Breech System For historical Pak 36

Harness the power of precision mixtures of pressurized flammable vapor. Safety first! These are advanced potato guns - not for the beginner.
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Alexypak36
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Tue Feb 09, 2021 12:27 pm

So tels me what is the rôle of rifling in the brenneke rounds ? It is for stability or something ?

So its complicated to give a spin on a rounds ? I have no idea ^^

By night with tracer round i love it. I have an idea paint the round with phosphorescent paint. Maybe at night it works. Go for lot of test in the garden ^^lmao
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jackssmirkingrevenge
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Tue Feb 09, 2021 1:03 pm

Alexypak36 wrote:
Tue Feb 09, 2021 12:27 pm
So tels me what is the rôle of rifling in the brenneke rounds ? It is for stability or something ?
In the past most shotguns had fixed chokes at the end of the barrel. Trying to fire a full diameter slug through a choked barrel means it will probably get stuck in the muzzle and blow the barrel.

The "ribs" on the Brenneke type slugs allow the lead to be deformed as it goes through the choke allowing the projectile to pass through without creating a dangerous spike in pressure.
So its complicated to give a spin on a rounds ? I have no idea ^^
In a smoothbore barrel, yes...

Maybe make an APFSDS dart like the Germans were experimenting with in 37mm?

Image

:D

But seriously, I would go for a cup shaped foster type slug... unless you want the challenge of making your own rifled barrels.
By night with tracer round i love it. I have an idea paint the round with phosphorescent paint. Maybe at night it works. Go for lot of test in the garden ^^lmao
It works for airsoft, why not...
hectmarr wrote:You have to make many weapons, because this field is long and short life
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Alexypak36
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Tue Feb 09, 2021 1:14 pm

i think a warehead shell is the best form more than spheric one ..

the weak power of the weapon and its range comapre to the real one I do not think necessary to use grooves. In addition, the machining of these guns is hell for an individual

I have some projectile design for my pak36 like:


I think I have more stability with a warhead rather than a sphere. after I could be wrong, I did not do any tests :D
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Alexypak36
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Tue Feb 09, 2021 3:12 pm

I have the results of my calculs for the power. However I ask a question, in the simulator, I put a tensile strength of 10 bar on theburst disc. How to obtain these 10 bar of resistance by adding layers of aluminum foil and by doing tests or can we determine the thickness by calculs ? :D


these results seem good to me with the characteristics of my combustion chamber etc... and using your method with the syringe ;)
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jackssmirkingrevenge
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Wed Feb 10, 2021 2:11 pm

Alexypak36 wrote:
Tue Feb 09, 2021 3:12 pm
However I ask a question, in the simulator, I put a tensile strength of 10 bar on theburst disc. How to obtain these 10 bar of resistance by adding layers of aluminum foil and by doing tests or can we determine the thickness by calculs ? :D


Normally we do trial and error. Sometimes tightening the cap to a different torque will change the burst pressure.
these results seem good to me with the characteristics of my combustion chamber etc... and using your method with the syringe ;)
What is the volume of your chamber?
hectmarr wrote:You have to make many weapons, because this field is long and short life
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hectmarr
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Wed Feb 10, 2021 2:44 pm

To know the approximate necessary force at which its rupture disc breaks, you must assemble the disc inside the system and with a rod of the same diameter as the area exposed to the explosion pressure, gradually tighten and measure the force with a balance. So you can determine at what force it breaks. You already know the collapse force, the area of your rupture disc exposed to high pressure gases, and you can deduce the necessary pressure.
It is important that the rod you use fits snugly into the channel that communicates the combustion chamber with the rupture disc.
First the fact and then the law.
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Alexypak36
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Wed Feb 10, 2021 2:58 pm

jackssmirkingrevenge wrote:
Wed Feb 10, 2021 2:11 pm

What is the volume of your chamber?
I have 1216,5ml for my combustion chamber
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Alexypak36
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Wed Feb 10, 2021 3:01 pm

hectmarr wrote:
Wed Feb 10, 2021 2:44 pm
To know the approximate necessary force at which its rupture disc breaks, you must assemble the disc inside the system and with a rod of the same diameter as the area exposed to the explosion pressure, gradually tighten and measure the force with a balance. So you can determine at what force it breaks. You already know the collapse force, the area of your rupture disc exposed to high pressure gases, and you can deduce the necessary pressure.
It is important that the rod you use fits snugly into the channel that communicates the combustion chamber with the rupture disc.

Not stupid, I will try this principle during my tests. Anyway, I would porgressivment increase the thickness of the burst disc with aluminum foil to make it work well.
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Alexypak36
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Wed Feb 10, 2021 4:28 pm

what is the thickness of a burst disc in general?

I did some tests on solidworks but I find them bad ... :roll:
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Wed Feb 10, 2021 11:32 pm

Looks like you will have to use more than 1x mixture, otherwise your chamber to barrel ratio will be too small. Do you know what your designs' chamber and barrels volumes are?
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Alexypak36
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Thu Feb 11, 2021 2:01 am

It's a shperic form, go see the diagram in the first step of on shell. ^^ Yes I will need a mixture of at least 2 or 3 to start.
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Anatine Duo
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Fri Feb 12, 2021 7:34 am

edited 1234
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