Vogue underbarrel grenade launcher. Cartridge container. Purpose of the main parts and mechanisms of the grenade launcher
Until 2005, unitary VOG-17 and VOG-ZO rounds with high-explosive fragmentation grenades were used to fire from 30-mm mounted anti-personnel grenade launchers AGS-17 and AGS-30 (Fig. 1, Fig. 2).
In the first VOG-17 grenade launcher round developed by FSUE SNPP "Basalt", the grenade consists of a chiselled thin-walled body, inside of which there is a fragmentation jacket in the form of a twisted and transversely notched steel spring of square section, as well as two blocks of explosive. Due to the design features of the hull, when it is detonated, many small fragments are formed, which make it possible to effectively hit unprotected manpower.
In the second generation VOG-ZO round, created by the Federal State Unitary Enterprise FSPC Pribor, the grenade body is made by cold deformation with the formation of semi-finished rectangular-shaped striking elements on the inner surface of the mesh. The use of a new housing design made it possible to press the explosive directly into the housing and thereby increase the filling factor by 1.1 times. Taken together, this ensured an increase in the effectiveness of fragmentation damage by more than 1.5 times.
The VOG-17 and VOG-ZO rounds are equipped with a head mechanical instantaneous fuse, semi-safety type, with a pyrotechnic mechanism for long-range cocking and self-destruction.
There are three modifications of grenade launcher rounds. The original and already obsolete type VOG-17 with an instantaneous fuse. The subsequent modification, VOG-17M, differs from the previous one in that the fuse is equipped with a self-destruct device. The self-destruct mechanism is activated by overloads when fired. Fuses of all types of grenades are cocked at a distance of 10-60 m from the muzzle of the grenade launcher, which provides additional safety when firing. For training shooting, practical VUS-17 rounds are used, equipped with a pyrotechnic composition of orange smoke, indicating the location of the grenade landing. The grenades of these shots are equipped with a copper leading belt pressed into the grenade body.
These shots meet strict Russian standards in all respects and are mass-produced. Despite the smaller caliber compared to some foreign grenades, the striking effectiveness of these shots is even higher (Fig. 3).
However, the maximum firing range of the AGS-17 and AGS-30 grenade launcher systems using VOG-17 and VOG-ZO rounds is 1730 m, which is significantly less than that of foreign grenade launcher systems.
In addition, over time, experts also began to note the insufficiently high fragmentation efficiency of VOG-17 and VOG-ZO ammunition when fighting manpower protected by constantly improving personal armor protection, as well as their large technical dispersion over range, amounting to Vd/Xmax ≤ 1 /70.
These shortcomings reduced the technical level of Russian grenade launcher systems, and consequently their competitiveness in the international arms market. Due to these circumstances, the issue of improving the main tactical and technical characteristics of the VOG-17 and VOG-ZO rounds at the end of 1999 became extremely urgent and required urgent decisions. A study of the design of the VOG-17 and VOG-ZO rounds showed that their combat capabilities within the framework of existing designs have largely been exhausted. It became obvious that it was possible to increase the firing capabilities of grenade launchers and expand the range of tasks with their use through the development and adoption of more powerful multi-purpose high-explosive fragmentation ammunition.
Based on the trend in the global development of ammunition and the conditions of modern combat, according to military experts, for these complexes it was necessary:
Increasing the maximum firing range from 1730 m to at least 2100 m;
Improved combat accuracy Vd/Xmax from 1/70 to 1/100;
An increase, in comparison with a standard VOG-ZO shot, is ≈ 1.3 times the area of fragmentation destruction of unprotected manpower, as well as manpower in body armor with a specific penetration energy of 62 kg/cm2.
Due to these circumstances, in 1999, the State Unitary Enterprise "Instrument Engineering Design Bureau" began work on creating a new 30-mm GPD-30 round with a high-explosive fragmentation grenade of increased efficiency for the AGS-17 and AGS-30 grenade launchers in service.
