fl(air) gun - big bore air pistol conversion

[jackssmirkingrevenge]

I've made a more refined variation of this with a steel chamber and aluminum piston, with a 6 inch long 0.75 cal barrel it's pushing empty 12 gram CO2 capsules at just under 300 feet per second, at about 510 grains that works out at 100 ft lbs of muzzle energy

[sb327]

Excellent work!!!

Dave

[Rob M]

thats awesome!!!!!!!!!!!!!!

[JuryRigger]

W-O-O-F-!....
Too cool!
Excellent work!
Jesse

[jackssmirkingrevenge]

Thanks gents

Here is what the new design looks like internally more or less to scale:



The piston locking balls are now kept in place with a central ball, with the latter's centerline slightly biased to the rear in order to prevent it from simply being pushed out under pressure.  This should greatly reduce wear and provides a more positive disengagement compared to the pin, and indeed unlike the previous version it is practically self-resetting after every shot.

The aluminum piston is less than half the weight of the previous steel model but I have added a steel ring in the contact area with the balls.  I've also moved the endcap o-rings to the inner edge, that way the threads aren't under pressure which should make it safer.

[Rob M]

cool.. so its filled from the front , and the fill pressure displaces an oring ?

[jackssmirkingrevenge]

so its filled from the front , and the fill pressure displaces an oring ?

Yes exactly, it's the second o-ring from the left on the piston.  One thing I learned is that you do not want that o-ring in contact with the port because the rubber will get sucked it!  It should seal all around in a groove that is slightly undersized.

[JPSAXNC]

I wonder if you could just build a big revolver that shot full co2 carts, with a pin on the hammer to puncher them?

[jackssmirkingrevenge]

I wonder if you could just build a big revolver that shot full co2 carts, with a pin on the hammer to puncher them?

I actually tried this and the results were... interesting:



The issue of course is that while the pressure is there, a small hole has terrible flow and will not give good performance, essentially it turns the CO2 cartridge into a rocket.

The way I see it actually working with some decent power behind it would be something like this:



The cartridge would be held by friction by a tight o-ring, this would give time for pressure to build up behind it until it pops out like a champagne cork.

[JPSAXNC]

Yes, That looks good. Some time back someone was selling air canes that fired a CO2 cart, with a long barrel it could probably develop a good velocity.

[jackssmirkingrevenge]

Reuploaded video links as due to overzealous moderation of historical footage, my YouTube channel has been terminated and the content is no longer accessible:

[JPSAXNC]

Holy xxxx!  That is awesome.

[JPSAXNC]

That shot through the square tin box was Samurai level.

[jackssmirkingrevenge]

That shot through the square tin box was Samurai level.

When it has sufficient mass even a relatively slow-moving projectile can be impressive