Probably, every person who is interested in the topic of weapons, had heard about the 9x21 pistol cartridge. This is a really good example of ammunition - one of the few developed in recent decades. Some experts do not even doubt that the future is behind this cartridge and in the coming years it will be able to displace the outdated 9x18, developed more than half a century ago.
History of creation
In the eighties, widespread in many major armies of the world began to receive body armor. They demonstrated their effectiveness and therefore entered the mandatory equipment of the military. Conventional cartridges 9x18 mm used by pistols and submachine guns were not effective against them.
Therefore, the Ministry of Defense decided to create a new ammunition capable of effectively piercing at least long-range bulletproof vests of the first or second defense classes at long range. As a result, in 1992, a 9x21 cartridge was developed. He quickly gained popularity, demonstrating the excellent penetration of light bulletproof vests. In total with high energy and a significant initial velocity of the bullet, this provided him with recognition - in the following years several weapons were quickly developed for a completely new ammunition.
Cartridge Features
As already mentioned, the new ammunition was created specifically to hit targets protected by bulletproof vests. However, as tests revealed, it was also effective in firing on cars and opponents who took refuge behind light shelters.
The dimensions of the 9x21 cartridge were very different from the usual 9x18, which was used as the basis for the development of the new ammunition. To start with at least the real caliber of the bullet - it was reduced from 9.27 mm to 9.05. In addition, the cartridge has become much longer - from 24.8 mm to 32.7. Thanks to this, it became possible to dramatically increase the energy of the bullet. The proven 9x18 ammunition at best showed an energy of 500 joules, while the new one reached 638. This turned out to be enough to penetrate bulletproof vests of the second class of defense at distances up to 100 meters! But even the powerful American cartridge.44 Magnum cannot do this.
In addition, a special bullet was used - it received a steel heat-strengthened core, characterized by increased penetration. So there was a cartridge SP-10. He was distinguished not only by excellent penetrative ability, but also by the small weight of the bullet - only 6.7 grams. This provided excellent flatness and the ability to take small corrections over long distances when firing a submachine gun.
Fight against ricochets
However, the increased power of the cartridge has led to a new problem. When shooting indoors, the probability of rebounds sharply increased. But pistols and submachine guns are most often used in rooms. How to shoot if a bullet, hitting an obstacle, can hit the shooter himself or a third person?
Especially for this case, a new ammunition was created - SP-11. In fact, this is the same cartridge 9x21 mm, but it had a softer bullet. The lead tip was deformed when hit in solid objects, which almost completely eliminated the possibility of rebounds. The bulletproof vests of the second class of protection could no longer penetrate such a cartridge, but it did very well with the first class. The use of lead led to the fact that the bullet gained more weight - 8 grams.
Expansive bullet
After checks, it turned out that the SP-11 cartridge, although it had very good performance, but lost its main initial plus. Therefore, it was decided to continue the work. It was not possible to return the penetration ability, while reducing the likelihood of rebounds. But an expansive SP-12 cartridge was created. It was also quite effective against the armor of the first class of defense, but when it hit the enemy’s body, it also opened. Thanks to this, two goals were achieved at once. On the one hand, the enemy received a really terrible wound that could lead to death even when hit in the arm or leg. On the other hand, the possibility of piercing his body with the subsequent injury of third parties was completely ruled out.
True, I had to work decently with this cartridge. At first it was decided to use just a half-bullet bullet. Later it was decided that the expansive cavity significantly increases the effect of the hit. But this brought another problem - the ballistics of the bullet changed dramatically. Despite the fact that the mass of the bullet returned to 6.7 grams, the change in shape led to the fact that the shooter had to take unique corrections each time when using different types of ammunition. Of course, this is unacceptable. As a result, the problem was solved - the bullet received a special plastic tip. This did not affect the weight, and due to the fact that the blunt cut was closed, the roundness of the bullet improved dramatically, so that the goal was achieved.
Ammunition weapons
Of course, immediately after the advent of the new cartridge, programs were launched to develop the appropriate weapon for him.
The first successful model was the legendary SR-1 "Gyurza", taken into service by special forces soldiers. It was developed in the period from 1993 to 1996 and was immediately adopted, put into production. Along with a number of other advantages, he had a store of huge capacity - as many as 18 rounds.
A few years later, the SR-2 Veresk appeared - a very successful submachine gun, which is compact and lightweight, but at the same time confidently hitting targets at a distance of up to 200 meters.
Finally, the last successful development taken into service was the Boa constrictor pistol, developed in 2016. Light weight, high sighting range and a magazine for 18 rounds made it an outstanding weapon.
It is important that this weapon can be perfectly used by any 9x21 cartridge - SP-10, SP-11, SP-12 and others.
Israeli IMI
Often speaking about the unusual caliber 9x21 mm, some experts say that it was developed in Israel in the mid-eighties. However, they confuse Russian development with the Israeli 9x21 IMI cartridge. Yes, such ammunition really exists.
However, the length of the cartridge is much smaller - only 29.75. And he cannot boast of outstanding armor-piercing abilities. In addition, the energy of a bullet ranges from 520 to 570 joules - depending on the weapon used. Recall that in the Russian 9x21 this figure reaches 635 joules. Israeli ammunition is produced mainly for export to Italy, where a 9x19 army cartridge is prohibited for use by civilian shooters.
