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Explosive vs Gunpowder
- Thread starter C7AR15
- Start date
An explosive goes from a solid to a gas instantly(well in microseconds) but does not burn to do it. Smokeless gunpowder(BP is a low grade explosive) doesn't explode. It burns really fast.
Biggest difference between 'em is the speed at which they do it. Mind you, uncontained BP just burns too. An explosive like Nitroglycerin doesn't need to be contained to explode.
Biggest difference between 'em is the speed at which they do it. Mind you, uncontained BP just burns too. An explosive like Nitroglycerin doesn't need to be contained to explode.
These things are measured by burning or combustion rate . Firearms require the production of large amounts of expanding hot gases that propel the bullet.
High explosives create forces at a much higher speed . There are some very interesting videos where you can see the destructive forces of rapid movement of the shock waves.
Explosive forces can also be focused with incredible effect as in some weapons like the old Rockeye bomblet to punch a 1/4"hole through 12" of steel as used in Viet Nam . That idea actually was developed in WWI as the British Limpet mine used against ships.
High explosives create forces at a much higher speed . There are some very interesting videos where you can see the destructive forces of rapid movement of the shock waves.
Explosive forces can also be focused with incredible effect as in some weapons like the old Rockeye bomblet to punch a 1/4"hole through 12" of steel as used in Viet Nam . That idea actually was developed in WWI as the British Limpet mine used against ships.
Well, they already gave you that answer...
And it is why more and more local gun shops are getting away from carrying actual black powder. Because it's labeled as an explosive, there are hazmat charges, and other restrictions on it.
Hence why you can see Pyrodex sitting out on the shelf at Wally World...
And it is why more and more local gun shops are getting away from carrying actual black powder. Because it's labeled as an explosive, there are hazmat charges, and other restrictions on it.
Hence why you can see Pyrodex sitting out on the shelf at Wally World...
The above information is confused. Gunpowder is an explosive. Black gunpowder and old fashioned blasting powder and firecracker powders are called low explosives because they release energy by deflagration, a form of combustion propagated by a flame front, even if it is quick. High explosives release energy by detonation, a form of combustion propagated by a shock wave traveling at the speed of sound in the explosive material mass, which is much faster than flame front speed of travel, so it releases all the energy in the explosive much more suddenly. Indeed, the definition of the difference between detonation and deflagration is that the latter always happens below the speed of sound in the explosive, while the former always happens at or a bit above the speed of sound in the resting material (due to compression and temperature rise from its own shock wave increasing the speed of sound in it, at least for a short distance). The measure of explosive suddeness is called brissance, and is determined by the ability of the explosive pressure wave front to shatter particles of sand.
Any explosive contains a certain amount of potential energy. That energy is released by injecting enough kinetic energy into the material to break up its constituents, freeing oxygen to recombine with the fuel molecules into new molecules, like carbon monoxide and dioxide and nitrogen oxides and di-hydrogen oxide (water), that have lower potential energy. The potential energy difference in the two states is what is released. Kinetic energy may be injected either by sudden shock or by heat. Heat tends to initiate only deflagration because heat doesn't travel fast, but there are conditions in which heat alone can trigger detonation locally which then snowballs to go throughout the explosive mass. Indeed, the explosives we use as detonators are exceptionally sensitive to having detonation initiated by heat alone. Nitroglycerine also has that quality, which is why it is dangerous to handle without a lot of temperature controls. Detonators make both heat and a shock wave.
Smokeless powder is a funny animal in that it is a high explosive material, but one that is constrained to deflagrate rather than detonate through the use of granulation (granules don't carry a shock wave well) and deterrent chemistry. The firing of a gun is, nonetheless, an explosion; it is just a controlled and directed one brought about through controlled deflagration, whether by black powder or smokeless powder.
