such bullets. The most severe tissue damage from 7N6 ammunition bullets occurs at the final stage of movement at a depth of more than 30 cm.

Now about the cases of “got in the leg - went out in the head.” If you look at the diagram of the wound channel, you will indeed notice some of its curvature. Obviously, the entry and exit holes from the bullet in this case will not strictly correspond to each other. But the deviation of the trajectory of the 7N6 ammunition bullet from a straight line begins only at a depth of 7 cm when it hits the tissue. The trajectory curve is noticeable only with a long wound channel, while at the same time, with edge hits, the damage caused is minimal.

Theoretically, given the increased tendency of the 7N6 ammunition bullet to ricochet, it is also possible sudden change its trajectory when it hits the bone tangentially. But, of course, if such a bullet hits the leg, it still won’t leave the head, for example. She simply does not have enough energy for this. When shooting at ballistic gelatin at point-blank range, the depth of penetration of the bullet does not exceed half a meter.

About ricochets

There is an opinion, typical of military personnel who have shot a lot in practice, about the increased tendency for bullets with a displaced center of gravity to ricochet. Examples are given of ricocheting from branches, from water and window glass when hit at sharp angles, or multiple reflections of a bullet when shooting in confined spaces with stone walls. However, the shifted center of gravity does not play any role in this.

Wound channel from a 5.45x39 ammunition bullet

First of all, there is general pattern- heavy, blunt-pointed bullets are least susceptible to ricochet. It is clear that 5.45x39 ammunition bullets are not classified as such. At the same time, at acute meeting angles, the impulse transmitted to the obstacle can be very small, insufficient to destroy it. There are known cases of even lead shot ricocheting off water, which for obvious reasons cannot have any shifted center of gravity.

As for reflection from the walls of the room, it is true that bullets from the M193 cartridge are less susceptible to it than bullets from the 7N6 ammunition. But this should only be attributed to the lower mechanical strength of American bullets. When they encounter an obstacle, they simply become more deformed and lose energy.

conclusions

Based on the above, several conclusions can be drawn.

Firstly, bullets with a shifted center of gravity do exist, and they are not some secret or prohibited type of ammunition. These are standard Soviet 5.45x39 ammunition bullets. Stories about some specially placed “rolling balls” and the like are nothing more than fiction.

Secondly, the shift of the center of gravity back was undertaken to increase flight stability, and not vice versa, as many people think. It would be correct to say that a displaced center of gravity is general property of all small-caliber pointed high-velocity bullets, resulting from their design.

Third, in relation to bullets of the 7N6 cartridge, the shift in the center of gravity really affects the behavior of the bullet in tissue. In this case, the bullet begins to tumble randomly, and its trajectory deviates from a straight line as it deepens into the tissue. This behavior of the bullet significantly increases the traumatic effect when hitting unarmored living targets.

However, there are no miracles like “hit in the shoulder, came out through the heel” and cannot be. This by-effect from the use of small-caliber high-speed bullets with a durable shell, and not a specially designed characteristic. The role of a displaced center of gravity in the infliction of complex atypical wounds by such bullets and increased ricocheting is greatly overestimated by public opinion.

sources

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 collectively have a large set 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.

Trend...
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 taken seriously in the United States, which they adopted for service in the mid-1960s. assault rifle M16A1. As soon as practical experience 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 weight 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 adopt more perfect complex weapons chambered for a 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 has become the AK-74M assault rifle, which has been entering service with the Russian army since the early 1990s. This machine gun 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 by 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.
"Pros and cons"
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 longer, 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 that of the 7.62 mm caliber, the flight path is more influenced by various kinds of obstacles and weather conditions, which must be taken into account when using weapons in the mountains, in the greenery.
7.62mm bullets are correspondingly heavier and have a larger cross-sectional area. This (primarily the mass) gives an advantage during combat operations in forest and mountainous areas, under adverse 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 the powder charge is larger and the recoil 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 its head 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. Much work was carried out at 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 specialists 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 it comes to 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 gunsmiths and scientists: at present, the 5.45 mm cartridge remains the best choice for individual automatic small arms. Further modernization of this ammunition will allow it to continue to successfully compete with foreign analogues.

