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ecos
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[*] posted on 10-6-2016 at 15:04


Quote: Originally posted by nitro-genes  
Brass balls are admirable, but as endcaps on a gun not so much...:) Most metal piping is welded btw and not seamless, can't tell for sure from the photo, but it looks like ordinary plumbing pipe which is probably welded. This thing wouldn't survive blackpowder, let alone a chlorate based propellant...Even if it would survive a couple of blackpowder shots, the material will fracture (as it wasn't meant for this) and may suddenly give in while you are holding it. Recipe for getting seriously hurt.

[Edited on 10-6-2016 by nitro-genes]

I just added a photo for a zip gun from internet. I was planning to use water pipes instead since they are thicker.
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ecos
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[*] posted on 10-6-2016 at 15:05


I found a lot of books on internet about how to make a gun : http://www.prexis.com/sten/Holmes_50.pdf
this book is for 50 cal gun.

I have no interest in following the schematics , I am behind the science of how it was designed and different aspects.

[Edited on 10-6-2016 by ecos]
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Tsjerk
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[*] posted on 10-6-2016 at 15:29


You really don't get it do you? You cannot use any welded tubing for the barrel. It is just not going to work.

Besides that, do you have any idea about the kind of steal (assuming you are going for steal) your water pipes are made of? And with kind I don't mean iron....

Long story short: any amount of black powder between two metal balls in a metal water pipe makes a nice pipe bomb. If this is not the case I'm sure you are not going to be satisfied with the monding speed and you are going to crank it up until you do have pipe bomb.

Edit: and yes, water pipes are welded

[Edited on 10-6-2016 by Tsjerk]
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nitro-genes
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[*] posted on 10-6-2016 at 15:35


Make sure you also read "How to build an Abrams tank from plumbing supplies" by Prof. Dr. Dick Head...
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ecos
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[*] posted on 10-6-2016 at 16:24


:) , the gun was made by many people on youtube.
if you are interested , I can share links.


@Tsjerk, Thx for the info.

[Edited on 11-6-2016 by ecos]
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morganbw
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[*] posted on 11-6-2016 at 12:11


Good God people. Let the man make his gun. Smart (maybe not ) but he will discover quickly enough if it works or not. For me I would simply buy one, but I am not he.
I do agree that black powder should be considered.
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aga
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[*] posted on 11-6-2016 at 14:35


https://www.youtube.com/watch?v=QM7kCcfdcsE



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ecos
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[*] posted on 11-6-2016 at 15:24


simple zip gun in action : https://youtu.be/KRSxf87WfLw
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doomeister
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[*] posted on 18-6-2016 at 01:18


If you are going to build a firearm, please use black powder. If you are hellbent on using smokeless, please don't use plumbing pipe. Try to look for some seamless steel barrels, 4140 or 4150 chrome moly, or if must be, some BSP piping.



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ecos
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[*] posted on 18-6-2016 at 15:34


Thx for the warning.
I have a question , the BP inside the bullet undergoes deflagration or detonation?

i think designing a gun is more complex than I thought : https://www.youtube.com/watch?v=1rPm-9ujt0Y
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Metacelsus
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[*] posted on 18-6-2016 at 16:46


Deflagration. Detonation would destroy the gun (and possibly maim the wielder).



As below, so above.
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careysub
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[*] posted on 18-6-2016 at 17:11


Quote: Originally posted by ecos  
Thx for the warning.
I have a question , the BP inside the bullet undergoes deflagration or detonation?


Deflagration. One reason that BP is strongly recommended as a propellant is that it cannot detonate.

Quote:

i think designing a gun is more complex than I thought : https://www.youtube.com/watch?v=1rPm-9ujt0Y


Yes it is. I suggested consulting a book on interior ballistics for a reason.
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ecos
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[*] posted on 19-6-2016 at 02:33


@careysub do you have a book to recommend?
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NedsHead
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[*] posted on 19-6-2016 at 05:01


My advice is to start out with straight wall black powder pistol calibres and stay away from bottleneck cartridges until you have some experience, I'm starting a project of my own soon, I'll let you know how it goes
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[*] posted on 20-6-2016 at 04:09


@Nedshead, looking forward for your result :) Good luck.

I forgot to mention my reference and video for the book which explains how to make a 50 cal gun.

picture-23-5.png - 497kB

book : www.prexis.com/sten/Holmes_50.pdf

step by step video : https://youtu.be/KQe8gVxxsyk

I must admit that i got surprised when I knew that BP deflagrate not detonate. I thought the bang sound is due to small explosion that gives kinetic energy to bullet to move fast.