It was obvious that it was not possible to significantly increase the maximum firing range in the traditional way, that is, by increasing the lateral load of the grenade and its initial speed, since standard grenade launchers are designed for a certain recoil impulse.
The existing experience in solving such issues clearly indicated that it is possible to increase the firing range while maintaining recoil momentum only by improving the aerodynamic shape of the grenade. Achieving better performance in terms of combat accuracy is possible only by increasing the accuracy of guiding a grenade along the barrel, reducing the spread of its initial speed, ballistic coefficient and center of mass imbalance, which together allows the grenade to leave the barrel with minimal disturbance and more accurately reach the intended target.
The task of increasing the lethality of the grenade turned out to be no less difficult.
The task of increasing the area of fragmentation destruction of manpower, including those protected by body armor, was solved comprehensively, namely, by optimizing the average mass of fragments, increasing their speed and angles of expansion, using a grenade in larger quantities and with a stronger high-explosive effect of explosive substances.
For the new shot, a new method of manufacturing the grenade body has been developed. In this case, it is manufactured, like the body of the VOG-ZO grenade, by the method of volumetric deformation on its inner surface of a fragmentation mesh of a rhombic profile, in which all sides of an individual fragmentation element are oriented relative to the texture of the cold-worked body at a certain angle. It was the absence of longitudinal stress concentrators in the fragmentation network that excluded the destruction of the hull along its generatrix, and, consequently, the formation of large and “saber-shaped” fragments, which reduced the utilization rate of the hull metal.
The uniqueness of the noted technology lies in the fact that it allows only two operations and without relative axial displacement of the forming tool and the body blank to completely produce a fragmentation mesh. This ensures high durability of the tool and maintains for a long time the original accuracy of the geometry of the riffles, which are responsible for the destruction of the body in strict accordance with the number of semi-finished elements embedded in the fragmentation mesh.
The end result of the work done was the adoption in 2005 of the Ministry of Internal Affairs of the Russian Federation of a modern 30-mm grenade launcher with a high-explosive fragmentation grenade of increased efficiency (Fig. 4, Fig. 5).
The grenade launcher device is shown in Figure 6.
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Rice. 6. Design of the GPD-30 grenade |
The shot works as follows.
When the primer is initiated, the propellant charge located in the bottom recess is ignited. The resulting powder gases flow through transverse channels into the external cavity, thereby equalizing the pressure on both sides of the wall of the hollow stern. Taking into account the fact that the end part of the stern is limited by the bottom side surface of the liner, the volume of the external cavity is significantly less than the volume of the charging chamber, and the flow area of the transverse channels has a very definite value, the increase in pressure in both volumes occurs almost simultaneously and without residual deformation of the stern wall.
After the powder gases reach the so-called forcing pressure, the grenade is pressed initially by its leading belt into the bullet entrance, and then into the side edge of the rifling of the barrel bore, forming leading protrusions on the belt in a shape that corresponds to the rifling of the barrel bore. The belt material displaced by the rifling field is freely placed in the depressions of the comb belt, thereby providing the necessary condition for the grenade to fly out of the barrel with minimal disturbances, and therefore the possibility of providing a greater firing range. When the grenade reaches the muzzle of the barrel, it leaves the latter with a given linear and angular velocity. In flight, a rotating grenade captures air with its intake planes 16 of its transverse grooves 10 and thus creates additional resistance forces at its end, causing the appearance of a lifting force and an additional stabilizing pitch moment relative to the center of mass of the grenade located upstream of the air flow. As a result of this, the nutational vibrations of the grenade are damped, thereby reducing its drag, which helps to increase the flight range.
When the grenade reaches the target, the sharp deceleration triggers the head fuse 17, causing the detonation of the explosive 18 and, as a consequence, the destruction of the grenade body and the formation of a high-speed flow of destructive elements.
The rationality of the distinctive features of the third generation GPD-30 shot in comparison with the second generation VOG-ZO shot is confirmed by the graphical dependencies shown in Figures 7-12.
