People familiar with weapons know legends about bullets with a displaced center of gravity. The essence of the majority boils down to one thing: the chaotic trajectory of movement allows the bullet to go through two holes spaced throughout the body. Such legends are told in all seriousness and with burning eyes. Is this true, are there bullets with a displaced center of gravity, and what is the principle of their action?
Cartridges with a displaced center of gravity - what is it?
The answer to the question of whether there are bullets with a displaced center of gravity has long been beyond doubt. In the years 1903-1905, blunt-pointed bullets for rifles were replaced by pointed analogs of two types: light, which allow firing at close range, and heavy, designed to fire at long distances. In comparison with blunt-ended, such bullets had the best aerodynamic characteristics. The leading countries of the world adopted them almost at the same time with some differences: heavy ammunition first appeared in France, England and Japan, and light ammunition in Russia, Germany, Turkey and the United States.
Appearance story
Lightweight bullets had several advantages with the exception of improved aerodynamics. The reduced weight of the bullet allowed to save metal, which was profitable given the huge volumes of ammunition produced. The decrease in mass led to an increase in the initial velocity and an improvement in ballistics, which affected the range of the shot.
Based on the experience of military operations at the turn of the 19th and 20th centuries, the maximum range of firing by soldiers with an average level of training was determined. An increase in the effectiveness of aimed fire at a distance of 300-400 meters became possible after the introduction of light bullets without changing the training of shooters. Heavy bullets were used for firing at long distances from machine guns and rifles.
Rifles designed for blunt-pointed bullets during the fighting showed a lack of light pointed bullets. The gentle rifling of the gun trunks was not enough to stabilize the light bullets, which led to their instability in flight, a decrease in breakdown stability and accuracy, and an increase in drift under the influence of a side wind. The stabilization of a bullet in flight became possible only after the artificial transfer of its center of gravity closer to the rear. For this purpose, the nose of the cartridge was deliberately facilitated by placing light material in it: fiber, aluminum or cotton.
The most rational way out of this situation was found by the Japanese, who created a shell of bullets with a thickened front part. This made it possible to find a solution to two problems at once: to shift the center of gravity back due to the smaller specific gravity of the shell material than that of lead, and to increase the bullet's breakdown ability due to thickening of the shell. The innovation introduced by the Japanese laid the foundation for bullets with a displaced center of gravity.
The reason for the transfer of the center of gravity of the bullet was rational and aimed at improving stabilization, but not at all at achieving a chaotic trajectory of motion and causing maximum damage when it enters the body. When hit in body tissue, such ammunition leaves neat holes. If the question of whether there are bullets with a displaced center of gravity can be considered closed, then questions about the nature of the wounds they inflicted remain open, giving rise to myths and legends.
Nature of damage
What is the reason for the myths about bullets with a displaced center of gravity and a chaotic trajectory of their movement? Are they true, or are they just tales and legends?
For the first time, serious in comparison with a small caliber bullet wounds were witnessed after hitting a.280 Ross cartridge of 7 mm caliber. The cause of extensive damage was the high initial velocity of the bullet with a displaced center of gravity - about 980 m / s. Tissues hit by a bullet at this speed are subjected to water hammer. This led to the destruction of bones and nearby internal organs.
The M-193 bullets supplied for the M-16 rifles inflicted more severe damage. An initial speed of 1000 m / s endowed them with hydrodynamic shock properties, but the seriousness of the injuries was due not only to this. When bullets hit the soft tissues of the body, they pass 10-12 cm, turn around, flatten and break in the region of the annular groove necessary for the bullet to fit into the sleeve. The bullet moves forward with the bottom, and the fragments formed during the fracture hit the surrounding tissue at a depth of 7 cm from the bullet hole. The combined effects of water hammer and splinters are exerted on internal tissues and organs. As a result, small-caliber bullets leave inlets with a diameter of 5-7 centimeters.
Initially, the cause of this action of a bullet with a displaced center of gravity of the M-193 was considered to be an unstable flight associated with overly shallow rifling of the barrel of the M-16 rifle. The situation could not be changed after the creation of a 5.56x45 cartridge for the M855 heavy bullet, designed for steeper rifling. The stabilization of the bullet was successful due to the increased speed of rotation, however, the nature of the wounds remained unchanged.
It is logical that the action of a bullet with a displaced center and the nature of the wounds inflicted by it do not depend on a change in the center of gravity. Damage depends on the speed of the bullet and other factors.
Classification of bullets in the USSR
The ammunition classification system adopted in the USSR changed over different periods of time. There were several modifications of the 7.62 caliber rifle bullet released in 1908: heavy, light, incendiary, armor-piercing, tracing, armor-piercing incendiary, differing in color designation of the bow. The versatility of the cartridges made it possible to release several of its modifications, which were used in carbines, rifles and machine guns. A weighted version, striking targets at distances of more than 1000 meters, was recommended for sniper rifles.
The 1943 model (a bullet of 7.62 mm caliber for an intermediate cartridge type) acquired one new modification, having lost two old ones. A bullet with a displaced center of gravity was produced in several versions: tracer, standard, incendiary, armor-piercing incendiary, low speed. Weapons equipped with PBBS - a device for silent and flameless firing, were charged only with the latest modification.
The expansion of the range of ammunition occurred after the introduction of a caliber of 5.45 mm. The modified classification of bullets with a shifted center of gravity included supplies of 7H10 with increased penetration ability, with a steel core, low-speed, tracer, for idle cartridges and armor-piercing 7H22. Bullets for blank cartridges were made of a brittle polymer that completely collapses in the bore when fired.
