One of the most persistent stereotypes in the field of small arms is the thesis that the minimum caliber that provides a sufficient stopping effect of a pistol cartridge is 9 mm. Let's try to figure out how true this is.
To begin with, let us remember where, in addition to the task of defeating a person, the stopping action is most in demand. This is a hunt for representatives of the animal world.
Stopping effect of hunting ammunition
The need for a high stopping effect of a hunting weapon is due to two reasons. First, it increases the safety of the hunter. Most animals are "tight on the wound." In other words, a wounded animal, be it a wild boar, a wolf or a bear, when shooting close, may well attack the hunter and inflict injuries and wounds on him, even fatal. The second task, solved by the high stopping effect of cartridges, is the absence of wounded animals on the hunt. Making and not getting a "wounded animal" is a serious "joint" in the hunting environment, in addition, it may even be financially punishable in some hunting grounds.
The minimum acceptable ammunition for hunting animals from the big African five is.375 H&H Magnum (9, 53x91 mm) or its German counterpart 9, 3x64 mm. More powerful cartridges are calibers.416 (10, 57x74 mm),.470 (12, 1x83 mm),.505 Gibbs (12, 8x80 mm).
As we can see, these ammunition is quite "human" caliber 9-12 mm, no one makes them with a caliber of 20-25 mm or more, which, it would seem, can be expected based on the ratio of the size and weight of humans and animals from the big African five, especially taking into account the almost pistol distance of the shot when hunting these animals. The main emphasis is on increasing the initial energy of the shot, which for "African" calibers can be 6000-12000 J.
The question arises: if the matter is not in the caliber, then why not reduce it by increasing the bullet speed? The problem is that increasing the speed of the bullet above a certain limit has an extremely negative effect on the resource of the barrel. The range of initial velocities of most modern army cartridges lies in the range of 800-1000 m / s, hunting ones are often even lower. Accordingly, in order to provide sufficient muzzle energy to defeat the beast, it is necessary to increase the mass of the bullet. And the caliber here is primarily a consequence of the need to increase the mass of the bullet, and not the fact that a 12 mm bullet will hit an elephant better than a 10 mm bullet, with the same energy.
If we talk about shooting at long and medium ranges, before here the determining factors in choosing the caliber and mass of bullets is the need to ensure optimal aerodynamic characteristics, due to the shape of the bullet, and to save the energy of the bullet at a considerable distance, given the fact that lighter bullets lose speed faster and are susceptible to wind drift.
As an extreme example of small-caliber high-velocity ammunition, we can mention the Gerlich bullet for tapered barrels. Gerlich's bullet diameter was 6, 35 mm, bullet weight 6, 35 g, muzzle velocity reached 1740-1760 m / s, muzzle energy - 9840 J. This record for small-caliber bullets and small mass has not been broken so far. Gerlich's bullet at a distance of 50 m broke through a hole with a diameter of 15 mm in a steel armor plate 12 mm thick, and in a thicker armor made a funnel 15 mm deep and 25 mm in diameter. An ordinary 7.92 mm Mauser rifle bullet left only a small depression of 2-3 mm on such armor. The developments on the Gerlich bullet were used in the development of high-speed projectiles, but such ammunition did not become widespread in small arms due to the low resource of the weapon under them, amounting to about 400-500 rounds.
Backfill question: what will happen to the representative of the big African five when a conditional Gerlich bullet hits him, capable of making a 15-mm hole in an armor plate 12 mm thick, or its modern analogue with an initial energy of about 10,000 J?
Stopping action in case of human injury
Let's return to the stopping action when a person is defeated. It is believed that the stopping effect grows with the caliber of the bullet, that is, the.45 ACP (11, 43x23 mm) ammunition has a greater stopping effect than the 9x19 mm ammunition, while the 9 mm caliber is considered the minimum sufficient for pistols in terms of stopping action …
The question is that the weight and size characteristics of people are quite different. On average, a person's height varies from 165 cm to 190 cm, respectively, the sizes of the chest and internal organs differ. This is not counting the various features of the structure of the body, the shape and location of internal organs, the presence / absence of fatty deposits, differences in bone density, reaching 25 - 30%, or the volume of muscle tissue.
The diameter of the 11.43 mm bullet is 1.27 times larger, the area is 1.61 times larger than that of the 9mm bullet. The question arises, is the stopping effect of a 9 mm bullet sufficient for all "standard sizes" and "form factors" of a person, or does it work only on the lower / upper level?
If a cartridge of 9 mm is enough to defeat the "largest" representative of the human race, then a person of smaller dimensions can be just as effectively hit with a bullet of 7, 62 mm? Where is the limit of the minimum allowable caliber, and why is it considered that this is the notorious 9 mm?
Why was 7, 62x25 TT replaced with 9x18 mm PM?
