why difference in powder charge?

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As happy as I am with my recent dive in and my 1858 revolver, I'm thinking I may end up with a 45 or 50 caliber sidelock percussion pistol. Let my inner pirate out. Aargh!

Anyway, I was perusing what is out there, etc. and got curious about loads (ie, how many shots per pound can I get?) and found this chart in the Traditions manual.

Since it seems the pistols are simply the rifles with a different stock and shorter barrel, I'm somewhat confused on the differences between the pistol min/max loads and the rifle min/max loads for what appears to be the same item, other than wood and barrel length.

Mind you, I'm used to thinking of max loads as a SAAMI spec for a metallic cartridge.... but are the differences here for pressure/safety reasons, or just because with the shorter barrel any more powder is wasted and expended as unneeded extra boom smoke and fire? I understand there will be a minimum needed that will change due to barrel length - gotta have enough go to reach the end without getting stuck. But I'm curious as to why the top end is double for the rifle vs. pistol.
You can do all what you want in any manner with any rifle or pistol : all is an affair of compromise between speed and accuracy, and in all test you'll terminate with a Gauss curve. The high of the curve will be the better compromise load/speed/barrel/twist rate and bullet and that would be like that with all the powders and charges that you'll try in/with any weapon : the highest point of the Gauss curve will be the highest point of the compromise between the speed, impact force and accuracy...
This is a valid for longs or shorts barrels from the smallest to the biggest caliber...
 
So @Artificer, the next question you’ll hear will be, “if that’s true, then why do longer barrels give higher velocities than shorter ones?” (All things equal of course and to a point of diminishing returns)

I know the answer, or think I do but you explained that first part so well…
 
So @Artificer, the next question you’ll hear will be, “if that’s true, then why do longer barrels give higher velocities than shorter ones?” (All things equal of course and to a point of diminishing returns)

I know the answer, or think I do but you explained that first part so well…

OK, that is a GREAT question that also causes a lot of confusion and continues the myth of powder burning the entire length of the barrel. So let's see if we can put that one to bed as well.

To explain this one, we have to use chemistry, the gas laws and basic elements of physics.

The powder burning completely in the barrel and in only a couple inches or so from the breech, causes gas pressure in the barrel. It is the gas pressure that forces the ball/projectile/shot down the barrel.

I'm not going to bore forum members to tears and causing them to nod off to sleep before the explanation of the gas laws is done, though. I think most people understand that gas pressure inside a container pushes equally against all sides or edges of the container. A common example of this, though, is when you add air pressure inside your vehicle's tires, that keeps the tires inflated equally all around in the rim with serviceable tires.

OK, so the powder is burnt entirely in only a couple inches from the breech, that raises gas pressure incredibly inside the barrel. That incredible pressure acts against against the patched ball or shot and out the vent hole, with equal pressure. However, because the Vent Hole isn't that big, there is plenty of gas pressure to force the patched ball/shot down the barrel.

Now is when we have to consider Newton's Laws of Motion. I'm going to list them, but won't go into great detail to explain them, as it isn't necessary.
  1. An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.
  2. The acceleration of an object depends on the mass of the object and the amount of force applied.
  3. Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first.

Law number 2 is very important to the question. The patched ball or shot column is the object the gas pressure has to move. It takes the most gas pressure force to begin to move it and less force to move and accelerate it down the barrel. Well, that's about as clear as mud, isn't it? OK, so let's give a somewhat similar example that almost everyone knows about.

Most of us have had to or at least seen someone or someone's pushing a car or other vehicle from the back. Those of us who have pushed the vehicle, know you have to push with the greatest force to begin to get the vehicle moving. Once it is moving, it takes less force to keep it moving and even going faster, once it has moved for a while. This is similar to what the gas pressure in a barrel does with a patched ball or shot column.

The gas pressure applies the greatest force on the ball/shot column near the breech where the "container" or space inside the barrel is at the smallest volume or least space inside the barrel. While the powder first begins to burn, it is building gas pressure until there is enough force to move the patched ball/shot column. Once the patched ball/shot column begins to move, that opens up the space inside the barrel behind the ball/shot column and the gas pressure begins to come down a bit once all the powder is burned.