1. 5.45x39 7N6; 2. 5.45x39 7N24; 3. 5.45x39 7N10; 4. 5.45x39 7N22

A low-impulse intermediate cartridge, developed in the early 70s by a group of Soviet designers as a counterweight to the American 5.56x34.5 cartridge (.223 Remington), which the Americans widely used in Vietnam in the 60s. By the beginning of the 70s, Soviet designers also realized the promise of intermediate small-caliber cartridges. A small-caliber bullet, having a high initial velocity, provides a highly flat trajectory, has good armor penetration and significant destructive power. At the end of the 50s, news reached the Union about tests in the United States of a new small-caliber automatic rifle M16. As was usual then, along with the news the rifle itself appeared. Legend has it that a hybrid consisting of a Kalashnikov assault rifle, an M16 barrel and a newly designed magazine was tested. The tests served as an impetus for the development of our own program to create a small-caliber assault rifle. The American barrel had a caliber of 22 or 5.56 mm, which corresponded to our small-caliber cartridge known as 5.6 mm. Thus began - rather as a tribute to fashion, rather than an urgent need - the development of a domestic 5.6 mm assault rifle. Again, the legend says that in Podolsk a number of American-style cartridges were manufactured for testing, which were quickly abandoned and they began to design their own ammunition with a bullet of the same diameter. They did something, but remembered that the USA has adopted a different system for measuring the caliber of weapons. Here they measure by the fields of the rifling, and overseas, as a rule, by the rifling themselves. With the same caliber designation, our bullets are thicker than American bullets by the depth of the rifling. So in the early 70s their .22 caliber with a bullet diameter of 5.56 mm turned into our 5.45 mm. There is nothing criminal in this practice of reasonable borrowing: the same Americans, having received our cartridge, albeit without a barrel, and having tested it to the fullest, came to the conclusion that it is superior to theirs. They immediately made a somewhat analogue of our XM777 bullet, replacing the lead core with a steel one. In the 80s, to replace the American M193 cartridge with a lead-core bullet, which was in service with NATO countries, the Belgian SS109 ammunition with a steel-core bullet was nevertheless adopted. To hit protected targets, the P112 cartridge with an armor-piercing bullet was adopted along with the SS109. A 5.45-mm automatic cartridge with a 7N6 steel core bullet and a 7T3 tracer bullet was developed under the leadership of V. M. Sabelnikov, a group of designers and technologists consisting of L. I. Bulavskaya, B. V. Semin, M. E. Fedorov, P. F. Sazonov, V. I. Volkov, V. A. Nikolaev, E. E. Zimin, P.S. Korolev and others. The 5.45-mm cartridge bullet is designed “on the verge of stability,” that is, it flies steadily in the air and begins to “tumble” when it hits a denser environment - living tissue, wood etc. This is achieved by shifting the center of gravity to the bottom of the bullet. To ensure that the bullet loses stability in a dense environment, the bullet core is located in the bullet jacket with a gap in the front of the bullet. There is a void in front of the core and jacket in the front part, which ensures a shift in the center of gravity of the bullet and instability in a medium dense compared to air. Types of cartridges 5.45 x 39:

