Smokeless Powder as dangerous as black powder?

[dbooksta]

The Feds just put out this notice suggesting that smokeless powder and blackpowder substitutes are "common bomb-making materials," right alongside black powder.

 

My understanding was that black powder is in a class of its own because it can detonate, whereas smokeless and substitutes cannot. Can someone clarify?

 

Granted, I suppose one can make a "bomb" out of any pressure vessel and a solid/liquid that can be stimulated to chemically convert to a gas. But I've never heard of a magazine requirement for smokeless powder like there is for blackpowder storage. Is that just because smokeless requires confinement to even deflagrate, whereas blackpowder deflagrates without confinement? Is blackpowder capable of supersonic deflagration?

Edited December 13, 2013 by dbooksta

[Mortartube]

I have never heard of BP detonating. Deflagrating quicly, yes, but never detonating.

[Arthur]

I suspect it's what you do with a product that makes it more or less dangerous. A pile of BP burning in the open is a different animal to the same weight of BP in a ball wrapped with string.

[dbooksta]

Fair enough. Maybe I should restate the question: What is the characteristic of BP that makes it more dangerous than smokeless powder? Like I said, the ATF certainly seems to think it's more dangerous since they require licensed magazines for storing commercial quantities of BP, but not of SP.

 

I know smokeless powders are designed to deflagrate at controlled rates. Is the practical distinction between BP and SP removed if you grind or dissolve the SP, thus removing the coatings and grain structure that control burn its rate?

[mike_au]

 

My understanding was that black powder is in a class of its own because it can detonate, whereas smokeless and substitutes cannot. Can someone clarify?

 

 

I have heard this a lot from shooters as well (often stated as "SP burns, BP explodes"), after much searching I have been unable to find anything to actually support the claim that SP cannot detonate claim and several points that dispute it. And while I have heard anecdotal references to BP detonating, it has always been in incredibly large quantities (hundreds of kg at least) and I've never heard of any actual measured and documented evidence.

 

Many (most?) other countries consider both to be explosives and have similar storage requirements.

 

SP is more likely to have stabilisers and/or burn rate modifiers that may prevent it from going up from small ignition sources like sparks, obviously that doesn't apply to BP substitutes or else they wouldn't be any good for flint/wheel/match lock guns. While these may make it a little harder to ignite, they don't really prevent it from going up pretty quickly once it has started. The reason reloading manuals specify a minimum load is because if the case is under filled you can get flash over (this is one of the situations where there is a reasonable amount of evidence to suggest that SP does in fact detonate) burn rate modifiers don't prevent that.

 

The only reasons I can think of for SP to be less tightly controlled than BP are that very slightly reduced chance of ignition, old wives tales about "BP exploding" (when have firearms or explosives laws ever been about what is actually more dangerous, rather than about public opinion), and political reasons arising from the US's 2nd amendment, combined with the fact that antiques actions aren't considered firearms.

[dbooksta]

The reason reloading manuals specify a minimum load is because if the case is under filled you can get flash over (this is one of the situations where there is a reasonable amount of evidence to suggest that SP does in fact detonate) burn rate modifiers don't prevent that.

 

Little OT, but since reloading happens to be one of my areas of expertise I need to debunk this persistent myth of "secondary explosive effect" being related to detonation or extraordinary decomposition of smokeless powder. The phenomenon is well-known and unfortunately easy to reproduce: Loads with slow powders that don't cover the flash hole can result in the primer "flashing over" the powder and pushing the bullet into the lands before the powder begins to build pressure. Starting a bullet stuck on the lands takes more pressure, and in some cases it can fail to dislodge and cause a catastrophic failure of the gun action. It sure feels like a "detonation" to the shooter, but it's physically and chemically no different from firing into any other obstructed bore.

 

 

More on topic: I have test-fired large charges of TiteGroup, one of the fastest smokeless powders, and for the same powder mass it produces nothing like the explosive force of a pressure vessel loaded with BP.

Edited December 14, 2013 by dbooksta

[Xtreme Pyro]

More on topic: I have tested pipe bombs using TiteGroup, one of the fastest smokeless powders, and for the same powder mass they produce nothing like the explosive force of a pipe loaded with BP.

 

Pipe bombs? We make fireworks. Not bombs, or any other dangerous explosive that will create large amounts of shrapnel that can kill or injure you, or someone else. Not too moderate, but that kind of thing isn't gonna fly here, just a fair warning.