Any explosive contains a certain amount of potential energy. That energy is released by injecting enough kinetic energy into the material to break up its constituents, freeing oxygen to recombine with the fuel molecules into new molecules, like carbon monoxide and dioxide and nitrogen oxides and di-hydrogen oxide (water), that have lower potential energy. The potential energy difference in the two states is what is released. Kinetic energy may be injected either by sudden shock or by heat. Heat tends to initiate only deflagration because heat doesn't travel fast, but there are conditions in which heat alone can trigger detonation locally which then snowballs to go throughout the explosive mass. Indeed, the explosives we use as detonators are exceptionally sensitive to having detonation initiated by heat alone. Nitroglycerine also has that quality, which is why it is dangerous to handle without a lot of temperature controls. Detonators make both heat and a shock wave.
Smokeless powder is a funny animal in that it is a high explosive material, but one that is constrained to deflagrate rather than detonate through the use of granulation (granules don't carry a shock wave well) and deterrent chemistry. The firing of a gun is, nonetheless, an explosion; it is just a controlled and directed one brought about through controlled deflagration, whether by black powder or smokeless powder.
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Unclenick has covered it well, as always. http://www.firearmsid.com/Feature%20Articles/McCord_gunpowder/ Interesting read.
It depends on who's definition you are looking for...
The BATFE defines black powder as an explosive and modern smokeless powder as a flammable solid. A 1 lbs can of black powder can explode. A 1 lbs can of smokeless powder will burn.
You need pressure and a confined space to get the efficient burn that makes smokeless powder ideal for firearms. However that doesn't mean smokeless powder is not an explosive. If you take a large rifle case and fill it full of a fast burning smokeless powder and fire it (Do not do this!) the effect will be the same as an explosion. Under pressure the burn rate of smokeless powder increases.
The BATFE defines black powder as an explosive and modern smokeless powder as a flammable solid. A 1 lbs can of black powder can explode. A 1 lbs can of smokeless powder will burn.
You need pressure and a confined space to get the efficient burn that makes smokeless powder ideal for firearms. However that doesn't mean smokeless powder is not an explosive. If you take a large rifle case and fill it full of a fast burning smokeless powder and fire it (Do not do this!) the effect will be the same as an explosion. Under pressure the burn rate of smokeless powder increases.
JeepHammer
Moderator
The original discription of explosive is velocity sufficient to case catastrophic failure.
Found it in a DuPont explosives manual from 1961 but I'm not sure it applies since we are talking controlled burns that do not cause a failure of any kind.
Found it in a DuPont explosives manual from 1961 but I'm not sure it applies since we are talking controlled burns that do not cause a failure of any kind.
ShootistPRS
New member
If you would really like to be confused look up the properties of primary and secondary explosives. Black powder and nitroglycerin are both primary explosives while RDX and its derivatives are considered secondary explosives.
The products stability is part of the definition but its means and speed of detonation is just as important.
The products stability is part of the definition but its means and speed of detonation is just as important.
A high explosive (it is the technical term) contains a in itself all components for "burning" or detonating. It also produces a shock wave when detonating which makes it useful in other applications. Gunpowder does not produce a shock wave when burning. There are instances of small amounts of smokeless powder in a large container detonating and producing a shock wave. When this happens in a firearm, the results can be devastating for the firearm. Years ago when I was starting to reload, I was interested in "small" loads, and was concerned about the problem of detonation. I'm afraid that no resource I've tried have resolved the issue, and it still concerns me. Reliable and repeatable results seem nowhere to be found.
willr
willr
explosives are exactly that, explosives, gunpowder on the other hand is a propellant. hdbiker
The BATFE defines black powder as an explosive and modern smokeless powder as a flammable solid. A 1 lbs can of black powder can explode. A 1 lbs can of smokeless powder will burn.
Those are legal definitions used mainly to determine how things have to be classified for storage and transportation. Technical definitions are broader.
The original discription of explosive is velocity sufficient to case catastrophic failure.