"PS" - with a bullet with a steel core (index 7N6, 7N6VK) weighing 3.30-3.55 g. Since 1986, they have been produced with a heat-strengthened (up to 60 HRC) steel (65G) cylindrical core. The bullet is unpainted. "T" - tracer (7T3). Green bullet top. Cartridge for firing weapons with instruments silent shooting(index 7U1) contains a bullet weighing 5.15 g, which has an initial speed of 303 m/s. The coloring is a black bullet top with a green rim. Blank (7X3) with a plastic bullet weighing 0.22-0.26 g. Has a charge of special fast-burning gunpowder weighing 0.24 g. Training (without charge). It is distinguished by the presence of four longitudinal stampings on the cartridge case and a double circular crimp of the bullet in the cartridge case. In 1993, a PP cartridge (7N10) was released with a stamped core made of special grades of alloys such as steel 70 or 75 (a bullet with increased penetration), a bullet weighing 3.49-3.74 g penetrates a 16-mm steel plate, elements at a distance of 100 meters body armor made of titanium alloys at a distance of 200 meters. The sealant varnish is dark purple in color, in contrast to the red in 7N6. A stamped, pointed core is used that has a short ogive, and the nose of the core has a flat area with a diameter of about 0.8 mm. In 1994, a cartridge with a modernized 7N10 bullet of increased power was developed and put into production, the main difference of which is that the cavity in the nose is filled with lead, which prevented the shell from being pulled into the hole punched in the barrier by the core. Upon contact with an obstacle by the pressure of lead compressed between the head of the core and the bullet shell, the latter is destroyed. This device prevents parts of the shell from being pulled into the hole, which increases the bullet's penetration ability. In 1998, the BP (7N22) cartridge with an armor-piercing bullet weighing 3.68 g was developed and adopted for service, which penetrates an armor plate 5 mm thick at a distance of 250 meters. The 7N22 bullet uses a pointed core made of high carbon steel U12A, by cutting method with subsequent grinding of the ogive part. The sealant varnish is red, the bullet has a black nose. FSUE PO Vympel (Amursk) produces the 7N24 cartridge with an armor-piercing bullet weighing from 3.93 to 4.27 g and a speed of 840 m/s (data from the manufacturer’s website). Model cartridge - intended for comparative testing of the ballistic characteristics of cartridges stored in warehouses. Corresponds to the standard cartridge (7N6), but is manufactured with increased accuracy. The bullet nose is painted white. A cartridge with an enhanced charge (US) - the entire bullet is completely black. Cartridge high pressure(VD) - the entire bullet is entirely yellow. Cartridge 5.45x39 (5.45x40) SN-P for the SONAZ TP-82 complex. The bullet initially had a lead core and an exposed shell in the head, later - a steel core and a hole in the head. Bullet weight 3.6 g, initial speed - 825-840 m/s.

1. 5.45x39 7T3; 2. 5.45x39 7x3

Main technical characteristics of 5.45 mm bullets

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 did not have practical implementation for a long time, until the notorious “arms race” factor came into play.

Intelligence reported accurately...

Intensification of work to justify the use of small-caliber cartridges for arming 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 this, 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 to 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 a target. 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-impulse cartridge used pyroxylin tubular powder of the VUfl 545 brand, but it was almost immediately replaced by varnish, the latest development of the Sf033fl brand (spheroid, burning arch thickness - 0.33 mm, phlegmatized) spherical graining with more high energy indicators and greater 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 re-compressed 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 the Bars hunting carbine.
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 development, 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-pointed 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, in connection with the increase in the level of target protection with personal protective equipment (PPE), the need arose to enhance 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 bullet mass to 3.6 g by increasing the length of the core, the mass was also slightly increased powder charge- up to 1.46 g. The new cartridge was adopted for service, but with the collapse of the USSR technological line for the production of 7N10 cartridges and the corresponding development rights remained in Lugansk. In this situation, Russian manufacturers urgently 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 that initiates it. Until 1976, bullets with a length of 26.45 mm and a weight of 3.36 g were produced, which were soon replaced by shorter ones with a length of 25.32 mm and a weight 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 shooting 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. At the same time, the difference in the length of the barrels of AK74 assault rifles, RPK74 machine guns and shortened AKS74U assault rifles made it almost impossible to create a “universal” cartridge that would work equally in all samples. 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 to only modified models of assault rifles and, accordingly, narrowed the overall 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 the full operation of the 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 cartridges were developed for high pressure (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 absence 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 from serial production 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 A violet sealant varnish was applied to the junction of the cartridge case and the blank cartridge bullet; later, red varnish was used.
In the 1970s to teach the rules of handling weapons, a 5.45-mm training cartridge (GRAU index 7X4) was developed. This ammunition, developed by TsNIITOCHMASH designer V.I. Volkov, consists of a standard cartridge case with a cooled primer and a regular PS bullet. Training ammunition has reinforced bullet fixation in the case muzzle and four longitudinal grooves on the case body. Sealant varnish and distinctive color markings were not 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. 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 striking episode in the domestic history of small-caliber intermediate ammunition flashed by the 5.6-mm Biathlon sports cartridge. 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 cartridge case of the 7.62-mm automatic cartridge “model. 43 years". 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 45 mm long sleeve, allowing for a fairly large powder charge, and a 25.0 mm long bullet 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 the 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 all competitors far behind, 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 magazine neck 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 rounds of ammunition 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. A distinctive feature of ammunition intended for sealing in moisture-proof bags was the protective oxidized coating of the primer in black, which was abolished 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. An unusual feature that has not yet found a documentary explanation is the system of symbols on the closure of 5.45 mm live cartridges produced before 1982, which differed from standard scheme, adopted for small arms ammunition of the 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 a standard barrel life of 12,000 shots. 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.

