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Author: Subject: Detonation of Double Based Smokeless Propellants/Powder
holmes1880
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[*] posted on 26-2-2011 at 09:05


Interesting observation about flatness of Bullseye grains and density. But I think that the grains themselves are very low density. Those are light as specs of dust.
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gregxy
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[*] posted on 26-2-2011 at 11:51


The density for titegroup is around 0.9g/cc
(this is sitting in the 1lb bottle)
It seems to be quite powerful, only 5gr are needed for
a Luger 9mm.

A nicrome wire does work well, just placed among the
grains and is fast if it is thin gauge like #36. I'd rather
ignite it directly since nicrome wires are fragile.
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[*] posted on 27-2-2011 at 09:59


Quote: Originally posted by gregxy  
Smokeless powder is also difficult to ignite.

I have been working on a project to ignite it electrically.

(...........snipped for brevity)

To ignite it I tried using a 100uF cap charged to 300V, 4.5J of
energy. The powder did not ignite. Compare this to the
human body model for ESD testing 1500V @ 100pF or
around 1e-4J .



What you are dealing with has some well researched material behind it: however, it's not too easy to access. Please see USBOM Bulletin #59 C, Hall - "Investigations Into Electrical Detonation". This then leads to a rather lengthy trial during a period where Electrical Engineering was in it's infancy. Bibliography is provided in #59.

As a generality a stimulus needs to be in place to provide the need stimulus to allow for the (energetic material) to release heat through it's ("decomposition") so that one energetic stimulus is mandated to overcome a boundary for a given material to provide energy.

Heat to heat is often the least effective method if managed electrically - & here is where the challenge starts to form. Heat to provide a given stimulus is generally quite high or the energetic material quite sensitive as a DDT. Consider this example: the spit of a flame may not be nearly as hot as electrical discharge (in the case of C/D) however it exists over a greater period of time. The "spark" must be maintained at a longer time. One step away is the transference of energy (via a Joule dispersion) in the form of electrical pulse, etc. The "flame" will always beat it for time on the mark. Therefore the need for a greater level of energy and a wider dispersal area. Further still is the "EBW" concept that breaks down the given stimulus package (bridge-wire, etc): the discharge must be much more lengthy or much more powerful & here is where the complication begins with a given experimental material.

Many issues need to be studied to determine what will preform a given task and decisions need to be made as to best (most effectively) go about it. Some materials are VERY sensitive to direct electrical stimulus. Those that are more so are those that are at high risk via static release (PbN3, aluminised per/chlorates, etc). However there are those at the opposite end of the scale (nitrocellulose).

In industry the designs mfg for many "EBW" concepts are inverters with a well designed step up and they are (many times) used from a high current sources for both efficiency and portability (a truck battery as a starting point). The use of cap-discharge designs become very expensive and quite dangerous. To utilize these, the actual wire leads need to be able to effective and efficiently deal w/ high current & HV. They must be thick. For sake of safety and expense they often bed to be short and managed by encrypted transmission via small dedicated repeater stations.

To format experiments, the demand is for a "pulse" designed capacitor (bank). Even photo-flash capacitors may function (in a bank) for a stand-in. but for lengthy trials, the capacitor must be one that could handle continual "pulse" discharges. The current must be high enough so that it coincides with a certain energy dispersion formula (which I believe is in the documentation: but the end result is, it's fairly high).
Utilizing nitrocellulose is perhaps the toughest starting point.
This is also why the electrical generator (blast-box, push, pull, or twist) has been with us so long. It gives a high current output for a longer time with the simplest form of design. The same could be said of a "pull starter" from a lawn mower, ect.

Experiments conducted without rather sophisticated recording equipment is a real challenge. Nearly 80+ years ago there was a device where a "spoon-like" metallic device held a testing material and another metallic "probe" was raised and lowered toward the material resting in the "spoon". various amounts of electrical energy were tested to determine what would provide the need stimulus for some materials to detonate, others to deflagrate.

[Edited on 27-2-2011 by quicksilver]




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[*] posted on 27-2-2011 at 12:17


Quote: Originally posted by quicksilver  
What you are dealing with has some well researched material behind it: however, it's not too easy to access. Please see USBOM Bulletin #59 C, Hall - "Investigations Into Electrical Detonation". This then leads to a rather lengthy trial during a period where Electrical Engineering was in it's infancy. Bibliography is provided in #59.

not too easy to access.

Google.com/books worked for me.

[Edited on 27-2-2011 by The WiZard is In]
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[*] posted on 1-3-2011 at 09:05


@ gregxy :
Here are some of the actual technical work-ups on energy dist, design, & complementary. It's pretty much as recent as i have & hopefully should provide answers to a lot of issues.

Attachment: ccl3_electronics_detonation.pdf (337kB)
This file has been downloaded 1201 times





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[*] posted on 22-4-2020 at 16:41
Ball milled smokeless powder


I will be attempting to ball mill Accurate Nitro 100 powder (the fastest double base I could find) and setting off the product in various ways (open flame, confined open flame, detonated, detonated while confined).

I plan to use ceramic media and a remotely controlled ball mill of course. Even then I’ll be at least 100 meters away and behind cover because I may basically be setting off a pipe bomb! For detonation I’ll try dextrinated lead azide, with and without an ETN booster, as well as NHN.
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[*] posted on 26-4-2020 at 20:24
Ball milled smokeless powder


I’ve created a thread asking about the idea of ball milking smokeless powder and think it’s related to this. We all know smokeless powder is designed to burn slower via use of additives and particle shapes, so I wonder if density, sensitivity, and detonation velocity/pressure wave duration could be optimized if ball milled smokeless powder was wet pressed and dried?

Let me be clear that I have not tried ball milking smokeless powder and am unsure of the safety. Obviously lead or ceramic media will have to be used (and are used safely to ball mill black powder) but it’s not been tried. I am planning a serious of experiments with ball milled powder as soon as I can get to my vacation home and set up a remote ball mill outside (I have plenty of room to do this safely, and will proceed under the assumption that the ball mill will violently explode!)

I’ll add in a density experiment. Off the top of my head, I’m thinking of comparing unmilled powder, milled powder, pressed milled powder, and milled/unmilled powder mixed with microspheres you decrease density further than unmilled. The main obstacle I foresee is designing a reliable testing procedure that will be able to detect the likely small differences in performance.
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