Is excess powder really blown out?

[zimmerstutzen]

Necchi, the problem is that as more powder is added, the distance gradually decreases to the muzzle. So what might be 28 inches of travel in a gun is reduced to perhaps 26 or even 25 inches to muzzle. A ball seated over 50 grains is not as close to the muzzle as one seated over 100 grains and not as close as a ball seated over 150 grains. There is less distance for the pressure to push the ball to velocity. In addition, does the extra powder at some point become part of the weight pushed with the ball? If the early Lyman pressure tests are considered, there are times when the pressure continues to climb close to proportionately, but the velocity does not. It is easy to find fault with the Lyman pressure tests, but I am not aware of any others.

 

[Black Hand]

No one bit on my question as to what exactly was meant by 'excess' powder, but it's pretty much the reason behind this long-running discussion about unburnt powder being blown out of the bore. In the 18th century and I don't know how much earlier, the belief was that for every barrel length there was an exactly perfect amount of powder in the charge. If the perfect charge was used for that length barrel, then the powder would be completely burned exactly when the ball reached the muzzle. Any less than that amount and all the powder would burn, but some power would be lost. More than the perfect charge and it could not all be burned in that length barrel, and so the 'excess' would be blown out and wasted.

Experiments and better understanding proved that idea to be incorrect, but it has hung on to the present day, maybe just to give us something to talk/argue about.

Spence

There might be a possibility that unburnt powder could be blown from the barrel IF there was no ball loaded.

 

[longcruise]

I was about to go for it, Spence but you checked your bait and pulled it away at the last second!

 

[zimmerstutzen]

No one bit on my question as to what exactly was meant by 'excess' powder, but it's pretty much the reason behind this long-running discussion about unburnt powder being blown out of the bore. In the 18th century and I don't know how much earlier, the belief was that for every barrel length there was an exactly perfect amount of powder in the charge. If the perfect charge was used for that length barrel, then the powder would be completely burned exactly when the ball reached the muzzle. Any less than that amount and all the powder would burn, but some power would be lost. More than the perfect charge and it could not all be burned in that length barrel, and so the 'excess' would be blown out and wasted.

Experiments and better understanding proved that idea to be incorrect, but it has hung on to the present day, maybe just to give us something to talk/argue about.

Spence

Stating that as an either or is probably fallacious. Powder is rarely all consumed within the barrel, but there is a point at which the velocity no longer climbs at the same rate as it had before. Is a portion of that additional powder still burning when the ball leaves the muzzle? of course. Does the muzzle flash get larger with even more powder. Sure seems so. Do velocity increases drop off because of a shorter travel to the muzzle, because the main charge is still burning, (i.e. has not yet imparted it's maximum push to the ball when it exits), or some combination of of these.

 

[George]

Paul V claimed to have gathered unburned powder and ignited it. I always took him with a grain of salt.

Bushel.

Spence

 

[Brokennock]

"Benjamin Robins, and the Royal Society" sounds like the name of a 1960s British Invasion band.

 

[Carbon 6]

For the ball to move faster, we'd have to set off a second pressure release behind to push it as it attains maximum velocity from the first pressure release.

Huh ?..

 

[necchi]

Experiments and better understanding proved that idea,,

Wow, post #60.
Thanks for the brain food, Lol and (bow icon)
It's been fun to think.

 

[necchi]

Huh ?..

Right, and we can't do that with BP in our rifles or cannon.
They (the world wide military suppliers) have made "huge" progress in weapons velocity in just the last few years.
Continued development has pushed the projectile (the ball/mass) to hyper-sonic speeds.
I digress, sorry,, we now return to our regular channel.

 

[Carbon 6]

Continued development has pushed the projectile (the ball/mass) to hyper-sonic speeds.
.

With black powder, in a muzzleloader ?
That would be in excess of 5600 feet per second.

Please document that .