The shops

The AK-74 assault rifle was powered from a box-shaped sector magazine (index 6L23) with a capacity of 30 rounds, made of AG-4V fiberglass orange color. For 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, experimental work has been carried out with varying degrees of intensity 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 a high-capacity magazine (RF Patent No. 2158890) made of black plastic was adopted into service with the law enforcement agencies of the Russian Federation.

Jun 26, 2014 Andrey aka Pulkin Donets and Dmitry aka Treshkin Adeev official IAA members

Research conducted in the USSR in the early 1960s showed that the accuracy of fire from a machine gun is determined mainly by the momentum of the cartridge and the recoil energy of the weapon. It was found that the most realistic way to increase the efficiency of shooting from individual weapons may be to adopt a new cartridge with a reduced impulse and develop a next-generation assault rifle for it.

Work on the creation of automatic 5.45-mm cartridges was carried out at the Central Research Institute of Precision Engineering together with the Design Bureau of Automatic Lines, the Tula Cartridge Plant and organizations of the Ministry of Defense.

The development of 5.45 mm cartridges was carried out taking into account the norms of International Humanitarian Law. At the same time, sufficient stability of the bullet along the trajectory and high lethality were ensured.

An increase in the initial bullet speed from 725 m/s (AKM) to 900 m/s (AK74) led to a significant improvement in the flatness of fire (increasing the direct shot range) from the new weapon. Less flight time, when shooting at the same range, helped to reduce shooting errors at moving targets and in crosswinds. A smaller recoil impulse ensured better accuracy of automatic fire. All this ensured an increase in the probability of hitting the target. Reducing the mass of the cartridge made it possible, with the same weight of portable ammunition, to increase it by 1.5 times.

In 1974, simultaneously with the AK-74 assault rifle, 5.45 mm cartridges with ordinary (steel core) and tracer bullets were adopted. In addition to live ammunition, blank and training cartridges were developed. Improvements to the 5.45 mm cartridge were carried out in the 1990s and early 2000s in the direction of increasing penetration (for a bullet with a steel core), as well as increasing the tracing range and slowing down the ignition of the tracer (for tracer cartridges).

All Russian 5.45 mm machine gun cartridges are produced with a steel case coated with green varnish.

5.45x39 cartridge with a regular bullet - 5.45 PS (7N6)

The 5.45-mm cartridge with an ordinary bullet (5.45 PS) is designed to destroy live targets located openly or behind barriers pierced by a bullet, fire weapons and unarmored vehicles. Bullet weight -3.4 g. 5.45 PS cartridges do not have a distinctive color.
In terms of penetration power, the 5.45 PS cartridge is almost equivalent to the 7.62 mm cartridge mod. 1943 with a PS bullet, significantly superior to it in terms of direct shot range.

The first modernization of the cartridge was undertaken in 1987 and led to the replacement of the bullet core material, which began to be made from durable steel grades followed by heat treatment. The geometric dimensions and design of the bullet remained unchanged. Distinctive coloring they don't have bullets.

Main characteristics of the 5.45 PS cartridge

Cartridge weight, g: 10.5
Bullet weight, g: 3.4
Initial bullet speed, m/s: 890

5.45x39 cartridge with increased penetration bullet - 5.45 PP (7N10)

The second modernization of the cartridge in the early 1990s was caused by further improvements in body armor. The use of titanium alloy armor plates in them led to a sharp reduction in the penetration of all types of bullets of the 5.45 PS cartridge, including those with a heat-strengthened core.

