Balcony Shoot #7 - KN/Silver Gerb

Date: 2003-09-20


Test of a wheel driver composition I saw on I didn't have all the Aluminium grades required, so I had to use a mixture of -325 mesh spherical and 100 mesh flitters.

Tube of paper 8 mm ID, not pasted, this was just a quick test. Cat litter nozzle and end plug. First increment rammed was straight meal as a prime, then the KNO3/Al/S mixture.

Fused with my standard meal/NC twisted tissue paper fuse.


Weird hold-fire, then an explosion.

The prime ignited and burnt for a short while, then all traces of combustion ceased. No light, very little smoke, nothing. I waited, and in about 5 seconds there was a spectacular bang and flash, followed by some bright combustion of the remains of the KN/Silver composition.

The nozzle and case were still intact after the prime burnt out, but the explosion blew out the nozzle and shredded the top of case. The remaining half of the KN/Silver charge burt with a rather pinkish light, while the explosion flash itself was very blue-white.

Unfortuately the explosion was not caught on video, the recording was stopped after the prime burn out. It definately looked like it had failed. The recording was restarted and captured the end of the remaining composition burning out.

There wasn't much left to autopsy, the case was completely consumed, the nozzle was found, coated completely with a smooth grey/black material, I found this odd in itself.

I want to test this composition again, the hold-fire is interesting, and potentionally very dangerous so I want it resolved. I am not sure if the explosion was just a structural failure, but my gut instinct says it wasn't and something rather strange and energetic happened in the KN/Silver composition.


title type size
Ignition & Primer Burn video/x-msvideo 1.114 Mbytes
Remains Burnout video/x-msvideo 3.493 Mbytes