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Author: Subject: Unconventional Shaped Charges
enhzflep
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[*] posted on 13-5-2007 at 23:08


Yes indeed Sir, I have used these very things in the past. US$50 is a VERY good price. We used to pay around Aus$80 for just a brass doming block - never mind the punches, or the fact this one is carbon steel. For the equivalent in Aus we're looking at 300 bucks...

As for AXTs idea, I don't see why it wouldn't work. Jewellers use a very similar arrangement for reducing the size of plain wedding bands. Obviously, rings are quite narrow or short compared to a piece of tube to be used for making cones, but the rings did indeed come out conical.

I'd be inclined to think you'd need a number of different dies, that changed angle. So you would have a slight reduction at the start of the series and a rather pointed mandrel (as the image above) at the end of the series. My guess is that you'd get away with perhaps 5 or six punch/die pairs.

Definitely worth investigating..
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tito-o-mac
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[*] posted on 16-7-2007 at 06:16


Hey check this out. It's rather similar to a shaped charge but it's an Explosively Formed Penetrator! An explosively formed penetrator (EFP), also known as an explosively formed projectile, a self-forging warhead, or a self-forging fragment, is a special type of shaped charge designed to penetrate armour effectively at stand-off distances.

Here's the description: A conventional shaped charge generally has a conical metal liner that projects a hypervelocity jet of metal able to penetrate to great depths into steel armour; however, in travel over some distance the jet breaks up along its length into particles that drift out of alignment, greatly diminishing its effectiveness at a distance.

Whereas for the EFP, on the other hand, has a liner in the shape of a shallow dish.The force of the blast molds the copper plate into any of a number of configurations, depending on how the plate is formed and how the explosive is detonated. Sophisticated EFP warheads have multiple detonators that can be fired in different arrangements causing different types of waveform in the explosive, resulting in either a long-rod penetrator, an aerodynamic slug projectile or multiple high-velocity fragments. A less sophisticated approach for changing the formation of an EFP is the use of wire-mesh in front of the liner: with the mesh in place the liner will fragment into multiple penetrators.

As a rule of thumb, an EFP will perforate a thickness of armour equal to only about the diameter of its charge, whereas a typical shaped charge will go through six or more diameters.

[Edited on 16-7-2007 by tito-o-mac]

Improvised_explosive_device_explosively_formed_penetrator_Iraq.jpg - 65kB
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tito-o-mac
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[*] posted on 16-7-2007 at 06:18


Formation of Explosively Formed Penetrator. here's a short clip: http://www.youtube.com/watch?v=JfCCXglrJuo


[Edited on 16-7-2007 by tito-o-mac]

Explosively_formed_penetrator.gif - 13kB
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MRUD
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[*] posted on 17-7-2007 at 11:44


Hi there.
I'm allways on this kind of penetrator, i have done also some tries with them.

The very first try wasn't a success, to thin not to blown apart




Target was a 5mm thick steel plate.

The second attempt wasn't a success too.




At this time, i think, the liner was to thick.

So my next project is with this liner.
2mm thick
50mm diameter
made from copper



hope getting better results with this one.

So long, hope you understand what i wanna tell you
Greetings from Germany.

MRUD
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tito-o-mac
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[*] posted on 19-7-2007 at 02:48


Can you explain more about picture 3 from top?

Do you have any measurment of the penetration? Anyway, just wanted to ask you something: when the explosives were detonated, did the container produce any shrapnel or stay intact? One more thing: the range from which you fire from will affect the shape of the charge, also the penetration. Too close and immature formation of the charge will reduce the penetration!

Here's a suggestion: A less sophisticated approach for changing the formation of an EFP is the use of wire-mesh in front of the liner: with the mesh in place the liner will fragment into multiple penetrators. Also use aluminium for greater penertration against concrete targets.

BTW remeber to show us your pics:D ( and if maybe a video)
Anyway all the best :)
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tito-o-mac
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[*] posted on 19-7-2007 at 02:50


The charges are generally cylindrical, fabricated from commonly available metal pipe, with the forward end closed by a concave copper or steel disk-shaped liner to create a shaped charge. Explosive is loaded behind the metal liner to fill the pipe. Upon detonation, the explosive projects the liner to form a projectile at a velocity well over 1 km/s, depending on the design and type of explosive used. This slug is projected towards the target at about two kilometres per second. The chief advantage of the EFP over a conventional (e.g., conical) shaped charge is its effectiveness at very great standoffs, equal to hundreds of times the charge's diameter (perhaps a hundred meters for a practical device).

