fl(air) gun - mechanically locked pneumatic cartridge for a 26.5mm flare gun

Show us your pneumatic spud gun! Discuss pneumatic (compressed gas) powered potato guns and related accessories. Valve types, actuation, pipe, materials, fittings, compressors, safety, gas choices, and more.
hectmarr
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Mon Oct 21, 2024 5:17 am

jackssmirkingrevenge wrote:
Sun Oct 20, 2024 10:47 am
Shame it's so quite in here. Ah well, the tinkering continues and holes are still being blasted though innocent cans :D

Here is a second version of the flare gun cartridge with a steel chamber and aluminum piston. Fitted with a 6 inch long 0.75 cal barrel it's pushing empty 12 gram CO2 capsules at just under 300 feet per second. That's not too dramatic but at about 510 grains that works out at 100 ft lbs of muzzle energy!

Good job!!
I missed seeing holes, alone in this space-time, but definitely powerful.
It's like the poet said: "There may not be poets, but there will ALWAYS be poetry" :)
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jackssmirkingrevenge
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Tue Oct 22, 2024 9:41 am

hectmarr wrote:
Mon Oct 21, 2024 5:17 am
"There may not be poets, but there will ALWAYS be poetry" :)
Well said :D

Here is what the new design looks like internally, roughly to scale:

Image

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.
hectmarr wrote:You have to make many weapons, because this field is long and short life
hectmarr
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Tue Oct 22, 2024 2:57 pm

jackssmirkingrevenge wrote:
Tue Oct 22, 2024 9:41 am
hectmarr wrote:
Mon Oct 21, 2024 5:17 am
"There may not be poets, but there will ALWAYS be poetry" :)
Well said :D

Here is what the new design looks like internally, roughly to scale:

Image

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.
Wow, a remarkably optimized system, good thing. It's great that you were able to thoroughly test this cartridge, and logically, the improvements seen in your drawing will make it last longer. Good job!!
hectmarr
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Tue Oct 22, 2024 3:06 pm

The air filling system you designed is the best... I would say the perfect check valve!! :)
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