So even though there is less gas pressure than what it took the ball/shot to initially move, the gas pressure continues to apply pressure against the projectile and the vent hole. There is less gas pressure as the "container" or open space behind the ball/shot increases in size as the ball/shot is driven, but there is still plenty of gas pressure to keep accelerating the ball/shot as long as the ball/shot is still in the barrel. Thus, the longer the barrel, the faster the ball/shot moves, until the ball/shot exits at the muzzle. (Now there is a length of a barrel that would be long enough to see the ball/shot actually eventually slow down inside the barrel, but that length of barrel is MUCH longer than any single person is going to carry.)

IOW, it is not the powder that continues to burn and causes the ball/shot to speed up inside the barrel, but rather the gas pressure from the burned powder that does it. So for our purposes, the longer the barrel we are willing to carry, the faster the ball/shot will travel inside the barrel and give the most velocity to the ball/projectile when it leaves the barrel muzzle.

Gus

P.S. Newton's 3rd Law is what gives us felt recoil after the shot goes off.

  • 3. Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first.
Inside gun barrels, there is force applied to move the ball/shot and an equal amount acts against the gun and thus our hands or shoulder. However, since the ball/shot is much smaller in mass/weight than the gun, we are not propelled backward as fast and with as much force as the ball/shot is propelled out of the barrel.

Gus
 
OK, that is a GREAT question that also causes a lot of confusion and continues the myth of powder burning the entire length of the barrel. So let's see if we can put that one to bed as well.

To explain this one, we have to use chemistry, the gas laws and basic elements of physics.

The powder burning completely in the barrel and in only a couple inches or so from the breech, causes gas pressure in the barrel. It is the gas pressure that forces the ball/projectile/shot down the barrel.

I'm not going to bore forum members to tears and causing them to nod off to sleep before the explanation of the gas laws is done, though. I think most people understand that gas pressure inside a container pushes equally against all sides or edges of the container. A common example of this, though, is when you add air pressure inside your vehicle's tires, that keeps the tires inflated equally all around in the rim with serviceable tires.

OK, so the powder is burnt entirely in only a couple inches from the breech, that raises gas pressure incredibly inside the barrel. That incredible pressure acts against against the patched ball or shot and out the vent hole, with equal pressure. However, because the Vent Hole isn't that big, there is plenty of gas pressure to force the patched ball/shot down the barrel.

Now is when we have to consider Newton's Laws of Motion. I'm going to list them, but won't go into great detail to explain them, as it isn't necessary.
  1. An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.
  2. The acceleration of an object depends on the mass of the object and the amount of force applied.
  3. Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first.

Law number 2 is very important to the question. The patched ball or shot column is the object the gas pressure has to move. It takes the most gas pressure force to begin to move it and less force to move and accelerate it down the barrel. Well, that's about as clear as mud, isn't it? OK, so let's give a somewhat similar example that almost everyone knows about.

Most of us have had to or at least seen someone or someone's pushing a car or other vehicle from the back. Those of us who have pushed the vehicle, know you have to push with the greatest force to begin to get the vehicle moving. Once it is moving, it takes less force to keep it moving and even going faster, once it has moved for a while. This is similar to what the gas pressure in a barrel does with a patched ball or shot column.

The gas pressure applies the greatest force on the ball/shot column near the breech where the "container" or space inside the barrel is at the smallest volume or least space inside the barrel. While the powder first begins to burn, it is building gas pressure until there is enough force to move the patched ball/shot column. Once the patched ball/shot column begins to move, that opens up the space inside the barrel behind the ball/shot column and the gas pressure begins to come down a bit once all the powder is burned.

So even though there is less gas pressure than what it took the ball/shot to initially move, the gas pressure continues to apply pressure against the projectile and the vent hole. There is less gas pressure as the "container" or open space behind the ball/shot increases in size as the ball/shot is driven, but there is still plenty of gas pressure to keep accelerating the ball/shot as long as the ball/shot is still in the barrel. Thus, the longer the barrel, the faster the ball/shot moves, until the ball/shot exits at the muzzle. (Now there is a length of a barrel that would be long enough to see the ball/shot actually eventually slow down inside the barrel, but that length of barrel is MUCH longer than any single person is going to carry.)

