Cutaway model of an Oerlikon 30x172 304RK aircraft revolver cannon cartridge, later renamed the KCA.
The projectile is made of a hardened steel nose -housing the fuze, screwed to a mild steel High explosive back piece. A wind shield is placed over the hardened nose. An aluminium filler piece is placed between the nose and the windshield. On impact this will generate a bright flash.
The fuze is really interesting;
Upon firing, the cap (3) housing a brass "crush-bellow" moves down -crushing the brass bellow-, overriding the spring (7). It enables the firing pin housing (4) which houses the firing pin(8 ) and it's spring (7) to move forward a little, releasing the ball housing the firing cap (10) and enabeling it to set itself in line with the firing cap. The four balls (5) in the firing pin housing fall into the groove in top of the brass ring (6) which keep the firing pin housing suspended as long as the force of the four balls in the groove (centrifugal force) is greater than the force of the spring (7). If no target is hit , the speed and rotation will decreaseup to a point where the spring forces the balls back into the firing pin housing , driving the firing pin into the firing cap, exploding the detonator (11)
If a target is hit, the desceleration will throw the firing pin housing (4) forward untill the armour is pierced and the desceleration stops. After piercing the armour -when the speed is constant-, the firing pin spring (7) will push the firing pin into the firing cap, exploding the firing cap and the detonator. The projectile will detonate after passing the armour.
The shellcase is zinc clad steel. The primer is electrically fired.
Remaining base stamp : 2 D Oe 54
No further info is known about this projectile, so if anyone has info (factory descriptions preferably), please let me know.
Thanks in advance,
Regards DJH
The projectile is made of a hardened steel nose -housing the fuze, screwed to a mild steel High explosive back piece. A wind shield is placed over the hardened nose. An aluminium filler piece is placed between the nose and the windshield. On impact this will generate a bright flash.
The fuze is really interesting;
Upon firing, the cap (3) housing a brass "crush-bellow" moves down -crushing the brass bellow-, overriding the spring (7). It enables the firing pin housing (4) which houses the firing pin(8 ) and it's spring (7) to move forward a little, releasing the ball housing the firing cap (10) and enabeling it to set itself in line with the firing cap. The four balls (5) in the firing pin housing fall into the groove in top of the brass ring (6) which keep the firing pin housing suspended as long as the force of the four balls in the groove (centrifugal force) is greater than the force of the spring (7). If no target is hit , the speed and rotation will decreaseup to a point where the spring forces the balls back into the firing pin housing , driving the firing pin into the firing cap, exploding the detonator (11)
If a target is hit, the desceleration will throw the firing pin housing (4) forward untill the armour is pierced and the desceleration stops. After piercing the armour -when the speed is constant-, the firing pin spring (7) will push the firing pin into the firing cap, exploding the firing cap and the detonator. The projectile will detonate after passing the armour.
The shellcase is zinc clad steel. The primer is electrically fired.
Remaining base stamp : 2 D Oe 54
No further info is known about this projectile, so if anyone has info (factory descriptions preferably), please let me know.
Thanks in advance,
Regards DJH
