Development of types of gunpowder

[dale2242]

After 50 years of reloading, I am reading a 1972 printing of Maj. George C. Nonte, Jr.s Modern Handloading.
We sometimes need to go back to the basics.
Chapter 6 is about the manufacture of smokeless powder. It`s a very interesting read.....dale

[BattleRife]

Then there is 'gun cotton' which I read was too fast so it was mixed with black powder.

Gun cotton is essentially the rawest form of nitrocellulose. A semi-technical description so we are all on the same page:

A hydrocarbon is a class of molecule formed when carbon atoms link together in chains, with all the unused bonding sites on the sides of each carbon atom filled with hydrogen atoms. Carbohydrates follow the same basic structure.

Cellulose is a starchy hydrocarbon that forms the walls of plant cells. Cellulose gives the cell (and thus, the plant) strength. The cells of trees are very high in cellulose, which is why wood is very strong for plant matter, but the plant with the highest cellulose content is cotton. Cotton is over 90% cellulose by mass.

Nitrocellulose is formed by letting very concentrated sulphuric and nitric acids contact cellulose. The reaction was discovered by accident when a chemist cleaned up an acid spill with a cotton towel. The essence of the reaction is that some of the hydrogen atoms on the side of the carbons are stripped off and replaced with nitrate groups. Nitrate groups are very high in oxygen and provide that oxygen for combustion, eliminating the need for outside air and greatly speeding combustion by removing transport of reactants as a rate limiting step.

Since cotton is so high in cellulose, when the time came to make nitrocellulose intentionally cotton was an obvious choice. If you immerse cotton in the acid, then rinse and dry it, the cotton looks the same, but it is now a low explosive. This is guncotton, and was never a serious contender as a propellant, as the burn rate is obviously too high.

Once the cotton is nitrated, the usual step is to purify the nitrocellulose by dissolving it out of the cotton, filtering the leftover cotton solids out, then distilling off the solvent to leave pure nitrocellulose paste. Which obviously still burns much too fast to be a propellant. At this point other chemicals can be added to slow combustion and the pasty mixture can be extruded into shapes intended to slow the burn rate as much as possible.

In areas where cotton doesn't grow, like northern Europe, wood pulp is most often used as the source of cellulose.

[felix]

Perfect!

Mixing other chemicals (off-the-wall) using practical experiments is where it is today. Obviously still looking for realistic discoveries of which chemicals (out of a cast of thousands nowadays) to use which smooth projectile acceleration curves ("progressive" burn to the hilt) in all kinds of weather. ... felix

[Mal Paso]

I enjoyed organic.

Remember that smokeless powder is made of nitrated organic compounds.

There are schools that have degrees in explosive technology, not sure if that applies or not. Sometimes it is a case of getting a similar degree with the right basic knowledge and then getting a foot in the door.

Geeze! It'll never certify Organic once you douse it with chemicals.

Nitrocellulose is a propellant, not an explosive like black powder.

Nitrocellulose was also the film stock for the old B&W Movies and why old film fires are scary. Running Nitrocellulose film through an arc lamp projector seems like a fools errand but that's show biz.

Nitroglycerin is often added for energy buy does not make smokeless powder explosive.

[felix]

It is nothing but definition of words, i.e., formal chemistry or colloquial English. For example, an explosion can mean to normal folks as a rapid expansion (and/or contraction) of something before the blink of the eye. For others, the word detonation would be synonymous to an explosion/implosion. Same problem with the word organic. To me as a street person, something organic would be something that could be eaten by some kind of animal as fuel/food. Dogs eat poop, so let's don't go there. ... felix

[303Guy]

I've just had a look at Wikipedia. That's an interesting read. I also looked at Encyclopaedia Britannica which has pretty much the same information but one has to sign up for a free trial. I now know about triple based powders used in cannon. I now also know what the hollow powder kernels are for - they progressively increase the burn rate to compensate for the progressive decrease in burn rate as the kernels become smaller.

Nitrocellulose is an explosive as is nitroglycerine but not in the form of propellants in which they burn.

The whole history of smokeless powder development (including powder factory blow-ups) is in there.

http://en.wikipedia.org/wiki/Smokele..._and_guncotton

[btroj]

Yep, powder only burns on the surface of the granule. A solid stick has a shrinking surface area as it burns. Adding a hole thru the middle means the interior surface is growing as it burns to offset the shrinking exterior surface.

I am no expert here but I think the difference between propellant and explosive is as much a legal term as it is anything scientific. I view the difference as being a matter of shock wave propagation. Anything that produces a significant shockwave is explosive, things that develop pressure without much shockwave are propellants.

That is grossly oversimplified but it works for me.

[Mal Paso]

Smokeless powder doesn't go bang unless you confine it. Even a light 38 load is thousands of pounds.

Everything I've seen labeled Explosive goes bang confined or not.

You can create an explosion with smokeless powder but to my mind it is not an explosive.

[Mal Paso]

Isn't Detonation an Explosion caused by Concussion?