Found it in a DuPont explosives manual from 1961
The were explosives before 1961, but I like that definition. For example, you could say explosive growth of urban areas can cause catastrophic societal failure. A meteor has enough velocity to cause catastrophic failure of anything it hits, and the impact produces a shockwave and enough heat to expand the air some. But it is worth noting the meteor itself is not made of a material the law would call either an explosive or a propellant.
The Oxford dictionary's definition of explosion is:
"technical A violent expansion in which energy is transmitted outwards as a shock wave."
This is also very general. For example:
A firecracker is an explosive, but a tiny one, like a lady finger, doesn't usually cause catastrophic failure of anything more than the paper it is wrapped in. The sound it produces is its shockwave, same as sound is for a gun shot.
A high explosive (it is the technical term) contains a in itself all components for "burning" or detonating.
So does a low explosive. The difference is that high explosive substances contain them all in the same molecule, while the low explosive is a mixture of different fuel and oxidizer molecules.
Smokeless powder is made primarily of high explosive molecules; nitrocellulose and often nitroglycerin in a nitrocellulose matrix, which renders it stable. The reason the powder can be made to deflagrate rather than detonate is as I explained earlier; granulation and deterrent additives. But that's a case of altering the explosive to change its behavior, not of making it something other than an explosive. You can shave pieces of TNT off a block and light it with a match to serve as campfire kindling. It will deflagrate just fine as long as there isn't a shockwave initiator (a detonator) or a mass so huge that it detonates spontaneously during deflagration. But it is still a high explosive. The fact that it can deflagrate doesn't change its explosive reality at the molecular level.
Another point is that while black powder is not normally detonated nor is a powerful explosive when burned in the open, if you collect enough of it in one place the powder mass behaves more like a fluid and can be detonated by a stick of dynamite that creates a shockwave that travels right through the granular structure. The required mass, however, is measured in tons, IIRC, so this isn't a likely event for the handloader. A good example though, is a black powder plant explosion. Even with barrels separating quantities and nothing producing a high level of confinement, that has happened. So have smokeless powder plant explosions.
Re: “Those are legal definitions used mainly to determine how things have to be classified for storage and transportation. Technical definitions are broader.”
That was my point. The original post assumed that gunpowder was not an explosive. Depending on who’s definition you are using modern smokeless propellants can be classified as either an explosive or not. The original post also states that black powder explodes while gun powder burns. This is correct if you view the question as it relates to the BATFE definition in regards to storage and transportation. I’m not trying to argue, but to clarify that the correct/best answer depends on the context.
That was my point. The original post assumed that gunpowder was not an explosive. Depending on who’s definition you are using modern smokeless propellants can be classified as either an explosive or not. The original post also states that black powder explodes while gun powder burns. This is correct if you view the question as it relates to the BATFE definition in regards to storage and transportation. I’m not trying to argue, but to clarify that the correct/best answer depends on the context.
Nick has given you very good and accurate information.
My take on it is that there is no similarity. One is an explosive, the other a combustible plastic(smokeless) that has both oxidant and fuel combined at the most intimate level possible, with other components meant to increase or decrease rate of burn or change the stored energy (nitroglycerin).
They are both made of the same active ingredients. Nitro glycerin and gun cotton, which iirc, is defined as a low grade explosive. If compounded one way or used separately, they act as an explosive, creating both a shock wave and releasing hot gasses, for all practical purposes, instantaneously. If treated with retardants and other chemicals, they are merely fast burning products that are designed to burn and release hot gasses at a rate that will function to propel bullets.
Imo, in a very simple way of speaking, there is no functional similarity. The function differently and perform differently and don't remotely have the same purposes.
My take on it is that there is no similarity. One is an explosive, the other a combustible plastic(smokeless) that has both oxidant and fuel combined at the most intimate level possible, with other components meant to increase or decrease rate of burn or change the stored energy (nitroglycerin).
They are both made of the same active ingredients. Nitro glycerin and gun cotton, which iirc, is defined as a low grade explosive. If compounded one way or used separately, they act as an explosive, creating both a shock wave and releasing hot gasses, for all practical purposes, instantaneously. If treated with retardants and other chemicals, they are merely fast burning products that are designed to burn and release hot gasses at a rate that will function to propel bullets.
