BP Hoarding

[BarryE]

Guys, I thoroughly understand the need to stock up given the conditions.  Please store it as safely as possible.  10 pounds of powder exploding in a fire would cause tremendous damage.  You, your family, your neighbors, and your firefighters could have a very bad day.

[Daryl]

You would think so, BarryE. Sometimes what happens isn't like we think it would be.  A close friend of ours had his house trailer "go up" completely, yet he powder did little - the 25 pound bags in cardboard boxes "whooshed", and very few of the cans in the 25 pound box ignited, just splitting the seams. Most of the cans only had charred sides.
He was at rendezvous when this happened and the local (Kamloops, B.C.) "mounties" found him in the Camp. Sad day indeed, he did lose some nice flinters in the fire.
Local kids lit a fire in a shed behind his trailer - playing with matches, lighting fires or smoking, who knows? The fire went through the dry grass to ignite his trailer and others close by.
What was dangerous, was the 2, 20 pound empty propane bottles in the trailer. They blew the roof off & went "boom".

[BarryE]

Unconfined black powder may have whooshed.  Confine it and it becomes a bomb.  As I'm sure you know, black powder detonates, not deflagrates (rapid burning) like smokeless.  The force of the explosion is relative to what it is in.  My post was relative to storing large amounts of black powder in a safe manner.  Away from heat, sparks, static electricity and anything that may cause it to otherwise detonate. If a firefighter (or anyone else) had been in the near proximity to the 25 pound box when it went off, it would still not have been very good. (You'll have to pardon me. 40+ years as a firefighter and fire investigator makes me think of this stuff!  And yes, propane cylinders are nasty!)

[Mad Monk]

Unconfined black powder may have whooshed.  Confine it and it becomes a bomb.  As I'm sure you know, black powder detonates, not deflagrates (rapid burning) like smokeless.  The force of the explosion is relative to what it is in.  My post was relative to storing large amounts of black powder in a safe manner.  Away from heat, sparks, static electricity and anything that may cause it to otherwise detonate. If a firefighter (or anyone else) had been in the near proximity to the 25 pound box when it went off, it would still not have been very good. (You'll have to pardon me. 40+ years as a firefighter and fire investigator makes me think of this stuff!  And yes, propane cylinders are nasty!)

Barry,

Black powder does not detonate.  It is physically incapable of detonation.  It is strictly surface burning.  What controls how fast it will surface burn is how much heat is lost when it first starts to burn.  And old du Pont's Blasters Handbook stated that open trains of black powder measured in feet per second.  You can see the powder slowly burning down an open train of powder.  But once you confine it as in the old lead tube burn rate test you can see flamepreading rates down through at tube at up to 2200 feet per second.

The difference in this open versus closed burning involves the use of potassium nitrate as the source of oxygen.  You must first heat the potassium nitrate to its melting temperature where it turns into a liquid.  Then you must add more heat to get it up to to decomposition temperature where it will release oxygen to produce additional burning.  When the grains of black powder burn the surfaces of the grains turn to a film of liquid that then releases oxygen.  The actual combustion of the three ingredients actually occurs in the gases above the surfaces of the grains.

Aberdeen Proving Ground used to mold sticks of black powder that had a coating on the sides of the cylinders that prevent the flamepread from going down the sides of the cylinder of powder.  Then they would take high speed movies of how that top surface of the stick turned to a liquid and pushed combustible ingredients, charcoal and sulfur up into the burning zone a short distance over the top of the stick.

When the NMLRA talked GOEX into shipping 25 pound boxes of black powder by a common carrier variance the tests involved sticking a detonator in one open can among 24 unopened cans in the case.  The other cans did not go up in a sympathy explosion.   This was again looked at when the different black powder companies switched to plastic bottles away from what became very expensive tin cans.  The blow molded plastic bottles have two mold seams running the length of the bottle.  When ignited invariably the bottle seams would start to split open.  That prevented having enough pressure in the case to destroy the other bottles.   And if you heat the powder slowly you get no fire and no explosion if the powder is not tightly confined.  The powder will start to give up the sulfur when the powder is heated to around 180F.  If the sulfur can drift away from the powder in the air the powder simply goes dead.  You see what looks like the grains boiling when the potassium nitrate melts and releases oxygen.  That 10 parts of sulfur in the powder is really the thing that gets the powder burning.  As soon as the sulfur melts and turns to a vapor it becomes rather active.  Once in a vapor form the sulfur itself you go up in flames fairly fast.

Back in the days of multi-engine propellar driven aircraft they used black powder made without sulfur as a gas generator to push  fire suppressing chemicals out into the engine nacelles to put out engine fires in flight. You see that same sulfurless black powder used in starter cartridges for single engine fighter aircraft in WWII.     