 

[necchi]

oh lord,, sorry, "Modern development" has,,,
Gimme a break,,
Sorry if the "ball/mass" reference confused you.
The ball is a projectile,, modern 223 ammo as supplied to military is still referred to as ball ammo.

 

[Carbon 6]

oh lord,, sorry, "Modern development" has,,,
Gimme a break,,
Sorry if the "ball/mass" reference confused you.
The ball is a projectile,, modern 223 ammo as supplied to military is still referred to as ball ammo.

Phew ! What a relief. You had me worried I woke up in an alternate dimension.

 

[Britsmoothy]

Phew ! What a relief. You had me worried I woke up in an alternate dimension.

Yes, pararell universes. They do exist.

 

[Okie Hog]

In the October, 2007 National Rifleman magazine Bryce Towsley tested all the existing BP substitutes as well as Goex, Scheutzen and Swiss black powder. The velocity of the 100 grain charge of Swiss 2F powder was 1,879 fps. 150 grains of Swiss 2F gave only 2,065 fps. The flash from powder burning outside the barrel made obtaining an accurate chronograph reading very difficult.

 

[azmntman]

The presence of unburnt powder could be easily determined. Shoot over a sheet, collect the ejecta and try to set it a-light. Unburnt powder should flash and carbon won't really do too much...

I seem to recall Brownbear did just that and it did not ignite.

 

[Eterry]

Everytime the unburnt powder on snow comes up or someone talks about black powder "burning" I smile and shake my head .

Has anyone here ever lit a cap full of ffg on a concrete floor? We did, my friend lost most of his eye brows. It DOESN'T BURN, IT EXPLODES. I had plenty of smokeless powder, same experiment. IT BURNED.

We were Bored college kids on a rainy day, we burned a sample of rifle, pistol, shotgun, and black powder. The stuff we can't talk about here burned at very different rates, the black powder was gone in a whoosh.

If you think black powder burns... you've watched too many old movies.

PS: Years earlier I was at a friend's house, he had a cva derringer. He filled it FULL with 2ffg and crammed a ball on top, daring me to shoot it. No way, Jose. He finally did, it broke the stock and flew from his hands. His dad stopped our experiment, my dad stopped me from sitting down a few days. The fireball was impressive and Im pretty sure most/ all the powder exploded.

There are very few absolutes in life, but after wasting half a pound of ffg to experiments I find it hard to believe any can survive intact leaving a bp rifle.

 

[Black Hand]

Everytime the unburnt powder on snow comes up or someone talks about black powder "burning" I smile and shake my head .

Has anyone here ever lit a cap full of ffg on a concrete floor? We did, my friend lost most of his eye brows. It DOESN'T BURN, IT EXPLODES. I had plenty of smokeless powder, same experiment. IT BURNED.

We were Bored college kids on a rainy day, we burned a sample of rifle, pistol, shotgun, and black powder. The stuff we can't talk about here burned at very different rates, the black powder was gone in a whoosh.

If you think black powder burns... you've watched too many old movies.

PS: Years earlier I was at a friend's house, he had a cva derringer. He filled it FULL with 2ffg and crammed a ball on top, daring me to shoot it. No way, Jose. He finally did, it broke the stock and flew from his hands. His dad stopped our experiment, my dad stopped me from sitting down a few days. The fireball was impressive and Im pretty sure most/ all the powder exploded.

There are very few absolutes in life, but after wasting half a pound of ffg to experiments I find it hard to believe any can survive intact leaving a bp rifle.

Explosion vs. deflagration
https://www.thoughtco.com/explosions-deflagration-versus-detonation-607316
Deflagration depends on oxygen (donated by Potassium nitrate KNO3 in black powder), detonations do not.
http://guns.connect.fi/gow/nitro.html

 

[Artificer]

Is anyone aware of any scientific appraisal that has ever been done regarding this question?