Imo, in a very simple way of speaking, there is no functional similarity. The function differently and perform differently and don't remotely have the same purposes.
Lots of good info here
Thanks guys for giving me all the detailed info on my original post.
One last thing - Would I be close in saying that Gunpowder is like a line of Dominos, standing on edge. You flick one Domino and they all fall down one after the other.
An Explosive is like having a line of Domino's standing on edge and you pound the table top with your fist and ALL the Dominos fall at once.
I'm trying to come up with simple explanation and visualization to compare Gunpowder vs Explosion.
Is this OK or what do you suggest?
Thanks JD
Thanks guys for giving me all the detailed info on my original post.
One last thing - Would I be close in saying that Gunpowder is like a line of Dominos, standing on edge. You flick one Domino and they all fall down one after the other.
An Explosive is like having a line of Domino's standing on edge and you pound the table top with your fist and ALL the Dominos fall at once.
I'm trying to come up with simple explanation and visualization to compare Gunpowder vs Explosion.
Is this OK or what do you suggest?
Thanks JD
ShootistPRS
New member
With all the different burn rates of modern explosives a better way to make the definition thusly; Explosives burn at the same rate in the open as they do when contained while propellants burn faster with more pressure.
Place a half pound of black powder in a pile and a yard away place a half pound of smokeless powder in a pile. Touch a match (make it a very long match) to each and compare the results. The black powder will blow up and the smokeless powder will burn for a long time. Black powder is the slowest explosive that I know of but still very useful.
Place a half pound of black powder in a pile and a yard away place a half pound of smokeless powder in a pile. Touch a match (make it a very long match) to each and compare the results. The black powder will blow up and the smokeless powder will burn for a long time. Black powder is the slowest explosive that I know of but still very useful.
Yes, somewhat like a domino, in that it progressively lit by the previously ignited piece, and it burns progressively, just like the domino takes a tiny amount of time to fall, and as it falls, it tips the next, and still expends a little more energy afterwards. A very good analogy, I guess. A very rapid chain reaction.
An explosive isn't at all like that. The chain reaction isn't really a chain reaction at all, so to speak, that wave front goes screaming through the explosive detonating as it goes, and it is pretty much over as the wave passes.
I kind of think that an explosive works more like a line of dominos that is whacked with a baseball bat.
An explosive isn't at all like that. The chain reaction isn't really a chain reaction at all, so to speak, that wave front goes screaming through the explosive detonating as it goes, and it is pretty much over as the wave passes.
I kind of think that an explosive works more like a line of dominos that is whacked with a baseball bat.
If you light C4 on fire, it burns. If you stomp on the burning C4, it will explode.
Smokeless powder can be made to detonate, in an unconfined area, if you provide a big enough starter push (as demonstrated in a research project by the ATF when they were looking to more heavily regulate the smokeless powder rules). However it is much more difficult to do than with something like C4 or TNT, and since the commercial blasting caps necessary to get smokeless powder to explode are already a controlled item, it doesn't make sense to treat the smokeless powder as a more heavily controlled item.
Chemically or technically, smokeless powder is an explosive material, nitrocellulose. Legally, I'm glad that it isn't classified as such because it makes reloading a much easier hobby to engage in.
Jimro
Smokeless powder can be made to detonate, in an unconfined area, if you provide a big enough starter push (as demonstrated in a research project by the ATF when they were looking to more heavily regulate the smokeless powder rules). However it is much more difficult to do than with something like C4 or TNT, and since the commercial blasting caps necessary to get smokeless powder to explode are already a controlled item, it doesn't make sense to treat the smokeless powder as a more heavily controlled item.
Chemically or technically, smokeless powder is an explosive material, nitrocellulose. Legally, I'm glad that it isn't classified as such because it makes reloading a much easier hobby to engage in.
Jimro