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[*] posted on 20-6-2016 at 10:27


Deflagration can go over the 350 m/s (speed of sound in air) up to >2000 m/s



PH Z (PHILOU Zrealone)

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hissingnoise
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[*] posted on 20-6-2016 at 10:51


This thread has made me uneasy at its outset and I'm quite surprised and somewhat dismayed that Polverone has allowed this thread continue, especially in light of recent events, one of which featured a homemade gun used in committing a coldblooded murder!

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[*] posted on 20-6-2016 at 11:11


Quote: Originally posted by hissingnoise  
This thread has made me uneasy at its outset and I'm quite surprised and somewhat dismayed that Polverone has allowed this thread continue, especially in light of recent events, one of which featured a homemade gun used in committing a coldblooded murder!


Give a knife to a fanatic idiot and he will do a disaster...as bad if not worst as with a gun...

With the minimum chemical knowledge a fool can do a mass killing... (fire, gas explosion, chemical weapons)

A one shot gun is really the least problem...the problem is the shooter and his insane mind...

[Edited on 20-6-2016 by PHILOU Zrealone]




PH Z (PHILOU Zrealone)

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[*] posted on 20-6-2016 at 14:22


Quote: Originally posted by hissingnoise  
This thread has made me uneasy at its outset and I'm quite surprised and somewhat dismayed that Polverone has allowed this thread continue, especially in light of recent events, one of which featured a homemade gun used in committing a coldblooded murder!


Considering all of the attacks with explosives over the years they might as well close the entire energetics section, it's that type of attitude that gets common chemicals like acetone and H₂O₂ banned.
Blame the fool not the tool!

[Edited on 20-6-2016 by OneEyedPyro]
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nitro-genes
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[*] posted on 20-6-2016 at 16:29


In general I agree to the statements above regarding closing this discussion, due to the missing science, novelty, and mainly practical discussion about something that could be seen as a weapon. (Hey guys, look...I'm gonna build .50 canon from youtube) Then again, like said before, it's all about the person, in principal everything can be used as a weapon, though sciencemadness is not the place IMO to discuss these things. Like the E&W forum, it also tends to attract another type of crowd so to say. Besides, sciencemadness also isn't the best forum for this probably, as there are likely other more specific fora on the internet with more knowledgeable people regarding this subject, which would mainly involve machining skills and knowledge about specific alloys and their properties and much less about energetic materials.

Some things to keep in mind though:

Point 1: In many countries weapons are in fact legal, sometimes even without any special license. It's pretty small minded to think of one particular incident, involving a particular firearm, in one particular country, having a particular law regarding firearms, to consider not allowing any discussion regarding this matter.
Point 2: This board is called Sciencemadness for a reason, one could argue there isn't much science in propelling things from a barrel (there actually is, just not in this thread.) On the other hand sometimes it's a bit of a grey area, for example, a light-gas gun would be very similar, though discussion would likely be allowed due to science interest and non-weapon use. And lets not fool each other in thinking that experimenting with energetic materials is much more dangerous than other types of chemistry. I'd rather have someone experimenting with making a blackpowder rifle from scratch than one mass producing ketene for acetic anhydride or working with large amounts of ether as my neighbour. Many potentially misusable and dangerous chemicals and potential precursors are openly discussed here, same goes for bacterial strain isolation and growth media, which is a real potential threat taken very seriously nowadays and implemented as part of safety and regulation prescriptions in many biochemitry labs. We should also not discuss making of alkaline earth metals, these are very explosive when in contact with ordinary water!
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ecos
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[*] posted on 20-6-2016 at 17:01


I am not talking about mechanical designs , machinary tools , ...etc
I am talking about using EM for making a rifle. In the beginning of the thread I was talking about AP as gun powder.

The forum here discuss a lot about EM as explosives. this can make a disaster.

A gun or a bullet is less problem than this.


Quote: Originally posted by PHILOU Zrealone  
Deflagration can go over the 350 m/s (speed of sound in air) up to >2000 m/s


2000 m/s sounds like a detonation not a deflagration !!

wouldn't a small controlled detonation give more power to the bullet and require less EM ?

[Edited on 21-6-2016 by ecos]
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[*] posted on 20-6-2016 at 18:19


A detonation is just far too powerful, if using high explosives was a feasible method for launching projectiles they would already be doing it. No offense but if you're actually considering using an HE in a gun you are obviously pretty clueless about all of this.

What gives a bullet power is not the peak initial pressure but rather the average pressure through the entire length of the barrel.
Peak pressure is however what will blow up a gun.