A comparative analysis of the presented graphs shows that the use of the GPD-30 round instead of the VOG-ZO round allows:
Increase the maximum firing range by 21.4% by reducing the drop in speed during flight;
Increase the altitude by 16% when firing flat and mounted trajectories;
Reduce the sensitivity of the grenade trajectory to the action of side winds by 1.5-2 times both during flat and mounted shooting;
Reduce the sensitivity of the firing range to the action of longitudinal wind by 1.5-2 times when firing at throwing angles of up to 40°.
At the same time, the flight time of the grenade is reduced by up to 40% during flat firing at a distance of up to 1730 m and increases slightly during mounted firing due to an increase in the trajectory height.
The appearance of fragments distributed among mass groups is presented in Figure 13 and indicates the planned fragmentation of the grenade shell.
To numerically assess the superiority of the GPD-30 grenade over the VOG-ZO grenade, the reduced area of fragmentation damage within their maximum firing range was calculated.
The results of calculating the reduced area of damage by fragments of a given fragmentation of GPD-30 and VOG-ZO grenades depending on the firing range (the angle of approach of the grenade to the target) are shown in Figure 15.
As you can see, in terms of the area of the reduced fragmentation damage of the GPD-30 grenade, in the entire range of firing ranges it significantly exceeds the standard VOG-ZO grenade.
Based on experimental data assessing the maximum firing range, combat accuracy and reduced area of fragmentation damage of GPD-30 and VOG-ZO rounds, as well as calculating the effectiveness of their combat use, the superiority of the new development in all main and auxiliary parameters is shown (Fig. 16).
The high level of technical and economic indicators of the GPD-30 shot allowed the State Unitary Enterprise "Instrument Engineering Design Bureau" to organize its mass production in the shortest possible time and at minimal cost. Since 2005, the GPD-30 round has been exported.
The 40-mm VOG-25 (7P17) shot is unitary in design and is made according to a “caseless” design, i.e. The propellant charge together with the ignition agent is located in the bottom part of the grenade body. This is the first time such a shot pattern has been used in domestic practice. It made it possible to greatly simplify the design of the grenade launcher and, accordingly, increase the reliability of the weapon, coupled with an increase in the combat rate of fire. The shot grenade is a fragmentation grenade with a steel body. Inside the grenade body (between the bursting charge and the body) there is a cardboard mesh for rational crushing of the body into fragments, which helps to increase the fragmentation effect. Here it is simply necessary to note that the VOG-25 round grenade is 1.5 times more powerful at the target than the 30-mm OFZ round for the 2A42 cannon, which is equipped with the BMP-2.
The outside of the grenade body has ready-made rifling, which serves to give the grenade a rotational movement (the grenade is stabilized in flight due to rotation) as it moves along the barrel. The grenade fuse (index VMG-K) is a head, impact, instantaneous and inertial action, semi-safety type with pyrotechnic long-range cocking and self-liquidator. The cocking distance is from 10 to 40 meters from the muzzle of the grenade launcher. Such a significant spread is due to the temperature range of use of the weapon (from minus 40°C to 50°C). The response time of the self-destruction mechanism is 14–19 seconds.
In 1978, comparative tests of the GP-25 grenade launcher with the VOG-25 round and the 40-mm M-203 under-barrel grenade launcher mounted on the M16A1 rifle with the M-406 round were carried out. Tests have shown a significant advantage of the domestic grenade launcher and its shot over a similar system produced in the USA. The VOG-25 and M-406 shots were compared by firing at an area where a target environment was located, simulating openly located manpower (lying growth targets). During these tests, it was revealed that the frequency of hitting targets on the tactical field from the explosion of a grenade from a VOG-25 shot is 3–4 times higher than from the explosion of a fragmentation grenade from an M-406 shot.
