pzgr40
Well-Known Member
Cutaway model of a Russian BK-5M 100x695 HEAT-T cartridge as used in the 100mm D-10 tank gun for the T54/55.
The projectile is build up of a mild steel body in which a red copper cone is placed. On top of the cone a steel deflector is screwed into the body. The nosepiece is screwed over the deflector. The steel deflector protects the cone from damage when the detonator of the nose fuze detonates, but allows the flame straight downward.
An electrically activated aluminium nose fuze is screwed in top of the projectile. When activated, the fuze shoots a flame down into the cone, igniting the detonator (red) in the wave shaper below the cone.
The wave shaper ignites the main charge downward, forcing the explosion to go around the wave shaper before climbing up along the cone. The detonation wave is now shaped in such a way that the force of the detonation will hit the copper cone nearly perpendicular, improving penetration.
The driving bands are placed on a loose ring, locked up by a nut, Upon firing , the ring will reduce the rotation of the projectile to 1/3 of the normal rotation, thereby reducing loss of penetration due to spalling. The less rotation a shaped charge projectile has, the better.
As the rotation of the projectile is reduced 2/3, the projectile may become unstable and less precise. To overcome this reduction in balance, a steel tailpiece is screwed to the base of the projectile, housing six knive shaped pop out fins. This tailpiece also houses the tracer element. After leaving the barrel the fins swing out, balancing the projectile in it’s flight.
The shellcase is made of galvanized steel. A percussion primer with a black powder magazine is placed in the base. The shellcase is filled with a bag containing a small bundle of sticks, further filled with granular powder. A cartboard closing disc keeps the powder charge in it’s lower position.
I do not know the type designation of the nose fuze (maybe X can help me out here) , but it functions as follows:
The fuze is build up of an aluminium outer housing (1), in which the aluminium inner housing (2 ) is placed, which houses the safety mechanisms.
Upon firing, the firing safety, formed by a pin (3) on a spring (4) moves backward, riding the spring. When the pin moves down , it releases a steel ball (5) that falls out of it’s hole, releasing a slider (6) to move outward, pushed by a “peg type” spring (7). The slider moves from short circuit to electrically ‘in line’.
In the nose of the fuze, a Piezo-electric element (8 ) is placed. Upon impact, this element starts delivering current when placed under pressure. This current ignites an electric squib detonator (9) , which detonates the booster (10) . The flame of this booster spits back in the lower detonator (red) in the wave shaper at the base of the cone, exploding the main charge.
Before loading the projectile into the barrel, the protective cap (11) is removed, releasing the thin wind cap over the fuze nose (12). However, Russian manuals state that that when firing during heavy rain the cap should not be removed as to prevent premature detonation of the projectile.
Vo: 900 mtr/sec
Penetration of the BK-5M HEAT projectile : 375mm steel at 90 degrees.
On picture 04, the BK-5M is pictured together with the BM-8 APDS-T. A description of this cartridge can be found here:
http://www.wk2ammo.com/showthread.p...DS-T-cartridge-for-100mm-D-10-Gun-of-the-T-55
Regards, DJH
The projectile is build up of a mild steel body in which a red copper cone is placed. On top of the cone a steel deflector is screwed into the body. The nosepiece is screwed over the deflector. The steel deflector protects the cone from damage when the detonator of the nose fuze detonates, but allows the flame straight downward.
An electrically activated aluminium nose fuze is screwed in top of the projectile. When activated, the fuze shoots a flame down into the cone, igniting the detonator (red) in the wave shaper below the cone.
The wave shaper ignites the main charge downward, forcing the explosion to go around the wave shaper before climbing up along the cone. The detonation wave is now shaped in such a way that the force of the detonation will hit the copper cone nearly perpendicular, improving penetration.
The driving bands are placed on a loose ring, locked up by a nut, Upon firing , the ring will reduce the rotation of the projectile to 1/3 of the normal rotation, thereby reducing loss of penetration due to spalling. The less rotation a shaped charge projectile has, the better.
As the rotation of the projectile is reduced 2/3, the projectile may become unstable and less precise. To overcome this reduction in balance, a steel tailpiece is screwed to the base of the projectile, housing six knive shaped pop out fins. This tailpiece also houses the tracer element. After leaving the barrel the fins swing out, balancing the projectile in it’s flight.
The shellcase is made of galvanized steel. A percussion primer with a black powder magazine is placed in the base. The shellcase is filled with a bag containing a small bundle of sticks, further filled with granular powder. A cartboard closing disc keeps the powder charge in it’s lower position.
I do not know the type designation of the nose fuze (maybe X can help me out here) , but it functions as follows:
The fuze is build up of an aluminium outer housing (1), in which the aluminium inner housing (2 ) is placed, which houses the safety mechanisms.
Upon firing, the firing safety, formed by a pin (3) on a spring (4) moves backward, riding the spring. When the pin moves down , it releases a steel ball (5) that falls out of it’s hole, releasing a slider (6) to move outward, pushed by a “peg type” spring (7). The slider moves from short circuit to electrically ‘in line’.
In the nose of the fuze, a Piezo-electric element (8 ) is placed. Upon impact, this element starts delivering current when placed under pressure. This current ignites an electric squib detonator (9) , which detonates the booster (10) . The flame of this booster spits back in the lower detonator (red) in the wave shaper at the base of the cone, exploding the main charge.
Before loading the projectile into the barrel, the protective cap (11) is removed, releasing the thin wind cap over the fuze nose (12). However, Russian manuals state that that when firing during heavy rain the cap should not be removed as to prevent premature detonation of the projectile.
Vo: 900 mtr/sec
Penetration of the BK-5M HEAT projectile : 375mm steel at 90 degrees.
On picture 04, the BK-5M is pictured together with the BM-8 APDS-T. A description of this cartridge can be found here:
http://www.wk2ammo.com/showthread.p...DS-T-cartridge-for-100mm-D-10-Gun-of-the-T-55
Regards, DJH
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