It can travel up to perhaps 1000 charge diameters (CDs) before its velocity becomes ineffective at penetrating armour due to aerodynamic drag, or successfully hitting the target becomes a problem. The impact of a ball or slug EFP normally causes a large-diameter but relatively shallow hole, of, at most, a couple of CDs.

Try to beat the record of 100mm penetration MRUD!!:o

[Edited on 19-7-2007 by tito-o-mac]

[Edited on 19-7-2007 by tito-o-mac]
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MRUD
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[*] posted on 19-7-2007 at 08:54


Hi tito-o-mac.

At first, picture 3 schows the result of the first EFP i have build.
The liner in my first was made from zinc 0.8mm thick and i knew that this liner would never build any kind of projectile. Was only for testing, what would happen, with the liner. Means, is the impakt at the target far strewn or focused at the aimed point of impakt. So i can improve the following liners.
Charge was about 45g PETN.
Diameter of liner ~ 5cm
Distance around 10cm
As you can see, the liner wasn't intact at time of impact.

And second, i don't think i'm able to penetrate more than 2cm coused by the quantity of PETN i normaly use.
But 100mm is a fucking nice thick steel plate, who had done these? or is this a millitary build EFP?

Greetings

MRUD
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tito-o-mac
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[*] posted on 19-7-2007 at 21:56


Sorry, I was referring to a military build EFP. Remember the very first post the gut used ANNMSA ( I don't know whats that) but I think a Ammonium Nitrate NitroMethane Alumnium (ANNMAL) should also work, cos' its more readily available to obtain and if you do not want to use your PETN:)

Errr... I'm not too sure about the distance of 10cm. It seems a bit short to me though! One more thing: is the 2 cm liner thick enough to not disintegrate with the force of the explosion? Maybe a thicker liner would work.

Very good job anyway!:P;)
Greetings and all the best for the next project!

[Edited on 20-7-2007 by tito-o-mac]

weapon_graphicfull_4.jpg - 43kB
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MRUD
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[*] posted on 22-7-2007 at 12:48


All my charges based on try and error, the only reference i have are some patents and some suggestions from the internet.

So i hope the third liner will do a better job as the 2 before.
The first one disintegrated (he was to thin), the second one didn't, but he was to thick to form up an projectile (4mm of thickness, you can see, the hole in the plate is the same diameter as the liner had)
So i decided to try a copper liner between this thickness.
I give him a try. Also i can increase the distant couse this liner is formed more precisely as the 2 before, think, 20cm will worke to hit such a small target.
Hope to get the time to set up the charge of next weekend.
Then we can discuss the result.

Greetings

MRUD

[Bearbeitet am 22-7-2007 von MRUD]
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tito-o-mac
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[*] posted on 23-7-2007 at 02:58


Did you know there is a way to control the shape of the EFP? All u need to do is stick a tube with the desired shape you want at the centre of the copper plate, and it will mould in to the shape.

So far, got any more pics to show us on your progress?

[Edited on 23-7-2007 by tito-o-mac]

Attachment: Segmented kinetic energy explosively formed penetrator assembly - US Patent 6510797.mht (80kB)
This file has been downloaded 1185 times

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[*] posted on 28-7-2007 at 09:24


Here we go, EFP mark III.

I think, it's an nice result i got. Not the best, but better than expected

Target was a 5mm thick steel plate, distance to target around 40cm.
Got a nice hole in the plate, and the force was strong enougt to deform the 2cm plate behind.




At the target site


result





Greetings

MRUD
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E-tech
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[*] posted on 30-7-2007 at 09:58


Very well done, MRUD!
A few questions- how are you forming the copper? What is the final weight of the copper (before detonation, of course), and, what angle is the copper cone (again, before detonation)?
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[*] posted on 30-7-2007 at 12:53


The copper plate was formed with a "matritze" (don't know the english word) a picture will show you, what i mean. He was pressed between this to.


Liner weight was 37g, angle around 30°
And i (wasted) used 56g of PETN at this EFP.
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UnintentionalChaos
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[*] posted on 30-7-2007 at 13:10


The word you are looking for is a "die" Very nicely done.



Department of Redundancy Department - Now with paperwork!

'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Marsh
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[*] posted on 8-8-2007 at 18:25


Have you thought about using a small shaped cavity between the copper plate and the energetic so that Monroe forces act on the plate, to somewhat shape it into a longer projectile? Then again, jet formation may penetrate the plate too easily.

Or, what about using a waveshaper in your energetic to form the plate to a more desireable shape?

Don't really know much about EFPs, just throwing some ideas out there.
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[*] posted on 31-8-2007 at 07:05


MRUD have you thought about in your next test ( if you do one ) attempting a long standoff for the EFP ( say a couple of meters? ).