While the designers from TsKIB SOO were designing the GP-25 grenade launcher, namely in 1974, their colleagues from the Pribor State Research and Production Enterprise were given a new task. It was necessary to develop a new 40-mm shot for an under-barrel grenade launcher with increased fragmentation efficiency against manpower lying down and in unprotected shelters from above (trenches, trenches, stones, etc.), compared to the VOG-25 shot grenade, 1 .5–2 times (without reducing the effectiveness of fragmentation against growth targets). This, frankly speaking, difficult technical problem was brilliantly solved by the team of designers from the Pribor State Research and Production Enterprise. In 1979, a new 40-mm shot with the VOG-25P fragmentation grenade was presented for field testing (
“Foundling”, index 7P24) and in the same year the new shot was recommended for service with the SA. The main and main difference of the new shot was the head fuse, which received the VMG-P index.
An expelling charge and a pyrotechnic moderator were introduced into the design of the VMG-P fuse, ensuring that the grenade “bounces” after hitting the ground and explodes in the air when fired at all combat ranges of the grenade launcher. The height of the grenade burst when fired at medium-hard soil was 0.75 m, which made it possible to increase the effectiveness of the fragmentation action in comparison with the VOG-25 shot grenade.
Caliber 40 mm
Shot weight 250 g
BB weight 48 g
Shot length 103 mm
Initial grenade speed 76 m/s
The self-destruction time of the grenade is at least 14 seconds.
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VOG-25 grenade launcher shot (GRAU Index - 7P17) is fragmentation ammunition for under-barrel grenade launchers of small arms and is intended to destroy enemy personnel.
The VOG-25 shot was developed at the Moscow Pribor design bureau in the 70s of the twentieth century for the GP-25 under-barrel grenade launcher.
Unlike the Americans, Soviet designers decided to create a shot (a grenade with a starting charge) of a fundamentally new design - with a “flying away” cartridge case.
In the VOG-25 shot, the chamber for the propelling powder charge was located directly on the grenade. As a result, there was no need for such an operation as the extraction of a spent cartridge case. After the shot, the shooter must only take out the next grenade from the bag, insert it into the muzzle of the grenade launcher and push it all the way into the barrel. Moreover, this operation is performed with one hand.
The VOG-25 fragmentation shot combines a grenade and a propellant charge in a cartridge case.
The 40-mm VOG-25 shot in the middle part has a belt with 12 leading protrusions that fit into the rifling and give the grenade rotation during the firing process. Some breakthrough of powder gases that occurs with such a device is acceptable for short-barreled weapons with a low initial projectile velocity, a small propellant charge and a barrel length almost equal to the length of the shot. A similar design of projectiles for muzzle-loading rifled weapons is not new (the grenade for the Dyakonov rifled grenade launcher had three leading protrusions), but it is quite effective.
The fairing gives the grenade an ogival shape, ensuring proper flight.
Inside the grenade body (between the bursting charge and the body) there is a cardboard mesh for rational crushing of the body into fragments, which helps to increase the fragmentation effect. Here it is simply necessary to note that the VOG-25 round grenade is 1.5 times more powerful at the target than the 30-mm OFZ round for the 2A42 cannon, which is equipped with the BMP-2.
The problem of removing the spent cartridge case, which is rigidly connected to the grenade, is also ingeniously solved in VOG25. When the propellant charge burns, powder gases enter the breech of the grenade launcher through special holes, ejecting the grenade from the barrel, and with it the cartridge case. Given the light weight of the cartridge case, this does not negatively affect the ballistics of the grenade.
The burning of the charge while the grenade moves along the barrel somewhat softens the recoil of the weapon.
The grenade fuse (index VMG-K) is a head, impact, instantaneous and inertial action, semi-safety type with pyrotechnic long-range cocking and self-liquidator. The cocking distance is from 10 to 40 meters from the muzzle of the grenade launcher. Such a significant spread is due to the temperature range of use of the weapon (from -40°C to +50°C).
The fuse is unified with the 30-mm VOG-17 round from the AGS-17 grenade launcher.
In case the fuse fails or falls into water or viscous soil, the grenade has a self-liquidator that fires 14-19 seconds after the shot.
VOG-25 has a mass of 255 g and a total length of 106.7 mm. The initial speed of a fragmentation grenade is 76 m/s. The radius of continuous destruction by fragments when a grenade falls vertically reaches 10 m.