NATO marking and classification
The classification of small arms bullets adopted in the countries of the USA and Europe differs from that in the USSR. The color coding of NATO bullets with a displaced center of gravity also varies.
Lrn
An all-lead full-shell bullet is the cheapest and earliest modification. Practically not used today, the main scope is sports target shooting. It has an increased stopping effect in the defeat of manpower due to deformation during impact. The probability of a rebound is almost minimal.
Fmj
A common and most famous type of shell bullet. Used in all types of small arms.
The high-strength shell is made of brass, steel or tompac, the core is made of lead. A large impulse is achieved due to the mass of the core, good penetration is provided by the shell.
Jsp
Half-shell bullets from a “glass” filled with lead with a rounded or flat nose formed from it. The stopping effect of a bullet with a displaced center of gravity of this type is higher than that of the shell, since deformation when hit occurs in the bow, which increases the cross-sectional area.
Bullets practically do not ricochet and have a low backstop effect. Prohibited for use in hostilities by international conventions. It can be used for self-defense and by police units.
Jhp
Half-shell bullet equipped with an expansive recess. The structure does not differ from the semi-shell, but has a shaped recess in the nose designed to enhance the stopping effect.
The action of a bullet with a displaced center of gravity of this type when hit is aimed at "opening" with an increase in cross-sectional area. It does not inflict through wounds; when it enters soft tissues, it causes significant damage and severe injuries. The prohibitions are the same as for a half-shell bullet.
AP
Armor-piercing bullet consisting of a core of hard alloys, a lead filler, a brass or steel shell. The latter is destroyed when a bullet hits the target, allowing the core to break through the armor. Lead not only provides momentum, but also lubricates the core, avoiding rebound.
Thv
Achieving high speed and sharp braking of a monolithic high-speed bullet when it hits the target with the subsequent transfer of kinetic energy is possible due to the reverse envelope shape. Sale to civilians is prohibited, it is used only by special units.
Gss
Ballistic controlled bullets. Consist of shot filler, shell and bow. They are used for firing at targets that are not protected by armor, in conditions requiring accurate hits without penetration and ricochet, for example, when shooting in the cabin. The destruction of a bullet occurs when it enters the body with the subsequent formation of a stream of small fractions, causing severe wounds. It is used in the work of counter-terrorism units.
Soviet answer NATO
It turns out that the answer to the question of whether there are bullets with a displaced center of gravity is unambiguous, but the emergence of myths and legends about their properties can not be explained.
In response to the adoption by the NATO countries of a 5.56x45 cartridge, the Soviet Union created its own cartridge of a reduced caliber - 5.45x39. The cavity in the bow deliberately shifted the center of gravity backward. Ammunition received an index of 7H6 and was widely used during battles in Afghanistan. During the "baptism of fire" it turned out that the nature of the wounds and the principle of the bullet with a displaced center of gravity are very different from those of the M855 and M-193.
Unlike small-caliber American bullets, the Soviet one, when hit in soft tissue, did not turn its tail forward, but began to randomly turn over as it advanced in the wound channel. 7H6 destruction did not occur, since the steel strong shell absorbed hydraulic loads during movement in the tissues.
Experts believe that the cause of this trajectory of a bullet with a displaced center of gravity 7H6 was the shifted center of gravity. The stabilizing factor ceased to play its role after a bullet hit the body: it slowed down its rotation. The reason for further tumbling was the processes occurring inside the bullet. The lead shirt located near the bow was shifted forward due to sharp braking, which additionally shifted the center of gravity and, accordingly, the point of application of forces during the movement of the projectile in soft tissues. Do not forget about the bending nose of the bullet itself.
The complex and severe nature of the wounds inflicted depends on the heterogeneity of the structure of the tissues. Serious damage with 7H6 bullets was recorded at the final depth of the wound channel - more than 30 cm.
The mythical rumors about "entered the leg, went through the head" are relatively explained by the curvature of the wound channel, which is noticeable in medical photos. Bullets with a displaced center of gravity leave inlet and outlet openings that do not correspond to each other. Deviations of the trajectory of the 7H6 ammunition are recorded only at a tissue depth of 7 cm. The curvature of the trajectory is noticeable only with a long wound channel, while the damage done remains minimal with edge hits.
A sharp change in the trajectory and principle of action of a bullet with a displaced center of gravity in theory is possible when it hits a bone along a tangent. Of course, when hit in a limb, the ammunition will definitely not go over your head: for such a wound channel, it will not have enough energy. The maximum penetration depth of a bullet when shooting point-blank in ballistic gelatin does not exceed 50 cm.
About ricochets
Among military personnel with extensive experience in practical shooting, there is an opinion that bullets with a displaced center of gravity are prone to ricochets. In conversations, examples are often given of rebounding from window glasses, water and branches when shooting at an acute angle or multiple reflection of a bullet from the surfaces of stone walls in confined spaces. In fact, the situation is somewhat different, and the shifted center of gravity does not play any role in this.
There is a common pattern for all ammunition: the minimum probability of a rebound in blunt heavy bullets. It is logical that 5.45x39 ammunition does not belong to this category. When hit at an acute angle, at the same time, the momentum transmitted to the obstacle may be so small that it is not enough to destroy it. The cases of rebounding of lead shot from water are not myths, despite the fact that shot does not have any shifted center of gravity.
Regarding the reflection from the walls of the enclosed space: indeed, the M193 bullets are less susceptible to it, unlike the same 7H6 ammunition. However, this is achieved only due to the lower mechanical strength of American bullets. When colliding with an obstacle, they undergo significant deformation, which leads to a loss of energy.
