SpudFiles

there reason a compound bow probably couldn't penetrate there wood as much as ur pneumatic could is because the arrow ur using in ur guns is like 2-3mm thick where as a compound arrow is say 8-10mm thick also wat poundage was your bothers compound bow set at..?

Massive update:
I DIESELED IT!!

Muhahahaaa

okay..here's the story.
Back in the day ( 1980's) my brother used pure ether to diesel a CO2 crosmann pistol.Fact.

Starter fluid mainly consists of ether.I recently bought a can...
If even a CO2 pistol can do it..I figured a pneumatic with enough dead space to compress would too.

So I started to work:
I removed the back..ornament-like fitting so I could access the rear of the barrel.I replaced the spring in a female QD so I could easily open it by inserting a ( cut to size) tip of a caulk tube.
I placed it there.

This way I could inject the starter fluid directly behind the rubber sabot.
Apon retracting the caulk-tip, the QD closes.

After pressurising the gun to a mere 25 bar ( I've shot it at 40!) I reset the sabot to the rear of the barrel and injected the fluid.

aimed...shot ( or better yet..fired!) BOOOOOM

The silent system removed itself from the muzzle...Quite violently I might add..
Before..40 bar could not do it..neither could repeatitive shots..all were silent before..
This shot felt much more violent than a " normal" shot too.

Beat you all to it...muhahaha.
Scary stuff..
Wait till psy tries this in his cannon...SOS for sure!!

Oh and I know someone wants to say..are you sure the muzzleblock was not just weakly fitted..
No it was not, It was threaded into the aluminium barrel.I could not turn it with the wrench anymore.
And the shot felt so violent it had to have been the diesel effect.No doubt.

I hope to put it up against Psy's chrony soon...if he'll let me.

Surely you've documented it somehow?

Of course not...I just rechecked the treads in the barrel and..the seemed shallower than I remembered...

I sure hope I'm not wrong and the thing just blew off by pneumatic force alone...

I'll have to try it again...but earlier..so the kids will still be up...

Interesting... Me like!!

Is there any science to calculatin how much fuel you should put in per volume of air? Or does it not matter as much

It doesn't matter..much

could you test it but with a regular spudgun loaded with a projectile ?? I mean.. ...just add some ether between the projectile and the valve

Haha that's awesome though. I wan to try this on one of my pneumatics now

could you test it but with a regular spudgun loaded with a projectile ?? I mean.. ...just add some ether between the projectile and the valve

Sure..I'll pressurise my steel 2" Mr.Porter pistonvalved cannon to 25 bar and diesel it..

NOT!

I'm sure I'd get away with it if it actually works too.
When I fire it at 14 bar the entire town can hear me.

alright i somewhat now what diesling is but not all of it can some one explain further.

Look it up. The fuel ignited due to the heat of compression when the cannon is fired... Very similar to a diesel engine....

In a nutshell

oh so it basicly works like diseling a spring air rifle it basicly makes a hybrid affect

I made my own variation of this design using a coaxial

[youtube][/youtube]

In the first shot in real time, you can hear the air leaking out past the captive sabot (or cabbot as we're now calling it ) after the shot. There's noise from the pilot exhaust and the impact but it's much, much quieter than when it's shot as a conventional launcher.

The "arrow" is a 6.5mm OD brass tube with a mild steel head, total weight is 22 grams. The perforations at the end are incidental because the tube is a recycled barrel from another project, but what they do is allow air to escape at the end of the piston's travel, reducing the air bumper effect. In spite of this, the delrin cabbot is undamaged many shots later, probably due to the relatively low velocity from the heavy projectile.

I'm waiting a silenced version of Helsing from you now Jack
Did you put the background music to show the effects? Well thought and as I can hear clearly the leak after the shot I'd say it worked very well.

wyz2285 wrote:I'm waiting a silenced version of Helsing from you now Jack

Hehe not sure if I want to make a pneumatic repeater or a single shot hybrid in this style:

Did you put the background music to show the effects? Well thought and as I can hear clearly the leak after the shot I'd say it worked very well.

The music is just what I happened to have on in the background at the time.

It's hard to isolate the noises, there is the pilot noise, projectile impact, cabbot impact... but the amount of noise this thing makes when fired in a conventional way is enough to make your ears ring, this is definitely silent by comparison.

Edit: another video, chronied it this time. At 250 psi, it's humming downrange at a mere 87.5 feet per second. That's only 5.8 ft lbs, so anaemic that it would be legal as an air pistol in the UK! boooooooooo!!!

[youtube][/youtube]

I think hybrid is the way to go...