Edited December 14, 2013 by Xtreme Pyro

[mike_au]

 

Loads with slow powders that don't cover the flash hole can result in the primer "flashing over" the powder and pushing the bullet into the lands before the powder begins to build pressure. Starting a bullet stuck on the lands takes more pressure, and in some cases it can fail to dislodge and cause a catastrophic failure of the gun action.

 

 

I have also heard of that explanation, do you have any reliable sources documenting it?

 

You might want to edit the end of your post and look around a bit, as Xtreme said, further comments like that won't win you any friends here.

[LambentPyro]

Pipe bombs? We make fireworks. Not bombs, or any other dangerous explosive that will create large amounts of shrapnel that can kill or injure you, or someone else. Not too moderate, but that kind of thing isn't gonna fly here, just a fair warning.

Nicely said, I think he deserves a ban for sure. That kind of shit is strictly prohibited. This hobby is fearful enough to lots of people, when you put that word onto a forum that discusses explosives and fireworks, it gets suspicious and creates a bad name for our hobby. Federal agencies are constantly monitoring anything that they can find evidence to a potential mass threatening situation.

 

See how I avoided any words involving what certain groups are categorized as? Or what dbooksta said about what he made? As a fireworker, I never say any words that relate to the 'bad side' of making explosives, not written, not said, KEEP IT OUT OF YOUR VOCABULARY. I highly suggest that to everyone.

Edited December 14, 2013 by LambentPyro

[dbooksta]

 

**** bombs? We make fireworks. Not bombs, or any other dangerous explosive that will create large amounts of shrapnel that can kill or injure you, or someone else. Not too moderate, but that kind of thing isn't gonna fly here, just a fair warning.

 

Point taken; I apologize. I was using it as a term of art. Let me replace it by "vessel designed to measure burning rates and characteristics under confinement." I don't have a lab equipped to precisely measure those characteristics, but I was curious as to whether SP in commercial form has useful pyrotechnic properties, and so I did controlled vessel tests as a rough comparison against BP. Furthermore I wouldn't recommend metal vessels for this: solvent-welded schedule 40 PVC avoids metal shrapnel.

 

NB: I haven't tested this, but we do know that if SP is milled it burns much more quickly, so one possibility is that when the grain structure is destroyed it does become as dangerous as (or more dangerous than?) BP. Since SP is mostly nitrocellulose (plus nitroglycerin if double-base) I guess the question is whether those high-energy compounds can be readily separated from the stabilizers, and if so whether NC is a primary HE, or at least whether it can burn more quickly than BP. Again, not something I'm interested in actually trying, since BP is cheaper, and not something I'm asking for instructions on. I'm merely curious because the Feds just lumped SP together with BP and I thought SP was inherently safer and couldn't be put to nefarious uses (at least not by someone who wouldn't already have the skills and means to produce HE more cheaply and easily).

Edited December 14, 2013 by dbooksta

[dbooksta]

 

I have also heard of that explanation, do you have any reliable sources documenting it?

 

I got that explanation firsthand from one of the senior techs at Hodgdon powder company. He noted that they can produce a consistent pressure spike associated with flashover on their instrumented barrels. Whether the phenomenon actually results in an "explosion" is a function of how the bullet lodges in the bore, whether the powder is slow enough to ignite that the bullet comes to a full stop, and then whether the action can vent excessive pressures without failing. (Fortunately a lot more modern actions are designed to vent instead of explode. Also there are bulkier powders available now for people who want to produce light loads.)

[Mumbles]

Lambent, please worry about yourself and leave the moderating to the people actually in charge here.

 

dbooksta, I suggest you rethink some of the things you're doing. Using metal or PVC pipe will result in dangerous shrapnel is all cases. Any discussion of pipe bombs, no matter what the pipe is really made from, isn't going to be well recieved by the members here and really isn't allowed. Destructive devices have no part in legitimate pyrotechnics.

 

Anyway back on topic. Commerical blackpowder being used for sporting, recreation, or cultural uses only needs to be stored in a magazine if in quantities over 50lbs. From a little reading, it appears that smokeless powders have a vaguely similar regulation. It's NFPA regulations, so it's dependent upon what your individual state has adopted. NFPA495-85

[LambentPyro]

Lambent, please worry about yourself and leave the moderating to the people actually in charge here.