A 9MM has about 35,000 PSI which is considered fairly high pressure for a pistol round, even a relatively weak HE can produce millions of PSI upon detonation.

[Edited on 21-6-2016 by OneEyedPyro]
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nitro-genes
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[*] posted on 21-6-2016 at 06:21


Regarding the propellant, I actually think there are many more possibilities than blackpowder or nitrocellulose. The problem is that the amount of pressure produced in the barrel of a binary fuel/oxidizer mix depends on many factors, for example type of oxidizer and fuel, oxygen balance, particle size, density, type of initiation, cardridge shape, powder load and cardridge diameter, projectile weight and projectile material etc. Even something relatively tame as blackpower comes in differnt grades, the fastest revolver grades loaded in a canon would likely destroy it was well. For nitrocellulose, a great deal of reserach has been performed to determine all of these factors to come to a reliable propellant, as the material is a high explosive in it's own right and can be detonated under the right circumstances. For many possible propellants out there, these things have not been determined thoroughly as they have never been used commercially, while some like ammonpulver have been used succesfully. Apart from the instability, sensitivity and chloride induced barrel erosion of propellants using chlorates, it would be possible to actualy use it as a small arms gunpowder, by careful consideration of all factors involved. For example considerable overfueling of the chlorate mix will likely bring barrel pressures down, so do smaller loads and possibly particle sizes. If one would be to experiment with this though, this would be just that, an experimental setup, treated as if it is a pipebomb, never to be trusted for actual use. Certainly not with welded plumbing pipe made of low grades of steel.

I would actually find it interesting if someone would build a decent standardized setup and measure projectile speeds with unconventional binary or mono propellants. For example, those containing a combination of combustible gasses and an inert light gas, like helium or excess hydrogen. Maybe a solid binary or even monopropellant may be possible, releasing much hydrogen gas upon deflageration, increasing bullet speed. Seeing some of these high nitrogen/hydrgen heterocycle EM's I've been wondering if something like that could be advantagous in producing higher projectile speeds with virually no barrel errosion. Nano aluminium coudl also help here, although would likely result in more errosion. Cost would be much higher than normal NC though...

[Edited on 21-6-2016 by nitro-genes]
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PHILOU Zrealone
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[*] posted on 21-6-2016 at 07:50


Quote: Originally posted by ecos  
In the beginning of the thread I was talking about AP as gun powder.

Quote: Originally posted by PHILOU Zrealone  
Deflagration can go over the 350 m/s (speed of sound in air) up to >2000 m/s


2000 m/s sounds like a detonation not a deflagration !!

wouldn't a small controlled detonation give more power to the bullet and require less EM ?

[Edited on 21-6-2016 by ecos]

1°) "In the beginning of the thread I was talking about AP as gun powder."
Not AP (Ammonium perchlorate) but AN (ammonium nitrate) and KClO3!

2°) Deflagration is when the burning speed of the flame front is less than the speed of sound from the front flame shock wave(into the material) if both are equal then it is a detonation.

The speed of sound in air at stp is approx 350 m/s, but in liquids like water or in solids like metals, crystals...the speed can go to several km/s. So 2000 m/s is not per se a detonation.

The speed of sound is also dependant from the heat and pressure of the material...

A space shuttle or some planes do propel themselves at speeds like Mach 7 (7* the speed of sound in air = 2450 m/s)
And those are not detonating!

3°) You are speaking of EFP (explosive formed projectiles) if you plan to use detonating EM to propel a bullet...your bullet wont be a bullet anymore, it will display totally different dynamic because it will become plastic deformed by the heat-pressure and by the air friction...making it look like wet clay, playdoh, honey or water as a function of its cohesion, hardness and elasticity.





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[*] posted on 21-6-2016 at 10:37


I have built a couple guns over the years just for experimental purposes. If I was to build another I think I would use hydraulic piston tubing/pipe, as it comes in a variety of diameters and wall thicknesses, it is seamless, made to handle high pressure and made of quality materials (in general).

Black power works, is reliable and reasonably safe, however, the extreme performance increase, relatively little fouling, etc, that comes with smokeless propellants makes them worth the extra effort in my opinion. Keep in mind it is a lot of extra effort and even after hundreds of hours I never made it all the way, but I know fairly well what needs to be done.

It is important to try new things, without some risk very little is gained, however, a careful risk assessment should be performed and if proceeding reduction of as many hazzards as possible should be basic practice.


[Edited on 22-6-2016 by Hennig Brand]




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