IOW, it is not the powder that continues to burn and causes the ball/shot to speed up inside the barrel, but rather the gas pressure from the burned powder that does it. So for our purposes, the longer the barrel we are willing to carry, the faster the ball/shot will travel inside the barrel and give the most velocity to the ball/projectile when it leaves the barrel muzzle.

Gus

P.S. Newton's 3rd Law is what gives us felt recoil after the shot goes off.

  • 3. Whenever one object exerts a force on another object, the second object exerts an equal and opposite on the first.
Inside gun barrels, there is force applied to move the ball/shot and an equal amount acts against the gun and thus our hands or shoulder. However, since the ball/shot is much smaller in mass/weight than the gun, we are not propelled backward as fast and with as much force as the ball/shot is propelled out of the barrel.

Gus

Thanks Gus... that’s just what I was going to say... 😁

Kidding aside, it’s good to understand the science behind whatever you’re pursuit happens to be. As much as is possible for each of our given and disparate abilities to understand it.
 
The recoil factor of a rifle sized powder charge in a side lock pistol IS the Key that too often is overlooked. There would not be that much additional recoil IF the rifle sized powder charge was not burning as much as it would burn inside the pistol length barrel.



Folks, I don't mean to criticize anyone personally, but there are a few times in this thread people have continued an old Myth about how black powder burns in a barrel. That Myth is basically and supposedly that a black powder charge continues to burn in most of, if not the entire length of a barrel. Well, that is just not true and they actually figured that out about 270 years ago, but the Myth continues today.

In 1751, the Royal Society of London conducted tests to see how far down the barrel the powder charge would burn. They found in pistol barrels that it only took One Single Inch of barrel beyond the ball, for the powder charge to burn completely. That's correct, only One Single Inch.

They did notice a few specks of what too many folks then and way too many folks today still believe were unburned "good" powder. HOWEVER, the Royal Society correctly identified those unburned specs as powder that would not have gone off in the barrel - no matter how long the barrel was. Now, why is that?

Even with the barrel of a flintlock having an open hole/vent in the barrel, there has to be SOMETHING in the black powder itself, that will cause it to burn. That means part of the mixture of the black powder has to supply oxygen while the powder is burning and is known in chemistry as an oxidizer. The Saltpeter in the black powder is the oxidizer and provides the oxygen for the black powder to burn inside the barrel. Additional Oxygen cannot get into the barrel from the vent hole once the powder begins burning, because the gas pressure of the burning powder keeps forcing air out of the barrel.

Now even as I write this, I can hear folks disagreeing because of one of two things they have observed or read about, so let's discuss them. O

The first bone of contention is a period practice that some folks still do today and that is firing ever larger charges of powder over snow or a large piece of cloth or canvas. Once the powder charge is increased enough, one will notice specks of what looks like good powder on the snow or cloth. In fact, those specks are not good powder at all and are known in Chemistry as "Ejecta." Those specks are one of two things, 1. Already burnt pieces of powder or 2. pieces of powder that didn't have enough Saltpeter to set them off or were covered by burnt material that didn't allow them to burn inside the barrel NO MATTER how long the barrel was or could be.

The second bone of contention is when Muzzle Flash is seen from the side and one see's little sparks inside or just outside the flash. AH-HA!! That must be good unburnt powder specks, right? Nope, what you are seeing there is the Ejecta that is burning ONLY because the super heated gas from the powder hits the Oxygen in the air and raises the temperature of the Ejecta enough to burn it up there, when it would never have burned in the barrel.

The bottom line takeaway from all this is it only takes a few inches near the breech plug for ALL black powder to burn inside a barrel that will ever burn inside a barrel, no matter how long that barrel is.

OK, so MOST of us don't and will never have the super expensive scientific test equipment to prove this, so is there something observable that will prove it? Yes, absolutely.

The observable proof of this is the higher felt recoil in a pistol with rifle size powder charges and what helped cause the Grip of ADK Bigfoot's to snap in two on his Lyman Pistol. IF the rifle powder charge required a much longer length of barrel to burn, then the powder charge would not burn up completely inside the Lyman Pistol Barrel and could not have caused enough recoil from higher gas pressure that helped the grip snap in two. Now I suspect the wood grain of Bigfoot's grip also did not follow the grip, so that made it easier to snap off in two, but it would still not have done so had there not been the gas pressure from the entire rifle powder charge going off inside the barrel.