My apologies, I am very sensitive when it comes to topics like this and get pretty ticked off.

[dbooksta]

dbooksta, I suggest you rethink some of the things you're doing. Using metal or PVC pipe will result in dangerous shrapnel is all cases. Any discussion of pipe bombs, no matter what the pipe is really made from, isn't going to be well recieved by the members here and really isn't allowed. Destructive devices have no part in legitimate pyrotechnics.

 

I apologize again; I didn't mean to suggest I'm interested in DDs. I guess the original question sort of points in that direction, since otherwise the govt wouldn't have suggested it, but again I'm not looking for instructions, just wondering if the chemistry supports what the govt suggested since it is at odds with my prior knowledge and experience.

 

Your point that PVC can produce dangerous shrapnel sent me on a search I haven't found clearly answered: What safety measures can and should be taken when ground-testing fireworks? Actually that seems like an important safety question so if you don't mind I'll start it as a separate topic.

[BurritoBandito]

Please allow me to preform a bit of necromancy on this thread...

Both Alliant Powder's "Unique Smokeless Powder" and "Reloder 22 Smokeless Magnum Rifle Powder" appear to detonate when struck with a hammer. It may merely be them confining between the hammer and surface on which they're resting, but an audible crack is definitely heard. Given the fact that they are both double based powders with NC and NG being the primary ingredients a detonation would not surprise me in the least.

 

Sorry to bring up such an old thread, but I wanted to contribute my experience with smokeless powder.

[Jakenbake]

Hmm i know what I'm going to do with my pound of unique when I get home from work today.

[BurritoBandito]

The easiest way I've found to test this is to use acetone to form a single mass of the powder so it isn't dispersed when you hit it. Edited June 16, 2014 by BurritoBandito

[Mumbles]

That might be causing it to become impact sensitive. When you dissolve double base powders into acetone, the NC and NG can separate.

[dbooksta]

Interesting. Is there a hammer test that can confirm it's a detonation? All the tests for HE I'm familiar with look for dents on metal witness plates. E.g., use a soft enough hammer head that if you hit the plate without powder present there's no dent but with the powder sample it leaves one?

 

I have plenty of double-base powders, but not those two. Of course like Mumbles said by the time you've dissolved them in acetone you've at the very least destroyed the grain structure so the only other difference you'd see is in the small proportions of chemicals added as coatings and to inhibit flash and corrosion.

[BurritoBandito]

It can be done with the granules/flakes as well it's just hard to keep the pile together while you strike it.

[dagabu]

It can be done with the granules/flakes as well it's just hard to keep the pile together while you strike it.

 

Very early on, I made a drop hammer impact tester to test impact sensitivity on all my comps, it was easily built and eventually gave it away to another pyro looking to test his comps. After maybe 1000 or so tests, I got smart and just used a small piece of masking tape (face up) to hold the comp in place. I found that it was the "pinch" that mattered, not the absolute placement, the weight or 'perfect' pinch points. In the very end, I settled on a masking tape packet of said comp and tested them all using a small hollow tube and placing 1gr in the tube using a funnel and placing another tab of masking tape over that one.

 

Perfect? Heel no! VERY good at determining sensitivity? HEEL YES!

 

You can make an even more basic drop hammer tester yourself with a hammer, a couple 2x4's, a steel plate and some know-how.

[BurritoBandito]

Interesting. Is there a hammer test that can confirm it's a detonation? All the tests for HE I'm familiar with look for dents on metal witness plates. E.g., use a soft enough hammer head that if you hit the plate without powder present there's no dent but with the powder sample it leaves one?

Not to my knowledge. Maybe with a very large hammer and sample of smokeless powder. I just don't think that smokeless powder is brisant enough to do much to a witness plate. I could be wrong though.

[TheExplosionist]

Smokeless is much more dangerous as it produces much higher pressures.

[BurritoBandito]

Only if you have it under pretty heavy confinement.

[dagabu]

Agreed. I took a class years after the Columbine shooting and the DHS demonstrated powder confinement, destructive power and a new thing called "evacuation in place". Simply put, it takes heavy confinement for smokeless powder to cause a brisiant blast while BP can become brisiant inside a paper container.

 

BP was by far a bigger risk to schools compared to smokeless... Unless contained in a well made pipe, you just cant get the flame front to propagate fast enough with smokeless.