[smylee grouch]

Thanks Bill for that run down on the sequence of events when the powder is ignited and burned in an open fashion.  I wonder if sometimes          Hollywood and the anti-news media  has it wrong.

[Mad Monk]

Thanks Bill for that run down on the sequence of events when the powder is ignited and burned in an open fashion.  I wonder if sometimes          Hollywood and the anti-news media  has it wrong.

Well Hollywood and the news media want to paint this picture where black powder is so nasty and untrustable.  It adds danger and excitement to there story line.  When I looked at all of the different versions of black powder that was produced I had to look outside the gun use and was amazed at how versatile it is in how you can modify it for different behavior for a wide range of uses.  Actually part of the reason it has been around so long after other propellant and explosives were developed. A lot of the newer propellants and explosive compositions have rather narrow use applications.  You can alter black powders over a wide range of applications. 

[bones92]

Bill (Mad Monk)... thank you for the very informative input.   It kind of makes one wonder what other untapped applications there are for black powder.

[BarryE]

My bad, BP is considered a low explosive and does deflagrate not detonate.  None the less close proximity to that deflagration with large amounts of powder is still a potential hazard.  I’ll repeat, I simply want everyone to use care when storing large volumes of powder.

[Mad Monk]

My bad, BP is considered a low explosive and does deflagrate not detonate.  None the less close proximity to that deflagration with large amounts of powder is still a potential hazard.  I’ll repeat, I simply want everyone to use care when storing large volumes of powder.

Barry, 

I should have done a better job of explaining my thinking.  There have been instances of large quantities of black powder stored in magazines going up in what would be described as a mass deflageration.  There was a good Bureau Of Mines involving one such incident.  All of the powder in the magazine had a fairly high moisture content.  They described the powder as "wet".  This started a chemical reaction between the sulfur and the potassium nitrate in the powder that released heat.  So the temperature of the whole mass of powder was going up.  Confined as it was in the magazine it could not cool or dissipate the heat.  So the whole mass just auto-ignited at the same time.  In effect it mimicked true detonation.  Left a real big hole in the ground.

Going back into the 1800s and the experiments to replace black powder as a gun propellant.  Early trials with the then new nitrocellulose was full of gun failures. Then they modified the nitrocellulose which killed the ability of that to detonate.  That started a hard and fast rule of thumb.  That being if there was even a one in one million chance of a charge of propellant powder detonating then it simply could not be used as a propellant in firearms.  It has been estimated that for the year 2021 the civilian shooters in the U.S. will purchase 12 billion cartridges for guns.  That comes out to about 36 million cartridges per day.  So if there was a one in one million chance of powder charge detonation you would see mass destruction in the gun and badly injured or dead shooters.  Like  maybe 36 a day based on the chances here.  Then figure that out to 365 days a year.   So that one chance in one million of a detonation gun blow up would really add up in injured or killed shooters.   Now in my industrial background my job position was about 500 feet from a tank farm in which was stored up to 8 million pounds of vinyl chloride monomer in tanks with several tank farm operators heavy into smoking weed on their breaks.  So a case of black powder was not on my most feared list.

[BarryE]

Thanks for your reply.  Methyl Ethyl Badstuff is always a concern in my field.  But most people and firefighters are harmed by everyday stuff in homes, usually when someone does not take the time to consider what they are doing.  A bit of thought is usually a good thing here.  Let us conclude that we all love BP and no one should fear it. Just use a bit of education and some common sense and let the smoke roll!

[Ric Carter]

 I've been buying by the case for over 30 years. I don't consider myself a hoarder, I just like paying less for powder.

[One Shot]

I have been buying by the case for many years for my MLs and ss BLs. Never considered it hoarding just on hand for use. Still hope to get my order of OE and Swiss that I placed in June right before the fire. Oh well. Something will be available soon I trust.

[Bob Roller]

You would think so, BarryE. Sometimes what happens isn't like we think it would be.  A close friend of ours had his house trailer "go up" completely, yet he powder did little - the 25 pound bags in cardboard boxes "whooshed", and very few of the cans in the 25 pound box ignited, just splitting the seams. Most of the cans only had charred sides.
He was at rendezvous when this happened and the local (Kamloops, B.C.) "mounties" found him in the Camp. Sad day indeed, he did lose some nice flinters in the fire.
Local kids lit a fire in a shed behind his trailer - playing with matches, lighting fires or smoking, who knows? The fire went through the dry grass to ignite his trailer and others close by.
What was dangerous, was the 2, 20 pound empty propane bottles in the trailer. They blew the roof off & went "boom".