[SWANEEDB]

I have a book on "Early American Explosives", book is a reprint I believe from 1927, is about 2 inches thick, one powder company which I tried to find out more than what was printed about is the "California Powder Works", was located in the hills just north of Santa Cruz, (Is now called Paridise Park), is owned by the Masonic lodge, Cal P works located there because of the vast eqcaliptas trees. I was there in the mid 80's, the only way you could get in the park was to be invited by a member, tite group those masons, I was invited there to attend an annual lunchen which I still have the place mat, also while there I met a postman who had letter heads, envelopes and union papers (yes they were unionized), he made copies of the paper and sent them to me, still got them too. Another reason of their location was the S C harbor, used horse and buggies to transport black powder for shipping which was done mostly by Chinese labor, I had a few items that I donated to their museum which they did not have. If my memory serves me correctly they also made some of the first smokless powder used in the 30-40 Krag for that early war (?).
Amazing how many lives were lost in the early explosives industries.If anyone has an interest in this book i'll get the authors name and publishers of the book, it is full of history. When I lived in Cal I found a full box of 10ga shotshells,Made by the California Powder Works, name on it was 'YOSEMITY', only one other box had been located and it was in terrible shape, a high end shotshell box collector just had to have it, I sold it for a pretty good some.
OK, Woof woof Gus wants to go pee.

[SWANEEDB]

Isn't Detonation an Explosion caused by Concussion?

NO, I think fire, maybe wrong.

[btroj]

Some explosives require a concussion of some sort to set them off. This is why blasting caps exist. Some, like black powder, can be set off with a flame or spark.

[Dale in Louisiana]

I't a great resource if you can find a copy. Lists a lot of powders that came and went, or were replaced by superior powders. Some of the earlier powders were unstable and deteriorated rather quickly.

It's neat to see the original release dates of some of the current powders.

Shiloh

Regarding the Philip B. Sharpe book, I got a hard copy from Alibris. Search by title or author, pick how much you want to pay. Or find the on-line copy.

dale in Louisiana

[mrcvs]

I have a book on "Early American Explosives", book is a reprint I believe from 1927, is about 2 inches thick, one powder company which I tried to find out more than what was printed about is the "California Powder Works", was located in the hills just north of Santa Cruz, (Is now called Paridise Park), is owned by the Masonic lodge, Cal P works located there because of the vast eqcaliptas trees. I was there in the mid 80's, the only way you could get in the park was to be invited by a member, tite group those masons, I was invited there to attend an annual lunchen which I still have the place mat, also while there I met a postman who had letter heads, envelopes and union papers (yes they were unionized), he made copies of the paper and sent them to me, still got them too. Another reason of their location was the S C harbor, used horse and buggies to transport black powder for shipping which was done mostly by Chinese labor, I had a few items that I donated to their museum which they did not have. If my memory serves me correctly they also made some of the first smokless powder used in the 30-40 Krag for that early war (?).
Amazing how many lives were lost in the early explosives industries.If anyone has an interest in this book i'll get the authors name and publishers of the book, it is full of history. When I lived in Cal I found a full box of 10ga shotshells,Made by the California Powder Works, name on it was 'YOSEMITY', only one other box had been located and it was in terrible shape, a high end shotshell box collector just had to have it, I sold it for a pretty good some.
OK, Woof woof Gus wants to go pee.

Yes, can you get the author's name and publisher? Thanks!

[303Guy]

I see it as an explosive detonates while a propellant burns. Detonation means the explosive burns at the speed of sound in that material. Nitrocellulose has a detonation velocity of 7,300 m/s (23,950 fps) and Nitroglycerine has a detonation velocity of 7,700 m/s (25,262 fps). That's the speed of the shockwave passing through the material. Black powder is a low explosive and deflagrates. "In deflagration, the decomposition of the explosive material is propagated by a flame front which moves slowly through the explosive material, in contrast to detonation. Deflagration is a characteristic of low explosive material."

I wasn't sure how black powder 'explodes' and so there it is. I did know it doesn't need confinement to explode but compacting it and confining it increases the explosion rate.

What we need in a rifle propellent is an energetic substance that disassociates at higher temperature which would limit the energy release rate so as to maintain pressure down the bore. Trouble is pressure raises the disassociation temperature (I think?) Disassociation is the when heat breaks the products of combustion down to it's constituents which then recombine as temperature falls.

[willk]

Going further in Wikipedia, they also had a pretty good article on Hercules, Inc. It includes dates of introduction of various smokeless powders

http://en.wikipedia.org/wiki/Hercules_Inc.

[olafhardt]

After I got my degree in chemical engineering I went to work as the supervisor of the quality control lab supervisor at an ordinance plant. It was not a safe job. In my career I have worked with explosives, really toxic gasses, acids, caustics, flamibles, superheated steam, high voltage and the list goes on. I rate explosives as the worst. I don't believe there is a safe way to manufacture explosives. I always thought people who say smokeless powder is not explosive were not playing with a full deck. There is a lot I don't know and you don't know and what you don't know can kill or maim you in the most horrible and sudden fashion. But I enjoyed my career and got through it alive although disabled by exposure to chemicals. I don't have hooks for hands, got to see my kids grow up and I only buy one pound of powder or 1000 primers at a time.