Requirements for the improvement of small weapons stood before the designers always and at all times. Even in spite of the fact that the current level often seemed to have reached the limit of its development. For example, the Russian “Artillery Journal” in the number 4 for 1857 wrote a year that “small arms reached such perfection that, apparently, nothing more could be expected ...” But after a while, due to the appearance of smokeless powder and a metal sleeve with the central battleground cap, the last one occurred in the newest stories a qualitative (revolutionary) leap, thanks to which the cartridges and small arms have reached their present level of development.
But what to do next, what ideas or inventions can provide a fundamental improvement in progress? Obviously, something new is needed. But it is also obvious that, besides the search for new solutions, it is necessary to know and understand the experience of previous generations. In order not to reinvent the wheel and not repeat the mistakes of others. And, perhaps, carefully consider some old ideas if they are worth it.
Among the experimental work of the recent past, one of the most promising and promising was the development of cartridges with feathered sub-caliber bullets for small arms, which were conducted for a long time both here and abroad. One of the authors of Western studies, Irvin R. (Irvin R. Barr), was in love with insanity in the concept of sub-caliber. And in domestic industry documents from the middle of the 70-s, these developments were given the status of “the most important and promising direction”. But cartridges with OPP (feathered sub-caliber bullets) have not been put into service either here or abroad. So what was it, why didn’t it take off? This article is devoted to the subject and history of these developments and is largely based on data from the monograph. "Small arms ammunition" Vladislav Nikolaevich Dvoryaninov.
It is necessary to begin the presentation with an explanation of the basic reasons for such keen interest. The figure shows a shot with a subcaliber bullet (left) and a classic, “caliber” version. The sub-caliber bullet (1) is designed as a feathered arrow. Its diameter is smaller than the caliber of the barrel (3) and therefore it is called subcaliber. The shape of the bullet in the form of an arrow was chosen because it stabilizes on flight with its own feathering, and not by rotation, as we used to. Because in order to give it the required rotation by ballistics, such a slope of rifling is needed, which turns the barrel practically into a nut ... The second most important constructive detail is the light pulling ring (2), which is connected to the bullet. In practice, it has received the well-established name "pallet", which we will use in the future. The pallet senses the pressure of the powder gases (4) with the entire area of its cross section “S1” and can accelerate with the bullet to much higher speeds than the classical caliber bullet (5, right) of the same weight, but smaller area “S2”. After departure from the barrel, the pallet is separated and the bullet continues its flight to the target independently. Thus, the sub-caliber design makes it possible to achieve an improvement in all ballistic parameters of a shot, which, with comparable dimensions of cartridges and caliber, leads to a noticeable increase in the range of a direct shot (DPA) with a reduced recoil impulse, but with the same pressure of powder gases.
Any specialist, having appreciated such possibilities of the subcaliber scheme, really should be delighted. But I have to think right away: how, in one way or another, first ensure reliable connection of the pallet with the bullet when moving in the barrel, and then their easy and reliable separation? And it will be right, because this is the key to the practical implementation of the whole idea.
In the US, Irwin Baer and his associates, whose experienced 1954 patent cartridges are shown in the photo, relied on keeping the bullet in a solid tray due to friction caused by squeezing the powder powder and separating it from the bullet due to the destruction of the muzzle nozzle with knives. At the same time, based on the recommendations of the Department of Operations Research (ORO) to improve the effectiveness of handguns, they have chosen to develop a cartridge version in caliber 5,56 mm with light (0,65 g) but very high-speed (Vо = 1430 m / s) feathered sub-caliber bullet, providing, according to their calculations, sufficient stopping power at the required ORO destruction distances, as well as a low recoil momentum: from 0,30 to 0,18 kgf * c.
Domestic research on feathered sub-caliber projectiles began in the USSR back in 1946 (by artillerymen). In 1960, an armor-piercing OPS was adopted for the 100-mm smooth-bore anti-tank gun "Rapier" T-12. Under the influence of the success of this work in 1960, the group of A.G. Shipunov at NII-61, a theoretical assessment of the possibility of using a similar design for projectiles was carried out aviation automatic cannons. At the same time, a domestic project began to create a new 5,45-mm rifle complex. Therefore, Shipunov proposed to work out the idea of a sub-caliber ammunition in relation to small arms cartridges (and not under the influence of "intelligence data", as some "experts" mistakenly point out). The development of the general idea was attended by V.P. Gryazev, who in the previous 1959 was one of the performers of research work on the study of foreign experience in the development of new small-caliber complexes (as a gunsmith). The draft design of the cartridge was commissioned by D.I. Shiryaev, who “did not spend a full working day on this”.