Spence

Spence,

You may or may not remember four or so years ago that I posted a link that one of the first such example of a scientific test that was published, was done by the Royal Society of London in I think it was 1751 or 52. They took what must have been a pistol barrel and loaded a fairly stout charge, then the ball and there was only a small amount of barrel space left over the ball. They counted I think it was 12 unburned granules/specs/bits/EJECTA of powder and thus concluded (correctly) that every grain of powder that WOULD burn up, did so in the barrel.

Not every “grain” of blackpowder will ever burn up in a barrel and no matter how long the barrel is. This is due to the fact there must be sufficient oxygen for a complete burn and that oxygen comes from air surrounding the black powder in the charge before firing and the saltpeter in the mixture when the powder is burning. If there is not enough saltpeter near a grain that is mostly charcoal, it won’t burn up in the barrel. Actually, even the oxygen rich environment of the air after the unburned ejecta exits the muzzle is not enough to completely burn up the Ejecta that is mostly charcoal. That’s why one gets “grains” of Ejecta when fired over a tarp or snow.

I just did an extensive search going back to when I first joined the forum and could not find the link to the 1751 or 1752 test done by the Royal Society of London I wrote about above. However, I found an even earlier bit of documentation you originally provided to me and will quote that below:

“With GREAT appreciation to Spence (our Forum GURU and "E.F. Hutton" for period documentation) who provided a source and steered me to a chapter in W. Cleator's 1791 Essay on Shooting, I found an 18th century reference for spreading a cloth in front of a barrel to check for unburned powder.

"To determine this, a number of experiments were made by a committee of the Royal Society, so long ago as the year 1743 and by these it was shewn, that, when a barrel was shortened so much that the ball was placed before the powder was upon a level of the muzzle, the unfired powder, was collected from the discharge by means of a cloth spread before the piece, weighed but one twelfth the charge."

At the end of the paragraph:

And we may therefore safely conclude, that the powder is completely inflamed before the ball or shot arrives at the mouth of the shortest barrel ever employed.”


The Royal Society had it right as far back as 1743.

Gus

 

[zimmerstutzen]

And we may therefore safely conclude, that the powder is completely inflamed before the ball or shot arrives at the mouth of the shortest barrel ever employed.” and "weighed but one 12th of the charge" mutually exclusive statements. ie Can't both be true. This from the same caliber of scientists who bled deathly ill people to make them better and believed tomatoes were deathly poisonous.
Decades ago, I worked at the same indoor range where I competed. After every couple hours we had to sweep up the unburned smokeless powder from the floor about 15 ft in front of the firing line. My college room mate and I saved the unburned powder for knavish pranks and exploded a few things with it as well. One of the things I learned was to always tip my rifle up to shift the powder to the rear of the case before I leveled to aim and shoot. My scores increased by about 1% over holding the rifle down to load and then just raising it up to shoot. A little thing, but I was second in our intercollegiate league by my junior year. I know that we found lots of ash in what was collected from the cardboard when my buddy and I experimented with black powder fg loads 20 years ago. , but there was enough unburned black powder that the stuff we collected burned, though slowly, when lit with a match. Regardless of whether that was some form of imperfect carbon rich powder granules, it shows that some granules can escape conflagration, though most of the detritus was ash and cinder type material.

 

[Artificer]

And we may therefore safely conclude, that the powder is completely inflamed before the ball or shot arrives at the mouth of the shortest barrel ever employed.” and "weighed but one 12th of the charge" mutually exclusive statements. ie Can't both be true.

The explanation for what seems to be mutually exclusive statements is due to the fact that they didn't understand the grains of "ejecta" were burnt powder or bits of powder that could not burn because there was not enough oxygen around them.

Black Powder in the period was not and still is not so thoroughly mixed that every single grain of powder has the exactly correct proportions of charcoal, saltpeter and Sulphur in it. So the individual grains that did not have enough saltpeter in it or near it, would not burn in the barrel. Also, the grains coated or even partially coated by the burnt residue by other burnt powder, would be inhibited from burning or not burn at all, again because of that coating. Sort of like putting out a fire by putting dirt or other oxygen inhibitors/retardants on it.

Gus