Researchers of wound ballistics eventually came to the rescue with a perfect technique - high-speed shooting, which allows you to create video at a frequency of 50 frames per second. In 1899, Western researcher O. Tilman used such a camera to capture the process of a bullet wound in the brain and skull. It turned out that the brain first increases in volume, then collapses, and the skull begins to crack after the bullet leaves the head. The tubular bones also continue to collapse for some time after the bullet leaves the wound. In many ways, these new research materials were ahead of their time, although they could shed a lot of light on the mechanism of wound action. Scientists in those days were carried away by a slightly different topic.
Spark photographs of the movement of a bullet in the air. 1 - the formation of a ballistic wave when the bullet moves at a speed significantly exceeding the speed of sound, 2 - the absence of a ballistic wave when the bullet moves at a speed equal to the speed of sound. Source: "Wound Ballistics" (Ozeretskovsky L. B., Gumanenko E. K., Boyarintsev V. V.)
The discovery of the head ballistic wave, formed during the supersonic flight of a bullet (more than 330 m / s), became another reason to explain the explosive nature of gunshot wounds. Western researchers at the beginning of the 20th century believed that a cushion of compressed air in front of the bullet explains the significant expansion of the wound channel relative to the caliber of the ammunition. This hypothesis was refuted from two directions at once. First, in 1943, BN Okunev recorded with the help of a spark photograph the moment a bullet flew over a burning candle, which did not even move.
Spark photograph of a passing bullet with a pronounced head wave that does not even cause the candle flame to vibrate. Source: "Wound Ballistics" (Ozeretskovsky L. B., Gumanenko E. K., Boyarintsev V. V.)
Secondly, a complex experiment was carried out abroad, firing the same bullets from the same weapon at two clay blocks, one of which was in a vacuum - the head wave, naturally, could not form under such conditions. It turned out that there were no visible differences in the destruction of blocks, which means that the dog was not buried at all in the area of the head wave. And the domestic scientist V. N. Petrov has already completely hammered a nail into the coffin lid of this hypothesis, who pointed out that the head wave can be formed only when the bullet moves faster than the speed of sound propagation in the medium. If for air it is about 330 m / s, then sound propagates in human tissues at a speed of more than 1500 m / s, which excludes the formation of a head wave in front of the bullet. In the 1950s, the Military Medical Academy not only theoretically substantiated this position, but, using the example of shelling the small intestine, practically proved the impossibility of propagation of a head wave inside tissues.
Spark photographs of the wound of the small intestine 7, 62-mm bullet cartridge 7, 62x54. 1, 2 - bullet speed 508 m / s, 3, 4 - bullet speed 320 m / s. Source: "Wound Ballistics" (Ozeretskovsky L. B., Gumanenko E. K., Boyarintsev V. V.)
At this point, the stage of explaining the wound ballistics of the ammunition by the physical laws of external ballistics turned out to be passed - everyone understood that living tissues are much denser and less compressible than the air environment, therefore the physical laws there are somewhat different.
It is impossible not to talk about the leap in wound ballistics that happened just before the outbreak of the First World War. Then the mass of surgeons in all European countries was preoccupied with assessing the damaging effect of bullets. Based on the experience of the Balkan campaign of 1912-1913, doctors drew attention to the German pointed bullet Spitzgeschosse or "S-bullet".
Spitzgeschosse or "S-bullet". Source: forum.guns.ru
In this rifle ammunition, the center of mass was shifted to the tail, which caused the bullet to overturn in the tissues, and this, in turn, dramatically increased the volume of destruction. To accurately record this effect, one of the researchers fired 26 thousand shots at the corpses of people and animals in 1913-14. It is not known whether the center of gravity of the "S-bullet" was deliberately shifted by German gunsmiths, or it was by accident, but a new term has appeared in medical science - the lateral action of a bullet. Until that time, they knew only about the direct. The lateral action is to damage tissues outside the own wound channel, which can cause severe injuries even with sliding wounds from bullets. An ordinary bullet, moving in the tissues in a straight line, spends its kinetic energy in the following proportions: 92% in the direction of its movement and 8% in the lateral direction. An increase in the share of energy consumption in the lateral direction is observed in blunt-headed bullets, as well as in ammunition capable of tumbling and deforming. As a result, after the First World War, the basic concepts of the dependence of the severity of a gunshot wound on the amount of kinetic energy transferred to tissues, the speed and vector of this energy transfer were formed in the scientific and medical environment.