The final proposal was a cartridge with OPP, recoil pulse 0,5 kgf · s with a caliber of smooth barrel 8,0 mm. The authors considered the proposed method of connecting a pallet and a sabot bullet to be a highlight and a principal novelty. They wrote: "We are aware of the existence of mines with separating pallet ... We claim only a new form of performing a subcaliber shot, and not a subcaliber shot as a whole ... Creating a small caliber subaliber feathered bullet ... became possible only after we had found a way to mount the pallet on the pool due to the friction forces generated during the compression of the pallet sectors with gases ... " What later was issued a copyright certificate. Below is the original drawing for this application and a photo of the first variant of the arrow-shaped bullet made on it.
Attentive reader, by the way, can break the head over the question: how, according to this drawing, was it supposed to ensure fixation of the cartridge case in the weapon chamber? The technological part of the proposal may first seem boring and tedious details. But her, to put it mildly, unconventionality, is interesting and deserves attention. The pallet blank in the form of a duralumin tube with longitudinal cuts (in order to get a multi-sector pallet as a result) was initially supposed to be “pressed tightly onto an arrow-shaped bullet”. Then, assemble, grind the center and tail of the tube. After this, the entire sleeve assembly is patronized, and in this form, together with the sleeve, grind the head of the tube, resulting in the finished sectors of the pallet. After that, to make the equipment of the cartridge powder through the hole in the bottom of the sleeve, where the sleeve with the capsule or the capsule would eventually be pressed in ... Ballistic calculations were made, but an unattainable good ballistic coefficient of the future sabot bullet was made (1,9 м2 / kgf according to Sachchi) ), which led to the fantastically good results of calculations on the flatness of the trajectory and the energy of the bullet at typical firing ranges. Based on the above, Shiryaev prepared relevant posters and a general presentation of the idea. Which is extremely liked the authorities.
As a result, Dmitry Ivanovich Shiryaev in the middle of 1960 of the year was temporarily transferred to the cartridge department No. 23 for the practical implementation of the proposed idea. Where in the cartridge direction he worked until the end of 1961 of the year. Such a short participation of one of the initiators is explained by the fact that during the very first experiments it turned out that none of the initial proposals was suitable. It was not possible to achieve the correct functioning of the shot - the pallets broke off the boom in the barrel even at half the design value of the maximum pressure of the powder gases. Initially, we had to abandon the pressing of the pallet blank on the boom and its step-by-step turning, from small semicircular grooves on the boom and, most importantly, from using friction forces for coupling the boom and the pallet. We tried to use for the coupling of the sectors of the pallets and the bullet metric thread, but it also did not give results. The measured ballistic coefficient of the first arrow-shaped bullets turned out to be 4,5 m2 / kgf instead of 1,9 m2 / kgf.
Despite the apparent failure of the first experiments, the cartridge group continued research. The group consisted in those years of data from the young planters I.P. Kasyanov, O.P. Kravchenko and, later, V.A. Petrova (each of which later became the winner of the USSR State Prize in various works).
All elements of the cartridge have been re-designed. There are two options for thin-walled shells. The shape of the bullet and pallets has changed markedly. For their reliable grip has already been used "comb", like artillery OPS. The caliber of the smooth barrel was changed to 7,62-mm. All elements of arrows and pallets were made in pilot production using the methods of turning, milling and metalworking, cartridges were assembled almost by hand. Aluminum pallets were made in pairs, without the possibility of their mutual replacement. As a result, the developers managed to achieve a certain progress and ensure the normal and stable operation of the shot, approaching the design values. The following photo shows mockups of experienced 7,62 / 3-mm 1963-64 cartridges.
The most important question at this stage of the work was to determine how far the sabot meets the requirements for a promising weapon system. The most disappointing were the test results of the end of 1962 of the year for the destructive action of arrow-shaped bullets, which turned out to be unacceptably low and significantly inferior to both regular patrons and prospective demands of the military.
A bit earlier, in May and June of the 1962 of the year, the conclusion “The principle acceptability of the cartridge with a feathered sub-caliber bullet from the point of view of the safety of firing bullets from a flying pallet and the absence of special bullets in the ammunition". This conclusion is of paramount importance, since for the entire subsequent history of the development of cartridges with OPP it remained the only one in which the question of the expansion of sectors was investigated in a comprehensive manner. Conducted by a highly qualified specialist, an officer of the Rzhev landfill, Ph.D. M.S. Shereshevsky, this study included not only the determination of the danger of the sectors of the pallets at different distances from the shooter, but also contained a detailed analysis of the possibility of finding their fighters in the area of expansion. It was shown that their presence in the danger zone, at small lateral distances from the trajectory of fire, is prohibited and unlikely, since such a position of a fighter is very dangerous for him regardless of what kind of ammunition is fired at. If such a finding can take place, then in very rare cases and at a distance of 25-30 meters from the shooter, where the sector is no longer dangerous. On the basis of what was made fundamentally important conclusion that "shooting with feathered bullets is safe for his troops».
