SYDNEY AUSTRALIA 2227 (ABN 96 078 508 264) Ph:+61 2 9016 4695
"Helping others to have a future assures our own."
Small Arms Silencer Project
1972 Silencer for suppression of noise emanating from the muzzles of weapons firing rounds travelling at supersonic speeds. Silencer only protruded 50 mm past muzzle of weapon in contrast to the US Sionics Silencer which protruded 300mm and required a special gauge, plug bore lower limit, when being fitted. Misalignment was common, potentially resulting in breech explosion when a round hit a baffle in the silencer. The prototype silencer overcame these problems but had a comparable sound attenuation performance.
The key to the effectiveness of this silencer design was a "gas diode". The diode worked by diverting gas just behind the bullet off into side passages. As the bullet entered an "open space", that gas which was not tapped off behind the round would start to lag behind, the gas in the side passages was then directed back onto the main flow, thereby causing local congestion which encouraged the gas to erupt out through large side passages. This gas would then expand into a large container running back along the weapon's barrel. As the gas expanded, the pressure wave would rapidly diminish which then meant the sound wave created was around 90dB less (from a 180dB peak) by the time it escaped into the outer atmosphere. This represented a significant reduction in the sound of the weapon.