VOG-25 shot device:
40-mm shot VOG-25:
a - general appearance and markings; b - section;
1 - fuse; 2 - fairing; 3- gaskets; 4-cardboard mesh;
5-grenade body, 6-explosive explosive charge; 7-bottom grenade;
8-powder propellant charge
The VOG-25 shot is unitary in design. It consists of a grenade with a fuse screwed into the head of the body and a propellant charge into the bottom. A fairing is installed on the grenade body.
The grenade consists of a body, a bottom, a bursting charge, a mesh and gaskets.
The body of the grenade has a cylindrical shape, is made of steel and is designed to mount all parts of the shot, impart translational and rotational motion to the grenade in the barrel bore and produce fragments when the grenade explodes. On both sides of the body there is an internal thread for installing the fuse and the bottom. Design options are possible when the bottom is connected to the body by a press fit.
The bottom serves to attach the propellant charge and fix the grenade in the grenade launcher barrel after loading.
A cylindrical explosive explosive charge is designed to break the body into fragments and give them a certain dispersion speed. The explosive charge is pressed into the grenade body with gaskets.
The mesh is made of cardboard. It is designed to obtain organized crushing of the body into fragments.
The fairing is mounted on the grenade body and serves to reduce the influence of air resistance.
The powder propellant charge is designed to impart initial speed to the grenade. It consists of a cartridge case in which a powder charge and an igniter primer are placed. The powder charge is closed with a ring and a lid made of aluminum foil.
VMG-K fuze
1 - cover; 2 - gasket; 3, 19, 21, 22, 26, 27, 29, 36 - caps;
4- plate; 5, 39 - stings; 6, 25, 31, 35, 38 - springs; 7 - liner;
8 - nut; 9, 15, 32 - detonator caps; 10 - damper;
11, 17 - bushings; 12 - body; 13 - powder composition; 14 - gasket;
16 - nut; 18 - powder composition; 20 - spring; 23 - gasket;
24 - stopper; 28 - screw; 30 - spring ring; 33 - gear
powder composition; 34 - pin; 37 - igniter primer;
40 - igniter composition.
The VMG-K fuse is designed to detonate the explosive charge of a grenade. The fuse is a head fuse, instantaneous and inertial action, semi-safety type, with pyrotechnic long-range arming and self-destruction. The fuse is safe in service handling, during transportation, shooting and in flight before arming, when dropped from a height of up to 3 m on any base in any position.
It consists of impact and ignition mechanisms, a long-range cocking safety mechanism, and a self-destruction mechanism.
The impact mechanism is designed to transmit the reaction force of the target and ensure the activation of the fuse fire chain. It consists of a cover 1, a screw 28, a cap 3, two plates 4 resting on a tip 5, pressed by a spring 6, and a cap 27, assembled in an insert 7.
The ignition mechanism, which ensures the launch of the long-range cocking safety mechanism, consists of an igniter primer 37, a spring 38, a tip 39, fixed by punching in the sleeve 11.
The long-range cocking safety mechanism, which ensures the safety of the fuse in use, consists of a sleeve 17 with a pressed powder composition 18, a cap 19, a spring 20, caps 21, 22, a gasket 23, a stopper 24 that holds the damper 10 with a spring 25 from moving to the side position. The damper contains a highly sensitive detonator cap 9 of the pin type.
The safety-centrifugal mechanism, which keeps the valve from moving into the firing position, consists of a pin 34, a spring 35 and a cap 36, located in the sleeve 11.
The self-destruction mechanism, designed to destroy a grenade in the event of a failure when meeting an obstacle, consists of a sleeve 11 with a powder composition 13 pressed into it along an annular path, an ignition composition 40 and a transfer powder composition 33 and a detonator capsule 32, secured by punching in the sleeve 11 .
The fuse mechanisms are located in the housing 12 on the gasket 14 and are pressed through the cap 26 with a nut 8 with gasket 2. In the rear part of the housing there is a detonator capsule 15, secured with a nut 16.