In 1963, the debugging of the prototype model of the automatic machine AO-27 for cartridges with OPP, which was developed by D.I. Shiryaev, V.S. Yakushchev and Yu.G. Marychev. In terms of the energy of moving parts, the AO-27 machine gun practically did not differ from the AKM machine gun. But "In the process of testing the prototype of the machine, it was revealed that the metal of the pallet (aluminum alloy D16T) sticks intensively to the surface of the bore when maintaining automatic fire ... When you shoot more 150 bullets firing out of the bore with large nutation angles and sharp drops from the average trajectories". Quickly, using the anodizing method of pallets, this effect was not completely eliminated. Therefore, after every 60-65 shots, it was necessary to clean the bore of an 20-% gun with an alkali solution heated to 90 hail. C, and its rather long exposure in the barrel bore, plugged with a rubber stopper. Despite this, the dispersion of shots during automatic shooting was, to put it mildly, very large.
According to the results of all the tests carried out, the Rzhev testing ground was given a very positive assessment of the potential of cartridges with OPP. Particularly noted was the achievement of the WI with the 0,5 kgf · s recoil impulse, which was unattainable for the cartridges of the classical caliber bullet scheme. However, with the recommendation to continue the work, very stringent requirements for revision were formulated:
1. To significantly increase the striking and stopping effects of arrow-shaped bullets.
2. Ensure accuracy of shooting single shots at the level of regular ammunition.
3. Develop special, first tracer bullets.
The above requirements fully reflected the “natural flaws” of the sub-caliber scheme for small arms cartridges.
Works on cartridges with OPP were carried out within the framework of research to create a new automatic low-impulse cartridge, and not for the sake of the beauty of the idea itself. In the mainstream towards the end of 1964, very significant progress has already been made. Tests confirmed that the experienced 5,45-mm cartridges for accuracy, slaughter, stopping and penetration actions almost meet the requirements. Therefore, the "caliber" option won the arrow-shaped, as they say, for a clear advantage. Including due to its “classical” manufacturability. Therefore, since the end of 1964, research on “automatic” 7,62 / 3-mm cartridges with OPP has been virtually abandoned.
But the patrons were haunted by the potential benefits of the sabot scheme. Moreover, they have been achieved in practice and many nuances of the design have already been investigated. It was also clear that the identified deficiencies are very complex and possibly insurmountable problems. But they can be solved only by continuing intensive research.
In the middle of 1964, based on his own experience of work on the topic, I.P. Kasyanov and V.A. Petrov completed outline design and calculation of the ballistic characteristics of not automatic, but machine-rifle cartridge with a feathered sabot bullet: caliber of a smooth barrel 10 mm, bullet diameter 4,5 mm, bullet weight 4,5 gram, s / s. The calculations showed that the proposed cartridge should exceed the standard domestic and foreign rifle cartridges. It was also expected that the slaughter effect of 1300-mm arrow-shaped bullet would be at the proper level, as more heavy and overall.
Customers approved this direction of work and agreed on the TZ, the main conditions of which were the direct shot range of at least 600 m, the slaughter effect and accuracy of shooting single shots - no worse than a regular rifle cartridge with an LPS bullet. So domestic work on ammunition with sub-caliber feathered bullets passed from the "weight category" of machine guns to machine-gun and rifle.
Vladislav Dvoryaninov, a young specialist, a graduate of the LVNM 1965 of the year, who by that time had already become a leading design engineer and had a certain experience in the work on the machine gun rifle theme, was appointed as the responsible executor for this patron from 1960.
When designing the first version of the 10 / 4,5-mm cartridge, previous experience was fully used. Two-sector pallets were still made of aluminum alloy. The sleeve was made from a semi-finished standard rifle sleeve. The steel feathered sub-caliber bullet had a “comb” for coupling with the sectors of the pallet.
But experienced shooting showed that the natural drawbacks of the sub-caliber scheme are also inherent in this variant, and that it was not possible to solve only a change in their size: the killer action of 4,5-mm arrow-shaped bullets was significantly inferior to the standard cartridge LPS bullets; The accuracy of shooting single shots in linear characteristics was 2-2,5 times worse than the standard. If we add to this the need to develop technologies for the manufacture of all elements of the cartridge suitable for mass production, as well as the task of developing tracer bullets, it becomes clear that the huge amount of work that was to be performed.
The further history of domestic work in this area, which lasted up to 1983, is extensive and multifaceted. A detailed description of all the works would require too large a volume, so we confine ourselves to only the most fundamental points, without strict adherence to the chronology of events.