In 1992, specialists from the Barnaul Cartridge Plant completed the modernization of a 5.45 mm cartridge with a bullet of increased penetration (5.45 PP). The new bullet differs from the bullet of the 5.45 PS cartridge in the core design. The bullet weight increased slightly and amounted to 3.6 g. 5.45 PP cartridges do not have a distinctive color.

The bullet of the new cartridge provided a significant increase in the penetration of personal armor protection. In terms of ballistic characteristics, the bullets of the 5.45 PP and PS cartridges are almost identical and can be used from all types of weapons chambered for the 5.45 mm cartridge.

Main characteristics of the 5.45 PP cartridge

Cartridge weight, g: 10.7
Bullet weight, g: 3.6
Initial bullet speed, m/s: 880

5.45x39 cartridge with armor-piercing bullets - 5.45 BP (7N22) and 5.45 BS (7N24)

Further development of personal armor protection required increasing the penetration of bullets from machine gun cartridges. By the end of the 1990s, at the Barnaul Machine Tool Plant, a 5.45 mm cartridge with an armor-piercing bullet (5.45 BP) was created and put into service in 2002.

The more advanced shape of the core, its greater mass, hardness and strength, ensured an increase in the penetrating action of bullets against solid obstacles. The mass of the bullet was 3.7 g. The head of the bullet was black.

Firing cartridges with armor-piercing bullets does not lead to increased wear of the bore.

Another cartridge with an armor-piercing bullet, also adopted in 2002, was the 5.45 mm cartridge with a bullet with an armor-piercing core (5.45 BS). This cartridge was developed at FSUE TsNIITOCHMASH. Its production has been mastered by the Federal State Enterprise “Amur Cartridge Plant “Vympel”.

The high density of the core material increased the mass of the bullet to 4.2 g. The increase in mass of the bullet, in turn, led to a slight decrease in its initial speed to 840 m/s. Bullets of the 5.45 BS cartridge do not have a distinctive color.

By 2007, through the joint efforts of the FSUE TsNII TOCHMASH and the FKP APZ Vympel, the cartridge with the BS bullet was modernized. The core has undergone modernization again. As a result of the work carried out, the penetration of personal armor protection equipment has significantly increased.

In cartridges with armor-piercing bullets, the requirement for matching trajectories with other 5.45 mm machine gun cartridges is ensured.

Main characteristics of the 5.45 BP / 5.45 BS cartridge

Cartridge weight, g: 10.8 / 11.2
Bullet weight, g: 3.7 / 4.1
Initial bullet speed, m/s: 880 / 840

5.45x39 cartridges with tracer bullets - 5.45 T (7TZ) and 5.45 TM (7TZM)

Cartridge with tracer bullet 5.45 TM (7T3M)

Simultaneously with the 5.45 PS cartridge, the FSUE "TsNII TOCHMASH" developed and adopted a cartridge with a tracer bullet (5.45 T). The tracer of this bullet at a distance of up to 800m leaves a bright luminous red trace, clearly visible day and night. When hitting flammable objects, the bullet can ignite them.

In the late 1990s. When the modernization of tracer cartridges was carried out, the 5.45 T cartridge was also improved. The tracer was refined at the Federal State Unitary Enterprise TsNIITOCHMASH. The new cartridge was named -5.45 mm cartridge with a modernized tracer bullet (5.45 TM). It was put into service in 2002.

The modernization made it possible to increase the tracing range to 850 m and ensured a delay in the ignition of the tracer composition by 50-120 m from the muzzle. This delay in tracer burning allows for better masking firing position arrow.
The bullet heads of all tracer cartridges are painted green.

Further modernization of the cartridges was carried out in order to increase their penetration. FSUE "TSNIITOCHMASH" developed cartridges with BT-03 and BT-05 bullets. At the same time, at the KBAL named after. Koshkin created the 7BT4 cartridge.