Also I think it was here that someone asked why in rockets and certain military weapons that the shaped charge liner had a trumpet shape, I lost the reference but it was a military brochure for a rocket weapon system that said the trumpet shape creates a better BHE ( Behind Armour Effect ), basically I think that means it does more damage on the inside of the tank once it penetrates the amour.
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[*] posted on 18-11-2007 at 02:41


[Edited on 21-11-2007 by franklyn]

Optimimal Shaped Charge Characteristics.gif - 51kB
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[*] posted on 19-11-2007 at 22:11


Downloaded ICEOWS, but I can't open the .ice file. Any suggestions?
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[*] posted on 21-11-2007 at 03:32


Franklyn, is it kind of joke? If so, it's not funny. I spent several hours to find a program to unpack your *.ice archive. Maybe you'll share the program you used to pack the files?
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enhzflep
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[*] posted on 21-11-2007 at 03:57


Ha, ha - nice one HMTD.
Spent several hours looking for an ACE unpacker??!

If you're serious, and you can't find an opener, try IZArc. Perhaps that will open these files - it definitely supports ACE files,
I'm just not sure if it will touch these files, in light of Bert's troubles.

Anyhoo, it's free and small.
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[*] posted on 21-11-2007 at 06:51


enhzflep , thanks but no thanks.

Do you see the difference between *.ACE and *.ICE files? Tell me - have you downloaded the file and unpacked it with IZArc(btw,good free program)? If so, then please tell me how,mine IZArc ignores the file even renamed to *.ACE. I'm just curious, where Franklyn got such unusual and rare(maybe very-very old) file format? There are so many free and good formats.
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[*] posted on 21-11-2007 at 12:51


Very Sorry about that , I assumed that most full feature
compression utilities such as Winrar and freeware
such as 7z are compatible , guess not.

Quote:
Originally posted by franklyn
Oops I had not noticed that these are available for download here
from the First CD of the Los Alamos Technical Reports Collection.

http://www.sciencemadness.org/lanl1_a/mainindex.html
Near the top of the list

LOS ALAMOS SERIES ON DYNAMIC MATERIAL PROPERTIES
PHERMEX Data Vols I , II , III
PHERMEX ( Pulsed High Energy Radiographic Machine Emitting X-rays )

LASL Phermex Data, Volume 1
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph1.pdf
LASL Phermex Data, Volume 2
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph2.pdf
LASL Phermex Data, Volume 3
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph3.pdf
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enhzflep
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[*] posted on 21-11-2007 at 17:29


Well,

HMTD
(goes to get reading glasses and 1/2 eaten plate of humble pie)
Sorry about that HMTD. I'm _really_ having a dumb day today. Dunno how I misread that. sorry.

Frankyln,
Thanks for the extra info - curious bit of errata about the vunerabilities, Downloading the pdfs now. Thanks mate.

S.
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[*] posted on 22-11-2007 at 13:37


Enhzflep

It happens.

Frankyln, thanx for interesting pictures. Those people had so much fun 40 years ago. I can only imagine how much U238, Be, Hg,Pb were dispersed in these experiments.

[Edited on 11/23/2007 by HMTD]
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[*] posted on 13-12-2007 at 13:05


Here is my experience with a fully improvised shaped a charge.

A body was made from Actimel:
http://www.actimel.com/intl/img/actimel_varieties_visu4.jpg

It was cut right above and under that orange sticker, so I got a tube.

A 40W-E14 light bulb was cut in half and inserted in tube made from actimel. That was my liner.
A bulb looked like this :
http://www.bulbman.com/images/e14bccl101.jpg


A standoff was made from a toilet paper roll, and body was filled with ~80g cast PETN/RDX/Wax.

A detonator was made from 4g PETN/RDX and 0.5g AgN3

Here are the results:
http://shrani.si/f/1Y/jI/SW3cyoB/bw.jpg
http://shrani.si/f/1n/dL/2EXCr8ko/bw2.jpg
http://shrani.si/f/1h/9J/2Fxr6I1F/bw3.jpg
http://shrani.si/f/3A/z3/bI9kS5Y/bw4.jpg
http://shrani.si/f/o/sj/2dwSsoyy/c.jpg
http://shrani.si/f/3A/4q/42DZ790E/c2.jpg
http://shrani.si/f/3s/cP/1mtn0k7X/c3.jpg
http://shrani.si/f/2r/mi/1exyD26o/c4.jpg

PS. Sorry about the first B&W images.
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