Meanwhile, the traditional pistol cartridges, including those of the 9x19 type, which are in service in many countries of the world, no longer fully meet modern requirements for a combination of stopping and stopping action. The wide distribution of individual armor protection (SIBZ) made it necessary to qualitatively enhance the penetrating ability of bullets, without reducing their stopping quality. Of course, the potential of the widely used types of pistol cartridges is far from exhausted - this is evidenced by at least the development of Russian designers of rifle ammunition. But over the past two decades, a number of samples of small-sized automatic weapons of a new type have appeared. They are smaller than assault rifles, machine guns, carbines and more powerful than "traditional" pistols and submachine guns. And before adopting and mass production only a handful of units were brought.
It is clear that the search is based on the choice of cartridge. And here you can see two directions: more powerful pistol cartridges of “traditional” calibers and small-caliber ones, occupying, as it were, an intermediate position between pistol and submachine-based ammunition.
Klimov product
In 1996, a powerful 9-mm CP1 pistol with SP10 cartridge was adopted by the Federal Security Service of the Russian Federation. Both of them are the development of an experimental complex, which included an 9-mm cartridge РГ052 of type 9Х21 and a РГ055 pistol of the P.I. system. Serdyukov. The increased-power ammunition and weapons for it were created by the employees of the Central Research Institute of Precision Engineering (TsNIITOCHMASH) in the town of Klimovsk near Moscow as part of the development work on a new combat pistol on the subject of “Grach” (later, an armament of the Russian army).

Trial operation of pistols began in 1993 in the special forces units of law enforcement agencies. At the same time, the Ministry of Security of the Russian Federation (later the FSB) issued an order for the development of a new pistol (code "Vector") and a small-sized submachine gun. It should be noted that the possibility of creating a submachine gun was assumed at the beginning of the design of the new pistol complex with the cartridge 9х21. Now this idea took shape in the form of experimental design work under the code "Heather." The improved cartridge received the designation SP10, the pistol ordered by Lubyanka - CP1, the submachine gun - CP2 (the abbreviation "CP" means "special development", "SP" - "special cartridge").
The development of the machine gun CP2 "Heather" in TsNIITOCHMASH finished by the middle of 1998 year, and in 2000-m adopted.
The sample is arranged according to the scheme with the combination of the magazine slot and the pistol grip control. The main features of the submachine gun: rare for this class of weapons automation system and the node locking the barrel by turning the shutter. Removal of powder gases is produced through a transverse hole in the wall of the barrel into the gas chamber located above the barrel. In automation, the leading element is the bolt carrier rigidly connected with the gas piston rod. The shutter has six lugs. The return spring is located in the channel of the bolt carrier. The design of the moving parts of the automation and the percussion mechanism is similar to the fact that earlier in TsNIITOCHMASH they used in the development of AS and SR3 automata.
On the right side there is a folding reloading handle - this allowed to reduce the cross-envelope of the weapon. A compensator is attached to the muzzle of the barrel. The automatic box and its hinged hinged lid are cold-stamped from steel sheet.
Impact mechanism - impact type. The checkbox of the manual fuse is located on the right side, when turned on, the fuse blocks the descent, and its flag blocks the slot for the reloading handle. A separate flag translator is placed on the left side and sets a single and automatic fire, the translator flag is available for the thumb holding the weapon.
Meals are supplied from a direct box-shaped detachable magazine with a staggered arrangement of cartridges. When the ammunition is consumed, the store feeder rests against the bolt, which contributes to the ejection of the store after pressing its latch. It is two-sided, which allows for a quick replacement of the magazine when shooting with the right or left hand.

Tactical and technical characteristics of the machine gun CP2M
Cartridge 9x21
Mass of weapon (kg):
–Without ammo and collimator sight 1,65
–Collimator sight KP-CP2 0,3
The length of the weapon with the butt folded (mm) 603
Weapon length with folded butt (mm) 350
Barrel length (mm) 174
Number of cuts 6
Initial bullet speed (m / s):
- when firing the cartridge SP10 440
- when firing the cartridge SP11 415
- when firing 7BTZ 430 chuck
Rate of fire (rds / min) 900
Shooting Range (m) 200
20 or 30 magazine capacity
The bullet of the SP10 cartridge with a heat strengthened core protruding from the shell reliably hits targets in SIBZ of the second and third protection classes or in unarmored cars. In addition to SP10, SP11 cartridges with a low-skull bullet, 7BT3 with an armor-piercing tracer bullet can be used.
Fly with a fuse installed at the muzzle of the barrel. The sight of a mechanical sight is designed for 100 and 200 meters firing range. With the help of a bracket on the lid of the automatic box, a KP-CP2 collimator sight can be mounted with a 6 field of view. It should be noted that the collimator shooting sights, allowing you to quickly combine the aiming mark with the aim and aim the weapon, leaving both eyes open, are considered by a number of specialists as the main ones when conducting short-term combat at short range.
The butt of the weapon is metal stamped, folding up and down with folding shoulder rest. The pistol grip and handguard are made of impact-resistant plastic, the pistol grip is made integral with the trigger guard, the foregrip covers the barrel, the front stop is installed in front of it. The front bend of the trigger guard is designed for firing from outstretched arms, like shooting from a two-handed grip pistol.
The submachine gun was upgraded. At SR2M on the fore-end, instead of a hard stop, a folding front handle appeared, which improves the controllability of the weapon and accuracy of shooting. In the folded position, the handle becomes part of the forearm. Changed the fuse box slightly. In addition, the weapon received a different muzzle device - now it is not a muzzle brake compensator, but a muzzle-abutment that protects the hand of the arrow from moving forward and burns with powder gases.
"Heather" is worn openly on a belt or covertly, on the case with the use of a suspension that holds the weapon itself and a spare magazine.
German version
Among the most popular themes of the development of "military" and "police" small arms abroad in 1990 – 2000-ies can be called the “personal defense weapon” (Personal Defense Weapon). The term is rather arbitrary and widely interpreted, but, as a rule, it is understood as a small-sized sample, designed for firing single shots and bursts at short distances, not too burdensome to the owner when carrying and reliably striking from the first shot or the enemy's turn - even if SIBZ or he is behind cover.
Designers of the German company "Heckler und Koch" approached this type of weapon several times and with varying success. In 2000, the company introduced a model that received the designation “MP7 submachine gun” and has since proven itself well.