It would seem that this is it - a real confirmation of the effectiveness of cartridges of 9 mm caliber. After all, the 7.62x25 TT cartridge is 1.5-2 times more powerful than the 9x18 mm PM cartridge. And it was not the army of Burkina Faso who did this, but one of the strongest and most equipped armies in the world - the armed forces of the USSR.
The question immediately arises. Why invent a new 9x18 mm cartridge when there were already widespread 9x19 mm and 9x17 mm (.380 ACP) cartridges? What reasons prompted the armed forces and the USSR Ministry of Internal Affairs to adopt a pistol with a less powerful cartridge than 9x19 mm, but more powerful than 9x17 mm?
With regard to the 9x19 mm cartridge, such a factor as "necessary and sufficient" most likely worked. At the time of the adoption of the Makarov pistol and the 9x18 PM cartridge into service, their characteristics made it possible to confidently hit all the necessary targets. If we talk about the defeat of a person unprotected by personal body armor (NIB), then the characteristics of the 9x18 PM cartridge are still quite relevant, especially when combined with a store of increased capacity. At the same time, the use of a 9x19 mm cartridge complicated the design of the weapon due to the need to reduce the recoil speed of the bolt, while for cartridges of lower power it was possible to use a free shutter scheme, which favorably affected the weight, dimensions and cost of the weapon.
As for the 9x17 cartridge, either the unwillingness to accept the ammunition of a potential enemy, or the desire to develop a new cartridge with the concomitant receipt of the due prizes and awards for this, most likely played a role here, in the end, no one has canceled personal interest. In the 30s of the last century, on the basis of the 9x17 mm cartridge in Germany, by extending the sleeve from 17 to 18.5 mm, the 9x18 Ultra cartridge was created. Presumably, it was the 9x18 Ultra cartridge that was chosen as a prototype when creating the 9x18 mm cartridge.
In principle, the 9x18 mm cartridge does not have any special advantages over the 9x17 mm cartridge. It is certainly possible to say that a 9x18 mm cartridge is more powerful than 9x17 mm, but it is not difficult to increase the power of the latter to the level of a 9x18 mm cartridge, which confirms the appearance of such 9x17 mm cartridges as the Buffalo Bore Ammunition 380 ACP (Auto) + P with initial energy over 400 J.
Why was the powerful cartridge 7, 62x25 mm replaced with a much less powerful 9x18 mm? The reasons are the same as in the case of the 9x19 mm cartridge. With all its advantages, the TT pistol is extremely inconvenient in operation, has a small ammunition for its size and weight, is unsafe in operation due to the lack of a fuse and a safe trigger from the combat platoon. A new, less powerful cartridge of 9x18 mm was chosen based on the need to create a compact weapon that is as convenient as possible in everyday use.
But still why 9 mm and not 7.62 mm? Initially, two samples were required to submit to the competition, in calibers 7, 65 mm and 9 mm, which indicates that there is no prejudice regarding the caliber 7, 62/7, 65 mm. Ultimately, a new 9x18 mm cartridge was chosen, the alleged reasons for the appearance of which are described above. Various sources say that the reason for choosing a 9 mm cartridge is a higher stopping effect of the latter, compared to cartridges of 7, 62/7, 65 mm action”, and its application to the choice of a pistol cartridge, could not be found. In all available sources it is indicated that the 9 mm caliber cartridge was chosen, among other things, because of its greater stopping effect, period.
In fact, there may be several reasons, for example, the high manufacturability of the 9 mm cartridge due to the absence of unnecessary operations in the manufacture of the bottle-shaped sleeve (it will turn out to be cylindrical or too long, which will interfere with its feeding in a compact pistol, or will have a limited volume and will not allow bullet necessary initial energy). And the psychological factor cannot be written off - the larger the caliber, the larger the diameter of the barrel, the larger the bullet, it means "more powerful." After all, many people in the US still love the.45 ACP cartridge, despite the fact that the US military switched to the 9x19 mm cartridge forty years ago.
Based on the foregoing, there is no sufficient reason to believe that the reason for choosing a pistol cartridge of 9 mm caliber was its greater stopping effect compared to a cartridge of 7.62 mm. If at the time of the creation of the Makarov pistol and the 9x18 mm cartridge, the NIB would already be widespread or there would be a possibility of meeting a fattened steroid and "drugged" opponent with psychotropic drugs with a fighting dog in the kit, then the active use of the 7, 62x25 mm cartridge could well continue to the present day. The Makarov pistol and the 9x18 mm cartridge might simply not have been born, and the development of domestic short-barreled weapons would have followed the western path, with the creation of multi-charge pistols with a short barrel stroke.
So why is it still believed that 9 mm is the minimum caliber to ensure the stopping effect of short-barreled weapons? It was not possible to find clear answers to this question. Numerous studies, which we talked about in one of the previous articles, do not give an exhaustive answer, there is not even a sane quantitative definition of "stopping action".
In the next article, we will consider the essence of the stopping action, clarify its definition, try to characterize it quantitatively, and also try to determine which damaging factors of ammunition of modern weapons have the maximum effect on it.