In 1978, comparative tests of the GP-25 grenade launcher with the VOG-25 round and the 40-mm M-203 under-barrel grenade launcher mounted on the M16A1 rifle with the M-406 round were carried out. The VOG-25 and M-406 shots were compared by firing at an area where a target environment was located, simulating openly located manpower (lying growth targets). During these tests, it was revealed that the frequency of hitting targets on the tactical field from the explosion of a grenade from a VOG-25 round is 3-4 times higher than from the explosion of a fragmentation grenade from an M-406 round.
For training, VOG-25IN rounds (GRAU Index - 7P17I) with an inert grenade or a 7P44U practical round, which can also be used for target designation, are used. To do this, there is a smoke charge, which lasts for 10–15 s. generates a cloud of red-orange smoke. Their ballistics are consistent with live grenades.
While the designers from TsKIB SOO were designing the GP-25 grenade launcher, namely in 1974, their colleagues from the Pribor State Research and Production Enterprise were given a new task. It was necessary to develop a new 40-mm shot for an under-barrel grenade launcher with increased fragmentation efficiency against manpower lying down and in unprotected shelters from above (trenches, trenches, stones, etc.), compared to the VOG-25 shot grenade, 1 .5-2 times (without reducing the effectiveness of fragmentation against growth targets). This difficult technical problem was brilliantly solved by the team of designers from the Pribor State Research and Production Enterprise. In 1979, a new 40-mm shot with a fragmentation grenade VOG-25P (“Foundling”, index 7P24) was presented for field testing, and in the same year the new shot was recommended for service with the Soviet Army. The main and main difference of the new shot was the head fuse, which received the VMG-P index.
An expelling charge and a pyrotechnic moderator were introduced into the design of the VMG-P fuse, ensuring that the grenade “bounces” after hitting the ground and explodes in the air when fired at all combat ranges of the grenade launcher. The height of the grenade explosion when firing at medium-hard soil was 0.75 m, which made it possible to increase the effectiveness of the fragmentation effect in comparison with the VOG-25 grenade: against lying targets by 1.7 times; on targets located in the trench 2 times.
Attempts to create a fragmentation-cumulative round during the development of the “grenade launcher” turned out to be unsuccessful in terms of ballistics.
In addition to the army, the GP-25 grenade launcher was also adopted by the internal troops of the Ministry of Internal Affairs. This caused changes in the grenade launcher's ammunition load. In particular, the “Nail” shot was developed with a gas grenade filled with the irritating toxic substance CS.
The weight of the "Nail" grenade is 170 g, the maximum firing range is 250 m, the minimum permissible is 50 m, the gas release time is up to 15 s, the volume of the formed cloud is 500 cubic meters.
In addition, for special operations of law enforcement units, grenade launchers with smoke, light-sound and thermobaric grenades were created.
Loading a shot. The grenade is fed into the grenade launcher until
characteristic click: the trigger is brought into firing position.
In the early 2000s, the Pribor State Research and Production Enterprise developed modernized VOG-25M and VOG-25PM rounds to replace the VOG-25 and VOG-25P rounds. They have a new unified body with organized crushing during detonation. The number and energy of the resulting fragments provide a 1.5 times greater probability of hitting living targets.
The grenade launcher is loaded with a VOG-25 shot from the muzzle of the barrel. A 40-mm caliber grenade is inserted into the barrel without effort. The shot must be inserted into the barrel until it stops at the end of the breech. In this case, the shot in the grenade launcher barrel is fixed by a special lock, which, in turn, is connected to a transfer lever that blocks the trigger in such a way that if the shot is not fully fired, firing becomes impossible.
To remove an unused shot, click on
eject button. The grenade partially comes out of the barrel,
The grenade launcher trigger is deactivated.
A dangerous element of underbarrel grenade launchers is the fuse, which is highly sensitive to impact. It is prohibited to disassemble the grenade and fuse. It should be borne in mind that the self-destructor of a failed grenade can be triggered by accidental (even small) movement of the failed grenade, and about 30-40 seconds will pass from the moment the grenade is moved to the explosion.