Tactical and technical characteristics of the MP7 PDW submachine gun
Cartridge 4,6x30
The mass of weapons with unsupported 20-local shop (kg) 1,2
The length of the weapon with the butt removed (mm) 340
The length of the weapon with extended butt (mm) 540
Barrel length (mm) 180
Initial bullet speed (m / s) 725
Shooting Range (m) 200
Rate of fire (rds / min) 950
20 or 40 magazine capacity
To begin with, a new cartridge 4,6x30 was developed. In the creation of ammunition, which would maintain at short distances the dignity of an automaton with the mass and pressure in the barrel, comparable with the powerful pistol cartridge, the Germans were not the first. At the end of the 1980s, the Belgian "Factories Nacional" designed an original machine gun - or a submachine gun, if you like - P90 chambered for SS190 (5,7x28). Р90 then aroused wide interest, but, despite optimistic forecasts, it did not find wide distribution. Bought it in small quantities. Nevertheless, the German company also took the path of creating a whole new weapons complex, including a new ammunition.
The cartridge 4,6X30 RUAG- “Amotech” is equipped with a pointed bullet with a small flat platform at the tip. With an initial speed of 725 m / s and a mass of 1,6 grams, the bullet with a steel core and copper shells allegedly pierces a distance of 200-mm titanium plate and 1,6 Kevlar layers behind it within the range of aimed fire. This complies with the CRISAT protection standard and 20 – 1 class according to the national standard. The flatness of the trajectory, due to the high speed of the bullet, contributes to an increase in accuracy, although the effective range of shooting is unlikely to exceed 2 meters.
In developing the weapons themselves, the Germans also resorted to automation with a gas engine and rigid locking of the barrel. In the constructive design of the relevant mechanisms in the "Heckler und Koch" they decided not to be too original, combining the already found solutions. The MP7 PDW is arranged according to a scheme with the combination of the magazine slot with the pistol grip control - this did not increase its dimensions too much, since the length of the cartridge is 38 millimeters.
The removal of powder gases occurs through the side opening in the wall of the barrel. Locking its channel by turning the shutter. The reflector of a sleeve is mounted in a lock. The design of parts for automation and locking unit MP7 used the experience of developing an assault rifle G36 of the same company, but the details of these two samples are not interchangeable. Automation works differently, in particular, the piston and pusher of the MP7 are combined, in contrast to the G36. There is a shock absorber to mitigate the impact of the moving system in the rear position.
The barrel is made by cold forging. In its muzzle part there is a thread for fastening the flame arrester and a hole for fixing the muffler. The receiver is assembled from plastic parts. To better protect the mechanisms from contamination and reduce the transverse dimension, the T-shaped rear reloading handle is used; it remains stationary when fired. Bilateral flag translator-fuse sets the modes of single and automatic fire. A check mark is available for the shooting hand thumb.
The weapon is equipped with a retractable butt and folding front handle, in the folded position playing the role of the forearm. The trigger guard is designed for shooting in tight gloves.
Meals are supplied from a detachable box-shaped double-row magazine for 20 cartridges (the magazine for 40 cartridges is also represented). The two-way lever of its latch is located behind the trigger guard.
MP7 A1 comes in two versions: KSK is designed for special forces, IDZ - for army units. The main difference is in sights. "Infantry" IDZ equipped with a fully open slot, spetsnaz KSK - reversible diopter sight. The low-profile mechanical sighting device is supplemented with a stepped strap of the Pikatini type for installing a collimator sight. The diopter on the MP7 A1 KSK makes it possible to use the RSA Hesoldt, Eympoynt, Eotech collimator sights with it, and aimed shooting can be done with night vision goggles. If necessary, a laser designator is placed on the same bar.
The 4,6x30 cartridge is equipped not only with a steel core bullet. There are variants of the same ammunition with a tracer and with a weighted bullets, having a subsonic initial speed. The weighted bullet is used in combination with the silencer of the Swiss firm Brugger and Tomet (weight 520 g), which is mounted directly on the flame arrester. If the fire is fired by high-speed bullets, the silencer serves as a low-noise firing device.
It is hardly necessary to attach great importance to the external similarity of the design of the described samples - СР2М and MP7 A1 - similar tasks inevitably lead to similar solutions.
Other developers have also created their own versions of small-caliber cartridges for the PDW's “short-range self-defense weapons”. We can mention, for example, the cartridge 6.5x25 CBJ-MS of the Swedish company CBJ Tech AB or 5,56х23 (.224 VOB) of the Czech “Luvo”. True, in contrast to the Belgian 5,7-mm and German 4,6-mm, these cartridges and weapon models under them remained experimental.