Yesterday in this area there was a propane explosion in a home that reduced it to kindling wood and several people badly burned PLUS the home next to it was a total loss as well. My current stash of 12 pounds of assorted black powder in on my little machine shop so if the house burns there will be no "Whoosh or Kaboom".
Bob Roller

[bob in the woods]

There is a good reason to buy large quantities of BP which is seldom discussed by a lot of shooters, however, if you are involved with long range shooting, you would be wise to pay attention to lot # s
When participating in 1000 yard matches, I have noticed changes in impact locations between different lot # s of powder, necessitating sight adjustments.

[Hungry Horse]

 An old friends house caught fire and burned nearly to the ground. My friend wasn’t at home, and the fire department cooled the ashes, and what little was left of the house. My friend got there just as the firefighters were leaving, and asked them if there had been an explosion. They said the only explosion they witnessed was the hot water heater. He went to where his man cave had been, and dug around in the rubble, and found the corner of his shooting box. When he pulled it out of the rubble the other end of it was burned off. He opened it and found his powder horn, and priming horn set smoked almost black, and two pounds of powder in cans with all the painted labels burned off. We rubbed the horns back to a nice antique brown and he kept using them. So, I’d say black powder can take a lot of heat, as long as it didn’t get touched by a spark.

  Hungry Horse

[Mad Monk]

There is a good reason to buy large quantities of BP which is seldom discussed by a lot of shooters, however, if you are involved with long range shooting, you would be wise to pay attention to lot # s
When participating in 1000 yard matches, I have noticed changes in impact locations between different lot # s of powder, necessitating sight adjustments.

Bob,

That lot to lot variation in burn rates and ballistics strength is not uncommon in modern black powder.  If you go back to du Pont at the Brandywine works they would take roughly 8 lots of a powder and cut them in half.  Then start blending back together where all 8 lots become one lot with the same burn rate and ballistic strength.  The Brits and the Germans worked it the same way.  This was considered to be very important to the early commercial cartridge loading companies so that there would be little lot to lot difference in their cartridge production.

When I as closely following GOEX Moosic production I was looking at that and recording all of the code info off the bottom of the can.  When these various BP manufacturers got away from preparing their own charcoal this lot to lot variation thing became really noticeable.  Moosic was using a charcoal purchased from a company in Ohio who ran one wood charring operation in West Virgina.  They cut and charred maple wood.  Did not remove bark before charring.  The bark being a major source of minerals found in the finished charcoal.  The minerals being shown as ash content.  I looked at a number of lots of charcoal put out by that company.  Ash content varied from 5% to 15% by weight in the charcoal.  And there was no compensation correction used in the final weights of the ingredients going into the wheel mill.   Then there was some lot to lot variation in the purity of the potassium nitrate purchased to make the powder.  That altered the amount of oxygen available to the combustion process when you shot the powder.   When GOEX moved to Minden they had lost the Ohio charcoal source and had to search for one suitable.  I had a lot of 3F packaged one day and another lot packaged the following day and had the second lot fall 100Fps in muzzle velocity out of my .50 caliber round ball test rifle.
Then they did not have a good accurate way of controlling the actual charring of the wood.  So there were lot to lot differences in the fixed carbon content of the charcoal and that plays a major role in powder combustion rates and strengths.

I was dealing with a local who shot competition ml.  I filled him in on this.  So he would pick two or three different lots of bp out of what Chuck Dixon was selling. If he found a fairly good lot he would go to a distributor and order a case or two of that particular lot.  Saved him a bunch of trouble and work in having to work up new loads to his accuracy standards.

[davec2]

Mad Monk,

When I was a kid I experimented with a propellant powder that I made with just ammonium nitrate and charcoal.  I loaded several metallic cartridges with it and it seemed to work OK.  I only used small quantities and I just loaded the powder as a meal....I didn't try to corn / granulate it like black powder.  Was this type of powder ever used for gun propellant or blasting ?

[Mad Monk]

Mad Monk,

When I was a kid I experimented with a propellant powder that I made with just ammonium nitrate and charcoal.  I loaded several metallic cartridges with it and it seemed to work OK.  I only used small quantities and I just loaded the powder as a meal....I didn't try to corn / granulate it like black powder.  Was this type of powder ever used for gun propellant or blasting ?

Dave,

As far as I know ammonium nitrate has never been used in a propellant powder for lack powder guns or smokeless.  Ammonium nitrate is a low order detonating compound.  As such it is considered to be too dangerous.  If a propellant powder has even a one in a million chance of exhibiting that low order detonation it cannot be used for safety reasons.  At first the idea of a one in a million chance was strange.  But then I saw just how many cartridges are used in the U.S. in one year.  That 1 in a million chance of low order detonation would involve 36 guns a day at that rate.