It is strictly forbidden to touch unexploded grenades after firing. These grenades must be destroyed at the site of their fall, taking appropriate precautions.
Ammunition of 10 shots is carried by the shooter in a “bag”, which is two fabric cassettes with sockets for shots, 5 in each. Cassettes are located on belts on both sides of the shooter's body, so shots are available no matter what position the shooter is in. Unloading vests can also have special pockets for GP-25 rounds. In addition, new equipment has been created for carrying ammunition: two pouches with five pockets for shots are placed horizontally on the stomach and chest and serve as additional body protection.
VOG-25 rounds are also used in other weapon systems: the OTs-14 “Groza” assault rifle-grenade launcher system, the RG-6 six-barreled revolver grenade launcher and the single-shot RG-1.
- Ammunition » Shots » Russia / USSR
- Mercenary 63018 0
40-mm active shots VOG-25, VOG-25P (bouncing) with a fragmentation grenade are designed to destroy enemy personnel located in open areas, reverse slopes, in trenches, trenches at ranges of up to 400 m. The design feature of the shot is a two-chamber ballistic engine (DBK) and organized fragmentation. Firing is carried out from 40-mm under-barrel grenade launchers GP-25, GP-30, installed on all modifications of the Kalashnikov assault rifle (except for the shortened AKS-74U). Loading is done by inserting a shot into the barrel from the muzzle until the latch clicks. For practice shooting and testing the combat of grenade launchers, VOG-25in rounds with an inert grenade (filled with a smoke-forming or inert substance instead of BB) and a mock-up fuse are used.
The 40-mm VOG-25 shot consists of the following main parts:
- fragmentation grenade OG-25;
- propellant charge 4A-33;
- instant action fuse of the head VMG-K.
The OG-25 fragmentation grenade has:
- steel body with fairing;
- explosive charge - round block BB brand A-IX-I;
- cardboard insert - mesh;
- bottom with flange and tray.
The grenade body is made with internal threads on both sides for attaching the fuse and the bottom and has 12 ready-made lugs for barrel rifling, 8 transverse grooves to facilitate fragmentation. The fairing, which completely covers the fuse, is attached to the body by rolling. The cardboard mesh insert ensures organized crushing of the body into lethal fragments (up to 200 lethal fragments), due to the difference in the speed of propagation of the explosive transformation in different environments. The bottom has a flange for fixing the grenade in the barrel and a tray with internal threads for screwing in the propellant cartridge case. The bottom can be attached to the body with an interference fit and fixed with a 4-sided core.
The propellant charge (code 4A-33) has:
- a sleeve with an external thread, which is the combustion chamber of the charge;
- a charge of pyroxylin porous powder brand P-200 weighing 0.71 g;
- KVM-3 igniter primer.
The sleeve has a primer socket and 10 holes located around it, closed from the inside with an aluminum foil lid for tightness. VMG-K (P) fuse - head, instantaneous impact, with three safety stages (inertial, centrifugal, long-range arming 10-40 m) and self-destruction time - 14-19 s, designed to explode a grenade when it encounters an obstacle or self-destruct . The fuse has an aluminum body with a bushing and a nut with a liner, which contains:
- ignition mechanism;
- long-range cocking mechanism;
- impact mechanism of instantaneous and inertial action;
- self-destruction mechanism;
- detonator cap A30-T.
The ignition mechanism ensures the launch of long-range cocking and self-destruction mechanisms. It is assembled in the side channel of the housing bushing and has: an igniter primer and a tip with a spring in the cap. The long-range cocking mechanism ensures the safety of the fuse during service use and after firing at a range of 10-40 m. It has:
- a damper with a spring and a detonator cap KD-N-10 (for VMG-P - an igniter primer) in the transverse groove of the housing sleeve;
- a damper stopper located in the side vertical channel of the bushing, with a spring and a cap into which the PK-5 powder composition is pressed;
- a pin (radial stopper of the damper) with a spring in the cap.
