SpudFiles

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

Alexypak36 wrote: Tue Feb 09, 2021 12:27 pmSo 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?





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...

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

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 ?


these results seem good to me with the characteristics of my combustion chamber etc... and using your method with the syringe

Alexypak36 wrote: Tue Feb 09, 2021 3:12 pmHowever 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 ?

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?

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.

jackssmirkingrevenge wrote: Wed Feb 10, 2021 2:11 pm
What is the volume of your chamber?

I have 1216,5ml for my combustion chamber

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.

what is the thickness of a burst disc in general?

I did some tests on solidworks but I find them bad ...

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?

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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