My hybrid plans

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
Potato Demon
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Sat Jan 12, 2019 7:24 pm

Hi, I’m thinking of building a handheld burst disk hybrid which operates with a 4x mix of propane and air. Here are the specs: schedule 40 steel pipe construction, 3” x 16” chamber, golf ball size x 40” barrel, spark plug and modified arc lighter ignition (or nichrome wire, a 9 volt, and a toggle switch). Can I fire this without a stand without falling over? Or do I need to make a stand for it? I’m considering a muzzle brake because it might actually help because of the amount of gasses from a hybrid (I think so anyway). I’m not a very large person (I’m 13) so the recoil might be a little much for me.
Last edited by Potato Demon on Thu Mar 28, 2019 12:05 pm, edited 1 time in total.
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jackssmirkingrevenge
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Wed Jan 16, 2019 8:59 am

Plugging your specifications into HGDT gives us the following:

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1785 ft lbs (I assumed a 1 lb projectile) of muzzle energy is less than what you would expect for a typical 12 gauge shotgun load.

Here's a 13 year old kid shooting a much, much more powerful 10 gauge shotgun:

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If it's well supported and you lean into it properly, it shouldn't knock you over.
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Wed Jan 16, 2019 1:04 pm

Ok, thanks. I guess it wouldn’t kick much more that the dumpster cannon (a bad idea!).
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Fri Mar 15, 2019 8:54 pm

And if my metering pipe was made out of 1/2” schedule 40 steel, how long would it need to be?
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Sat Mar 16, 2019 5:13 am

hectmarr wrote:You have to make many weapons, because this field is long and short life
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Anatine Duo
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Sat Mar 16, 2019 12:06 pm

regarding recoil, I use http://www.shooterscalculator.com/recoil-calculator.php

Muzzle energy is related to recoil energy BUT things like propellant mass and momentum are significant. I plugged in the numbers for the 7000 grain projectile at 339fps in a 10 lb launcher and the recoil was considerable with zero propellant.
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Sat Mar 16, 2019 1:52 pm

Ok, thanks.
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Sun Mar 17, 2019 6:16 am

Anatine Duo wrote:the recoil was considerable with zero propellant.
That's why recoilless guns work ;)

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hectmarr wrote:You have to make many weapons, because this field is long and short life
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