The impact mechanism is designed to transmit the reaction force of the obstacle and trigger the fire chain. The mechanism is assembled in a nut and has:
- a cover on which a cap with a conical spring is attached to the bottom with a screw;
- spring split ring;
- housing liner with a sting and a spring in the central channel;
- two radial narrow plates located horizontally between the cap and the tip.
The self-destruct mechanism is designed to explode a grenade if for some reason the impact mechanism does not work. He has:
- powder composition MMS-2 in the semi-circular groove of the bottom of the housing bushing;
- beam detonator B-37 in the side vertical channel of the housing bushing with a VN transfer powder composition.
In total, the VMG-K fuse has six springs, one pin-type detonator cap and two beam ones, and one igniter cap.
The VMG-P fuse is designed similarly to the VMG-K fuse, but is placed in a metal cup and instead of the A30-T detonator capsule, which is moved to the bottom of the cup, it has a tray with an expelling powder charge (1.2 g). The A30-T detonator capsule is supplemented with a powder moderator. The VMG-P canister is connected to the grenade body without a fairing, which is the external difference between the VOG-25P round and the VOG-25 round.
Effect of a VOG-25 (P) shot
When the striker strikes the igniter primer of the propellant charge, a beam of fire ignites the powder charge. The powder gases formed as a result of the combustion of the charge in the cartridge case (first chamber), breaking through the foil, exit into the breech chamber of the barrel (second chamber) and eject the grenade at a speed of 76 m/s. Such a propellant charge device is called a two-chamber ballistic engine (“flying case”). When it encounters an obstacle, the fuse is triggered, causing a grenade explosion with a radius of continuous destruction by fragments of up to 6 m.
Action of the VMG-K fuse
In service circulation, the spring ring is located under a cover, which is pressed against the nut by the action of a conical spring. The flap is moved to the side and held in place by a stopper and a pin. When fired, from a sharp push, the cap, compressing the conical spring, settles with a spring ring, which, expanding, takes up space between the cap and the cap. After the action of the inertial forces ceases, the conical spring, straightening, lifts the cover, due to which a gap is formed between the cover and the nut - the inertial fuse is turned off (removed - 1st stage). At the same time, under the influence of inertial forces, the primer of the ignition mechanism, settling, is impaled on the sting. The fire beam ignites the powder composition in the semi-circular groove and the powder composition of the valve stopper on the other side. When a rotating grenade leaves the barrel, the radial pin moves under the influence of centrifugal force and releases the shutter, turning off the centrifugal fuse (2nd stage removed). In flight, at a distance of 10-40 m, the combustion of the long-range cocking powder composition ends and the stopper releases the damper, which, under the action of its spring, moves and installs the detonator capsule under the sting (the 3rd stage is removed) - the fuse is ready to explode.
When hitting an obstacle, the cap, through the spring ring, the ribs of the cap and the plate, transmits force to the sting, which pierces the detonator cap of the damper, causing the LZO-T detonator cap and the main explosive charge to fire. If the cover does not move when it encounters an obstacle, then the inertial movement of the nut liner towards the cover causes a similar sequence of activation of the fire chain. If for some reason the impact mechanism does not work, then after 14-19 seconds the powder composition of the self-liquidator finishes burning and the beam of fire through the transmission composition causes an explosion of the detonator capsule.
Action of the VMG-P fuse
Unlike the VMG-K, when it hits an obstacle, the sting pierces the igniter cap, which triggers the expelling charge, throwing the grenade to a height of 0.5-1.5 m, after which a beam of fire from the powder moderator causes an explosion of the A30-T detonator cap and the main explosive charge.
Characteristics of 40-mm active rounds VOG-25
Caliber 40 mm
Weapon type GP-25, GP-30, GP-34, RG-6
Initial grenade speed 76 m/s
Grenade weight 250 g
BB weight 48 g
Charge length 103 mm
Grenade self-destruction time is at least 14 s