SpudFiles

Joerg's new toy.

I fooled around with this cartridge design decades ago but gave up because it was long before 4500 psi handpumps were available. This sparked interest in it again, maybe with a 40mm size cartridge ... maybe rimless for better feeding in JSR's brain.

any clue on how the cartridges on the defensive pistol work?

Thank you for sharing this video - I didn't know that these cartridges existed. Surprisingly, I was unable to find an internal diagram, so I ordered a couple of them and will post photos of the internals when they arrive.

Interesting stuff! It seems to go around laws restricting barreled weapons by effectively being a spigot gun without a "barrel" per se.

I've found a picture of the cartridge internals:



My impression is that it is the exhaust valve piston design we all know and love, with the pilot valve being a burst disk.

I'm guessing it's because of the difficult of actuating a resettable pilot valve at such high pressures.

Interesting stuff but we all don't love exhaust valve piston designs. Relying on the launcher never to leak to prevent a misfire is not ideal.

That's true, although for most of the setups we see on spudfiles a slow leak would not be sufficient to pilot the valve, as it's rare that the the piston or diaphragm is a perfect seal, especially without the shock of a sudden pressure imbalance.

True, but I quit using them after a misfire from merely degassing the launcher as apparently the pressure behind the diaphram leaked out faster than the ballast side and there was enough pressure left to lob a round into the neighbor's yard. Luckily no one was hurt and no damage to any property but it could have been a lot worse.

I dont understand how the main valve works (i believe it is the white thing with the spring), it must be something like a 2 way QEV with the burst disk acting like a pilot valve, but how does the valve open after the burst disk is pierced?

Take a look at this thread, plenty of examples on the same concept.