Explosive vs Gunpowder

[C7AR15]

What is the difference betwen an explosive and gunpowder?

The way I understand it, is that a exposive has an instantaneous release of energy while gunpowder merely burns.

Can anyonefill in with more information

[T. O'Heir]

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.

[mete]

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.

[std7mag]

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...

[FITASC]

Gunpowder is listed, and considered to be, a flammable solid, not an explosive

[C7AR15]

I think that sums up the difference between the two.

Instant transition to gas , without burning.

[Unclenick]

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.

[243winxb]

Unclenick has covered it well, as always. http://www.firearmsid.com/Feature%20...ord_gunpowder/ Interesting read.

[hdbiker]

explosives are exactly that, explosives, gunpowder on the other hand is a propellant. hdbiker

[reddog81]

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.

[JeepHammer]

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.

[ShootistPRS]

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.

[willr]

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

[Unclenick]

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.

[reddog81]

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.

[briandg]

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.

[C7AR15]

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]

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.

[briandg]

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.

[Jimro]

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

[JeepHammer]

Jimro,
Now you are getting into an area I'm intimately familiar... 16 years worth.

That C-4 will explode while burning is a myth, tried it many times.
I understand that early C-2 could be detonated while burning,
But C-3 & C-4 require MUCH higher compression rates to detonate than a human can produce.

I've seen tracer bullets pass through C-4 many times.
(Yes, bored Marines will shoot at C-4)
C-3 & C-4 was specifically designed to go into combat,
While stuff like RDX & PTEN won't take rifle rounds very well.

Mix RDX & PTEN (and a couple other things) and you come up with 'Home Brew' Simtex, a favorite of our suscide vest wearing 'Friends' in the sandbox.
They USED to go with plain old C-3 or C-4, but you could shoot through without detonation to stop the idiot,
With the home cooked simtex, you have to have a headshot or risk detonation.

The stuff a farm kid learns when he sets out to 'See the world'...

[briandg]

The easiest way to consider the question is to accept that under normal circumstances, with ordinary quantities, used properly, smokeless is not a high level explosive. It has been around for over a century, and for most of that time it wasn't scientifically proven to be possible.

For shipping,It's regulated as division 1.3 explosive and referenced as not having a mass explosion hazard. It is regulated with professional grade fireworks and rocket fuel. 1.4 is consumer grade fireworks and ammunition, black powder is 1.1, they differ in sensitivity and capacity for a "blast" or "explosion".

Class 1.1 includes black powder and nitroglycerin, presenting a "mass explosion hazard".

Class 1.3 includes smokeless and it is a "minor blast hazard".

Class1.5 includes unaltered ANFO.

Way back before regulations were strict, a story goes that many, many tons of smokeless was contained in a magazine at a plant surrounded by a berm, and it was accidentally set off. The berm wasn't damaged, the building remained mostly intact, there were no injuries as the area was unoccupied, but it created a flare and flame that could probably have been seen from jupiter.

So by classification it is called an explosive, it's regulated as a blast hazard, but not an explosion hazard. Although it is compounded with high explosives, just like dynamite is, inhibitors and stabilizers change those characteristics. Dynamite is ng mixed with essentially dirt and that prevents the ng from igniting with shock or flame, it shouldn't detonate unless an extreme shock sets up the proper conditions. Powder is compounded with other chemicals meant to prevent the ng from igniting in a chain reaction that results in an explosion.

The way I see it is that it is, by definition and legal definition, an explosive, a class 1 substance. It is not a class 1.1, the highest level, it is considered a class 1.3, which does not cause an "explosion".

Think about it this way. The high explosive compounds in smokeless is in isolation, with buffers in between the molecules and powder grains. Even though fireworks are clearly made out of class 1.1 products, these products are buffered by packaging and other inert products. They are capable of a chain reaction blast, but not an "explosion".

[Jimro]

JeepHammer,

Shooting C4 won't detonate it until you shoot with something like a Raufoss API round from a Barret, where the disintegrating zircon ring provides it's own little explosion providing both heat and pressure to start the detonation sequence. Sometimes when you try to start C4 with detcord the detcord explodes so fast it can "cut" the C4 before it detonates, and you find chunks of C4 all over the demolition range...

Burn it on hard concrete, and drop an anvil on it, odds are you'll get enough to detonate. I'd say a Marine's boot probably wouldn't do it, probably need a Sailor, of at least Senior Petty Officer rank to get enough mass (I kid, I kid).

But the point is the same, you can get it to blow up with a commercial/mil grade blasting cap, as it can both deflagrate and detonate. Some explosive just don't deflagrate like Lead Azide or black powder and only detonate.

Jimro

[kraigwy]

Explosive is a relative term. Its nothing more then burning, but at a faster rate.

For example a low explosive would be somewhere near 14-16000 fps, where as a high explosive it closer to 26-27000 fps.

(Those are not hard and fast numbers, just thrown out there for references)

Meaning, Rate of Burn.

Basically there are two types of gun powder. Double based and single based.

Double bases contains Nitroglycerin and Nitrocellulose. Single based is Nitrocellulose. The size of the powder pieces and additives determine the burning rate.

Both are considered explosives, However you control the rate of burn, they are used as repellents.

Burning rates are regulated by heat and concussion. You just add head to the explosive, you get a slow burn. You add concussion with that heat you get an dentation (much faster rate of burn or explosion.

You can light C-4 on fire and cook you C-Rats, but you strike that burning stick of C-4 you get a much faster rate of burn, or an explosion.

Same with gun powder. Both Nitroglycerin and Nitrocellulose are explosives, but you control or restrict the rate of burn its a propellant.

With C-4 (and other explosives) you can burn it, or you can set if off with a blasting cap and it will explode (or burn super fast).

Same with smokeless gun powder, you can light a match to it and it will burn, You stick a blasting cap to it, it will explode (or burn super fast). It then becomes an explosive instead of a repellent, which is nothing more then a much faster rate of burn.

Depend on the make up of gun powder, (additives to control the rate of burn) you may need a stronger blasting cap, or a buster, but it will explode.

Basically repellents and explosives are nothing more then a difference of rate of burn. You control the rate of burn you can convert an explosive to a repellent to an explosive or visa versa.

[Unclenick]

Basically repellents and explosives are nothing more then a difference of rate of burn.

I'll be much more careful how I handle Deep Woods Off and Cutter's in the future.

That and the earlier comment by ShootistPRS separate detonation and confined explosive deflagration from open air deflagration, but not explosives from things that cannot explode. Exploding or deflagrating are both forms of combustion (burning), just different mechanisms. The former causes energy release by heat transfer and the latter by kinetic pressure wave. The former travels at the rate of heat transfer and flame spread, while the latter travels at the speed of sound in the explosive material or a bit faster due to compression. But as already remarked by several of us, many high explosives can either deflagrate or detonate depending on the source of ignition energy.

PETN (pentaerythritol tetranitrate) has been used as the igniter in incendiary rounds. So it can withstand acceleration in a gun barrel but not impact with anything very hard without going off. It is also the ignition charge used in the old standard powder burn rate test.