The origin of the term "wound ballistics" is attributed to the American researchers Callender and French, who in the 1930s and 1940s worked closely on the gaps of gunshot wounds. Their experimental data again confirmed the thesis about the decisive importance of bullet velocity in determining the severity of the "firearm". It was also found that the energy loss of the bullet depends on the density of the damaged tissue. Most of all, the bullet is "inhibited", naturally, in the bone tissue, less in the muscle and even less in the lung. Particularly severe injuries, according to Callender and French, should be expected from high-speed bullets flying at speeds of over 700 m / s. It is precisely such ammunition that is capable of causing true "explosive wounds".
Diagram of bullet movement along Callender.
The scheme of the bullet movement according to LB Ozeretskovsky.
One of the first who recorded the predominantly stable behavior of a 7, 62 mm bullet were domestic scientists and doctors L. N. Aleksandrov and L. B. Ozeretsky from the V. I. S. M. Kirov. By shelling clay blocks 70 cm thick, scientists found out that for the first 10-15 cm such a bullet moves steadily and only then begins to unfold. That is, for the most part, 7.62-mm bullets in the human body move quite steadily and, at certain angles of attack, are able to pass right through. This, of course, sharply reduced the stopping effect of the ammunition on the enemy's manpower. It was in the post-war times that the idea of the redundancy of the 7, 62-mm automatic cartridge appeared and the idea of changing the kinematics of the bullet's behavior in human flesh was ripe.
Lev Borisovich Ozeretskovsky - professor, doctor of medical sciences, founder of the national school of wound ballistics. In 1958 he graduated from the IV faculty of the Military Medical Academy named after V. I. SM Kirov and was sent to serve as a doctor of the 43rd separate infantry regiment of the Leningrad Military District. He began his scientific activity in 1960, when he was transferred to the position of a junior researcher in the physiological laboratory of the 19th scientific research artillery test range. In 1976 he was awarded the Order of the Red Star for testing a complex of small arms of 5, 45-mm caliber. A separate area of activity of the colonel of the medical service Ozeretskovsky L. B.in 1982, the study of a new type of combat pathology began - blunt trauma to the chest and abdomen, protected by a bulletproof vest. In 1983 he worked in the 40th Army in the Republic of Afghanistan. For many years he has been working at the Military Medical Academy in St. Petersburg.
To help in the difficult task of increasing the lethal effect of a bullet came sophisticated recording equipment - pulse (microsecond) radiography, high-speed filming (from 1000 to 40,000 frames per second) and perfect spark photography. Ballistic gelatin, which simulates the density and consistency of human muscle tissue, has become a classic object of "shelling" for scientific purposes. Usually blocks weighing 10 kg are used, consisting of 10% gelatin. With the help of these novelties, a small discovery was made - the presence of a temporary pulsating cavity in the tissues affected by the bullet. The head part of the bullet, penetrating into the flesh, significantly pushes the boundaries of the wound channel both along the axis of movement and to the sides. The size of the cavity significantly exceeds the caliber of the ammunition, and the lifetime and pulsation are measured in fractions of a second. After that, the temporary cavity "collapses", and the traditional wound channel remains in the body. The tissues surrounding the wound canal receive their dose of damage just during the shock pulsation of the temporary cavity, which partly explains the explosive nature of the "firearm". It should be noted that now the theory of a temporary pulsating cavity is not accepted by some researchers as a priority - they are looking for their own explanation of the mechanics of a bullet wound. The following characteristics of the temporal cavity remain poorly understood: the nature of the pulsation, the relationship between the dimensions of the cavity and the kinetic energy of the bullet, as well as the physical properties of the target medium. In fact, modern wound ballistics cannot fully explain the relationship between the caliber of a bullet, its energy and those physical, morphological and functional changes that occur in the affected tissues.
In 1971, Professor A. N. Berkutov, in one of his lectures, expressed himself very accurately regarding wound ballistics: "The unrelenting interest in the theory of a gunshot wound is associated with the peculiarities of the development of human society, which, unfortunately, often uses firearms …" Neither subtract nor add. Often this interest is faced with scandals, one of which was the adoption of small-caliber high-speed bullets 5, 56 mm and 5, 45 mm. But this is the next story.