An old du Pont Blasters' Handbook had a statement that has stuck in my mind a lot of years.  There was a short discussion of the use of sodium nitrate in cheap blasting powders but potassium nitrate was still used in gunpowders where "uniformity of action" is critical.  That uniformity of action was their way of describing uniform shot to shot pressure development profiles in the gun.  We look at this uniformity of action almost strictly from uniform muzzle velocities.  But you can still not a non uniform action within the gases that are pushing the projectile up the bore.  One described it thusly.  If the ignition and combustion of the powder charge is not uniform in behavior it is as you you are pounding the projectile up the bore with a hammer.  I once had some pressure bomb graphs of a number of samples of black powder out of Aberdeen Proving Grounds thanks to a buddy who worked there.  The pressure curve showed blips where there were very rapid pressure changes in the gases.

I don't know about the ammonia in the ammonium nitrate.  Ammonia in the form of a gas will leach copper out of brass very quickly.  So I don't know if as the ammonium nitrate ages does it release any traces of ammonia.   This thing about brass and ammonia is why we saw a lot of ammonia used in brass cartridge rifle cleaners.  It would quickly remove copper films from the rifle bore.

[Mad Monk]

Dave,

To expand a bit more on the "uniformity of action" point.
Back in the 1980s I as haunting gun shows looking for original black powder cartridges.  Picked up a single Eley-Kynoch .295 Rook cartridge made in Austria in the late 1800s.   Pulled the bullet to get to the powder.  And it was not a full case load and the powder grains were large, about 1F in size, and bright red, not black.  Took the powder apart.  Bright brick red charcoal.  when I ran that red charcoal through the Coulter Counter to look at particle size I was shocked.  At least 30% of the charcoal had been ground to a particle size of less than 1 micron.  With a normal sporting powder black powder you might see a few percent of the charcoal down around that micron particle size.    But this "toasted" versus charred glossy buckthorn alder charcoal was so soft it was easy to grind that small.  With a very wild burn rate which is why the grains were close to 1f in size.

Now Ely advertised on their boxes of these rounds that the maximum velocity spread in a box of 20 was 5 feet per second over the chronograph.  Then after showing what I saw in mine to a well known bp cartridge shooter out West he picked up a full box at a gun show.  His old rifle collection contained a British .295 Rook rifle.  He shot the box over the chronograph and found Eley's advertising claim to be accurate.  And they used a 99.9% pure potassium nitrate in their powders.

A lot of those .295 Rook rifles ended up in Australia used to hunt kangaroos.

[davec2]

Mad Monk,

I did some poking around.....I couldn't figure out where I got the idea to try the ammonium nitrate / charcoal propellant mixture.  I did this 50 years ago..... long before the internet...so   And then I found my copy of "The Chemistry of Powders and Explosives" by Davis.  There is was.......





From other information I have, it was apparently used in both small arms and artillery until superceeded by modern smokeless powders.

[Daryl]

That was an interesting read, Dave.  The sentence about the crystallizing and crumbling if the temp is raised over 32.1 degrees, increasing burning and destruction of the gun,
kinda spooked me.

[Mad Monk]

Dave,

The Davis book on the ammonpulver leaves out a good bit of that story.  I never saw anything indicating any use here in the U.S..  Military or civilian.  Germany and Austria used it as an artillery propellant.  When loaded into brass cases it will destroy those cases in a few months. Can literally dissolve the brass.  Also if shot in a rifle the whole rifle must be washed after the shooting session with hot water. The ammonium nitrate from powder combustion will damage metal and wood.  Considered very corrosive.

As Europe geared up for WWI the Germans and the Austrians were in a panic.  They could not get potassium nitrate in any quantities for artillery use.  The only really major supplier of potassium nitrate in the world was India that exported millions of pounds a year of potassium nitrate.  And England controlled exports out of India.  Which put Germany and Austria on the short supply list.  Just prior to WWI the military powers were working with changing to stronger steels to deal with the developing nitrocellulose powders.  This ammonpulver simply filled in a gap between the end of the black powders for artillery and the introduction of smokeless powder that would be safe in artillery.   But here in the U.S. there was no total lack of potassium nitrate.  Tight supplies at times but no total loss of supplies.  Then here in the U.S. you see a host of powder makers plying with nitrated saw dust as a modifier in black powder mixtures.

[Daryl]

Semi-smokeless and Kings Semi-smokeless which might have been the same powder
loaded bulk, same as BP.
In England as well, in the late 1890's.