Main characteristics of the 5.45 T / 5.45 TM cartridge

Cartridge weight, g: 10.3 / 10.3
Bullet weight, g: 3.2 / 3.2
Initial bullet speed, m/s: 890 / 890
Tracing range, m: 800 / 850

5.45x39 cartridge with armor-piercing tracer bullet - 5.45 BT (7BT4)

For partial replacement of tracer cartridges, the lead cores of which do not provide penetration of body armor, in Design Bureau automatic lines, by the end of the first decade of the 2000s, a 5.45 mm cartridge with an armor-piercing tracer bullet (5.45 BT) was developed. The new cartridge uses a heat-strengthened steel core instead of a lead one. This ensured increased penetration of personal protective equipment. The head of the bullet is green.

Main characteristics of the 5.45 BT cartridge

Cartridge weight, g: 10.2
Bullet weight, g: 3.1
Initial bullet speed, m/s: 900

5.45x39 cartridge with a bullet with reduced velocity - 5.45 US (7U1)

To covertly destroy living targets unprotected by means of personal armor, the FSUE "TsNIITOCHMASH" by the end of the 1970s created the "Canary" rifle-grenade launcher complex consisting of a 5.45-mm AKSB74U assault rifle with a device for silent and flameless shooting PBS-4, as well as cartridge with subsonic initial speed. It received the name - 5.45 mm cartridge with reduced bullet speed (5.45 DC).

The bullet of the 5.45 US cartridge differs in appearance from all other combat 5.45 mm machine gun cartridges. The leading part of the bullet has a stepwise transition to the ogive, its initial speed is about 300 m/s. To ensure the necessary destructive effect, the bullet has a mass of 5.1 g.

The head of the bullet is black with a green belt.

Main characteristics of the 5.45 US cartridge

Cartridge weight, g: 10.9
Bullet weight, g: 5.1
Initial bullet speed, m/s: 300

5.45x39 cartridge with a bullet of reduced ricocheting ability - 5.45 PRS

The 5.45 mm automatic and machine gun complex was created primarily for combined arms combat. Such combat is conducted at relatively long ranges. However, when fighting in populated areas, shooting at short distances with high-velocity bullets with a steel core leads to a significant increase in the possibility of dangerous ricochets from concrete and brick walls of buildings and asphalt.

That is why in the early 2000s, by order of the Russian Ministry of Internal Affairs, specialists from the State Research and Production Association “Special Equipment and Communications” and the Barnaul Cartridge Plant CJSC created a 5.45 mm cartridge with a bullet of reduced ricocheting ability (5.45 PRS). This cartridge can be considered a modernized version of 5.45 PS cartridges. The bullet core is made entirely of lead. This design ensured increased accuracy of fire and uniform deformation of the bullet when it encountered a solid obstacle, which reduced the likelihood of ricochet.
The bullet does not have a distinctive color, but on the bottom of the cartridge case, along with the factory number and year of manufacture, there is a “PRS” stamp.

Main characteristics of the 5.45 PRS cartridge

Cartridge weight, g: 10.9
Bullet weight, g: 3.85
Initial bullet speed, m/s: 860

5.45x39 blank cartridge - 5.45 blank 7X3 (7ХЗМ)

To simulate firing from AK74 assault rifles, RPK74 light machine guns and their modifications during training, as well as for the production of fireworks, a blank cartridge was developed in FSUE TsNIITOCHMASH in 1974-75. Together with the blank firing bushings, screwed onto the muzzle of the barrel of an assault rifle or light machine gun, the blank cartridge ensures the operation of the moving parts of the weapon's automation.
Instead of a bullet in a blank cartridge, a simulator from polymer material white. Inside, the bullet simulator has a cavity, due to which it is destroyed under the influence of powder gases when leaving the barrel bore. The shot is accompanied by a characteristic sound and flame. Cartridge weight 7 g.

By the mid-2000s, a new blank cartridge was developed according to the classical design with an elongated cartridge case neck, crimped with a sprocket and coated with a layer of sealing varnish. The shot is also accompanied by a sound and a flash of flame.

5.45x39 training cartridge - 5.45 UC (7X4)

Training cartridges are used to teach how to load 5.45 mm assault rifles and light machine guns and load magazines. The training cartridge does not contain a powder charge and has a cooled igniter primer. To identify the cartridge, four longitudinal grooves are made on its sleeve.