PzGr40
28.11.2011, 01:08
Cutaway model of a 40 mm VOG-25 High explosive grenade for the underslung GP-25 and GP 30 rifle grenade launchers which are used under the Russian AK series assault rifles. The GP-25 was designed between 1975/1978, and was first put into use in the Afghanistan war. It was designed to be used with both the 7,62 AKM assault rifles and the newer 5,45 AK-74 assault rifles. It can be seen as the Russian awnser to the American 40 mm M-203 “underslung” barrel, which was widely used under the M16 rifle in the Vietnam war, adding imortant firepower to the troops.
The GP-25 as well as the M203 use the High-Low pressure system, be in in a different way. The VOG-25 grenades are inserted from forward in the short barrel, placing the reduced diameter powder chamber under the projectile body in a chamber in the back of the barrel. Upon firing , the powder in the powder chamber ignites and build up pressure, until the allready expanding gasses push the grenade forward into the wider part of the barrel. Here the gasses expand to full volume, propelling the grenade out of the barrel with 76,5 mtrs/sec.
The American M-203 used the High-Low pressure principle too, but the high pressure chamber was placed in the shellcase that had to be removed after each shot.
VOG-25 data:
Diameter : 40 mm
Lenth of projectile : 102 mm
Weight of grenade : 250 grams
Weight of the explosive charge : 48 grams A-IX-1 packed in a thin cartboard container.
Vo : 76,5 mtrs/sec
Range : 400 mtr
Lethal radius : 6 mtrs.
Exept for this VOG-25 High explosive grenade, there is also the VOG-25P. It has the same body as the VOG-25, but it has a fuze that propels the grenade upward appr. 1,5 mtrs. upon impact before exploding mid air. In 2001, the "Pribor" company has designed a HEAT grenade, able of penetrating up to 60/70mm steel plate. An Illumination round, as well as a Practice round are also available. The last available type is a teargas grenade called “Gvozd”.
The weapon and ammunition are used by the following countries : Georgia, Lithuania, North Korea, Russia, Ukraine
Functioning of the VMG-M -pyrotechnic delay- self destruct fuze (also see http://www.wk2ammo.com/showthread.php?t=6001: ) :
Upon firing, the sleeve (1) is moved downward by the inertia force, riding the spring (2). This creates the space needed for the rolled up spring (3) to expand into a groove (4)and prevent this from being closed as the sleeve (1) moves upward again, together with the hammer pin (5). The two axial revolving T-shaped levers (6) are also released and rotate upward with their centre piece, enabeling the firing pin (7) to move upward under influence of it’s spring (8).
The centrifugal safety pin (9) is retracted from the firing cap slider, riding it’s spring (10), releasing the firing cap slider (11).
At the same moment the firing cap (12) of de self detruct mechanism rides the spring (13) down into the firing pin (14). This ignites a powder train (15) that runs into two directions. One direction is the short delay that burns away a small sulfer pellet in the spring loaded vertical pin (16) that prevents the firing cap slider (11) from sliding under the firing pin. When the pellet is burned away, the spring retracts the pin and the v-shaped spring (17) on the firing cap slider pulls the firing cap slider under the firing pin, arming the projectile. The other direction is the pyrotechnic fuze which burns through a circular channel in the base of the safety block to the other side and ignites a big –heat senisitive- detonator (19,Blue) which is connected to the firing cap with a channel. This is the self destruct mechanism. It will function in between 28 and 36 seconds.
Upon impact, the sleeve (1) is hammered down by the hammer pin (5), fastly rotating both levers (6), and pushing the firing pin (7) in the firing cap (18). The flame of the firing cap will pass into the detonator (pink) through the central channel, exploding the main charge (gray) in the projectile body.
The VOG-25 in use:
http://www.youtube.com/watch?v=BqqsYICJUVw
Regards, DJH
The GP-25 as well as the M203 use the High-Low pressure system, be in in a different way. The VOG-25 grenades are inserted from forward in the short barrel, placing the reduced diameter powder chamber under the projectile body in a chamber in the back of the barrel. Upon firing , the powder in the powder chamber ignites and build up pressure, until the allready expanding gasses push the grenade forward into the wider part of the barrel. Here the gasses expand to full volume, propelling the grenade out of the barrel with 76,5 mtrs/sec.
The American M-203 used the High-Low pressure principle too, but the high pressure chamber was placed in the shellcase that had to be removed after each shot.
VOG-25 data:
Diameter : 40 mm
Lenth of projectile : 102 mm
Weight of grenade : 250 grams
Weight of the explosive charge : 48 grams A-IX-1 packed in a thin cartboard container.
Vo : 76,5 mtrs/sec
Range : 400 mtr
Lethal radius : 6 mtrs.
Exept for this VOG-25 High explosive grenade, there is also the VOG-25P. It has the same body as the VOG-25, but it has a fuze that propels the grenade upward appr. 1,5 mtrs. upon impact before exploding mid air. In 2001, the "Pribor" company has designed a HEAT grenade, able of penetrating up to 60/70mm steel plate. An Illumination round, as well as a Practice round are also available. The last available type is a teargas grenade called “Gvozd”.
The weapon and ammunition are used by the following countries : Georgia, Lithuania, North Korea, Russia, Ukraine
Functioning of the VMG-M -pyrotechnic delay- self destruct fuze (also see http://www.wk2ammo.com/showthread.php?t=6001: ) :
Upon firing, the sleeve (1) is moved downward by the inertia force, riding the spring (2). This creates the space needed for the rolled up spring (3) to expand into a groove (4)and prevent this from being closed as the sleeve (1) moves upward again, together with the hammer pin (5). The two axial revolving T-shaped levers (6) are also released and rotate upward with their centre piece, enabeling the firing pin (7) to move upward under influence of it’s spring (8).
The centrifugal safety pin (9) is retracted from the firing cap slider, riding it’s spring (10), releasing the firing cap slider (11).
At the same moment the firing cap (12) of de self detruct mechanism rides the spring (13) down into the firing pin (14). This ignites a powder train (15) that runs into two directions. One direction is the short delay that burns away a small sulfer pellet in the spring loaded vertical pin (16) that prevents the firing cap slider (11) from sliding under the firing pin. When the pellet is burned away, the spring retracts the pin and the v-shaped spring (17) on the firing cap slider pulls the firing cap slider under the firing pin, arming the projectile. The other direction is the pyrotechnic fuze which burns through a circular channel in the base of the safety block to the other side and ignites a big –heat senisitive- detonator (19,Blue) which is connected to the firing cap with a channel. This is the self destruct mechanism. It will function in between 28 and 36 seconds.
Upon impact, the sleeve (1) is hammered down by the hammer pin (5), fastly rotating both levers (6), and pushing the firing pin (7) in the firing cap (18). The flame of the firing cap will pass into the detonator (pink) through the central channel, exploding the main charge (gray) in the projectile body.
The VOG-25 in use:
http://www.youtube.com/watch?v=BqqsYICJUVw
Regards, DJH