Throughout the initial phase, repeated attempts were made to use various types and brands of plastics for the pallets sector. But they all did not meet the requirements, while respecting the adequate size and weight of the pallet sectors. So far in the 1970 year, at the initiative of the cartridge manufacturers, no connection was established with the Vladimir Scientific Research Institute of Synthetic Resins, where a new type of plastics, Phenilon-S, was developed. As a result, the pallet sector began to be made from it. A technology has been developed for casting finished sectors of pallets, suitable for use in automatic rotary lines in the industrial manufacture of cartridges. The next photo on the left shows the sectors of “old” pallets made of D16T alloy, in their final design with plastic bands. The right side shows the finished plastic sectors of the pallets, obtained directly by casting and not requiring further processing.
Technologically the most time consuming and responsible was the production of arrow-shaped bullets with a given accuracy. Here it should be noted that the rumors about the alleged jewelry requirements for the accuracy of manufacturing arrow-shaped bullets are incorrect. In fact, tolerance fields, according to the requirements of the drawing, were quite typical. For artillery BOPS, for example, similar requirements are much stricter, despite the significantly larger dimensions of projectile elements and pallets sectors. In the course of the work, various methods and techniques for manufacturing arrow-shaped bullets were investigated. The following photo shows samples of their semi-finished products obtained in different ways.
On the left - with a deep hole in the tail (tracer bullet version) was completely obtained by cold stamping. In the middle - the head part is obtained by radial cutting. Right - rotational forging according to the technology used in the manufacture of industrial sewing needles. Later, in the Tula Polytechnic Institute, the development of an original radial-stamping device (PDH) for the press, used at the enterprises of the industry, which was characterized by increased productivity with the required manufacturing accuracy, was completed. What, in principle, finally decided the issue of mass production of arrow-shaped bullets. For this work, the team that included employees of the TPI and TsNIITOCHMASH, in 1987, was awarded the prize to them. S.I. Mosin.
But the most significant and important were the studies on the very "natural flaws" of the sub-caliber scheme, without the solution of which everything else did not make much sense.
Fundamentally improve the damaging effect was due to the design of the bullet. On its head part, they performed a flat, thus ensuring its asymmetry and, accordingly, the occurrence of an overturning moment when a bullet was inserted into dense tissues. On the body of the boom, in the area of the comb, a weakening element was made — a transverse groove or a groove along which the boom was bent under the action of this tipping moment. According to the results of the subsequent ground tests, the 4,5-mm arrow-shaped bullets modified in this way showed the best or equivalent with LPS bullets a striking and stopping effect. The penetrative and penetrating effect of swept bullets never raised questions and met the requirements, exceeding the standard ones.
The most difficult task was to work out the accuracy of shooting to the level of a regular rifle cartridge with an LPS bullet. The main reasons for the large dispersion to the designers were clear. These are the negative effects of the sectors of the pallets that separate from the boom as they leave the bore and increase the nutation angles of the booms when departing from the bore. At one time in the course of the work, it seemed that the optimal solution was found: an experimental version of a sub-caliber bullet with a plastic tail consistently showed good results, with a margin of compliance with the accuracy of 100 and 300 meters.
But when shooting at long ranges, it suddenly turned out that there was a significant and unstable increase in the bullet flight time, and the holes in the shield were unacceptably oval. What was unacceptable and indicated a significant deterioration in the shape factor. The reasons, of course, found. They turned out to be different and complex. The persistent search for a solution did not lead to success, and we had to return to working out the version with steel tails. In 1981, 10 / 4,5-mm cartridges 19VLG batches of OP 02-81-61 and OP 03-81-61 (for ground tests) when passing to OTK TsNIITOCHMASH showed accuracy of shooting at 300 m using a ballistic line on the ballistic line on the ballistic line, using the wrist line, using the wrist line, using the wrist line, this is the target of the ballistic line on the ballistic line, using the wrist line, it is the target of the ballistic line on the ballistic line on the ballistic line on the ballistic line, and it is using the ballistic line on the ballistic line and it’s up to the ballist to get out of the way for the ballistic line on the ballistic line on the ballistic line on the ballistic line of the wrist line, this is the case for the ballistic line, and the body of the ballistic line on the ballistic line on the ballistic line on the ballistic line on the ballistic section of the ballistic line, this is the target for the X-ray bar and the 50-mm. = 8,8 and 8,9 cm, respectively (with the standard R50, р 9,0 cm).
Of course, it was the best that the developers could produce by that moment, but the desired and so desired result was nevertheless achieved. And he was not accidental.
The ending should ...
© Nikolai Dvoryaninov, December 2017.
Photos and drawings: Nikolay Dvoryaninov.
Published: Magazine "Kalashnikov", №12 / 2017.
© Nikolai Dvoryaninov, December 2017.
Photos and drawings: Nikolay Dvoryaninov.
Published: Magazine "Kalashnikov", №12 / 2017.