Gus

This is interesting. Perhaps it is indeed ejecta(and increased pressure/temperature of gas) that causes many times larger muzzle flash when I load my short barreled howdah with 70 grains rather than 50.

Gus, do you by any chance remember the name of the publication they published those results in? (or any other details that can help me to find that publication) I have an interest in collecting such texts.
 
Thanks Gus... that’s just what I was going to say... 😁

Kidding aside, it’s good to understand the science behind whatever you’re pursuit happens to be. As much as is possible for each of our given and disparate abilities to understand it.

Thank you for the kind words.

I think the information is valuable especially when we consider barrel lengths in our guns and powder charges.

Gus
 
This is interesting. Perhaps it is indeed ejecta(and increased pressure/temperature of gas) that causes many times larger muzzle flash when I load my short barreled howdah with 70 grains rather than 50.

Muzzle Flash is caused by the super heated gas hitting the oxygen in the air after the projectile leaves the muzzle. The super heated gas actually ignites oxygen in the air and that's what gives you the flash. So when you increased your powder charge 40 percent when going from 50 to 70 grains in your Howdah, the larger amount of super heated gas will cause the larger muzzle flash, as you found.

Gus, do you by any chance remember the name of the publication they published those results in? (or any other details that can help me to find that publication) I have an interest in collecting such texts.

Yes, I do remember (wonder of wonders), but I'm not sure the original documentation is still easily available online. I found it around 8 years ago, lost it when I got a new computer, then I haven't been able to find it since.

It was originally published in the Papers of the London Royal Society and the information came from that source.

Royal Society | British science society | Britannica

History of the Royal Society | Royal Society

Royal Society - Wikipedia

Gus
 
During the civil war the confederacy authorized privateers against the Union shipping . Is there a difference between “Privateer and Pirate”?
First let me say; Lots of good and interesting information given here to taken in!

Now to answer your question Whughett, since it was asked; yes there is a difference between 'privateer' and 'pirate'. In short; one hunted legally (privateer) and one hunted illegally (pirate). A privateer generally sailed with a Letter of Mark, a mercenary of sorts, and the other took a ship whenever they damn well pleased.
.....btw, there were still "pirates" in the 1800s just as there are still today, just not the typical stereotype as summed up in the mind when one today mentions "Pirate" (Jack Sparrow and Dizzyland aside)
 
"Letters of marque allowed governments to fight their wars using private captains and sailors, akin to mercenary soldiers, to hunt down enemies and fight their wars instead of using their navies. Oftentimes it was cheaper and easier for governments to issue letters of marque to privateers than to maintain a longstanding navy. Instead of building, funding, and maintaining a navy in times of peace and in times of war, governments would issue letters of marque to privateers so they could fight the nation's battles. This way, the government issuing the letter of marque were not responsible to fix or maintain any of the privateers' ships since they were owned by the privateers."

Letter of marque - Wikipedia

Gus
 
There is not enough barrel and the excess powder will blow out unburned anyway.

Using 100gr of musket powder in a .69 flintlock pistol would be senseless.

My .54 Harper's Ferry smoothbore pistol uses about a 35 gr charge of 3f, which is equivalent to the original charge of "pistol powder". No way would I put 80gr of powder in that. Probably crack the wood, or just produce excessive recoil with no advantage ballistically

However, a Walker uses a 60gr charge which is equal to a .58 Minie service charge. Obviously the projectile is smaller but most .45 rifles don't use 60gr of powder.
 
A very good summation, Gus. Please let me pick one small nit. Oxygen does not, can not burn. It is a great enabler of burning in other materials, but it is totally incapable of burning, itself.

Spence

Yes, you are right Spence and thank you for correcting me.

What I should have written was something like once the superheated gas hits the oxygen in the air, it helps the gas to ignite rather spectacularly into what we commonly know as muzzle flash.

Gus
 
There is not enough barrel and the excess powder will blow out unburned anyway.

Using 100gr of musket powder in a .69 flintlock pistol would be senseless.

Powder is not going to blow out unburned, it will all burn up in the first two to three inches of the bore. You are absolutely correct about 100 grains being senseless in a .69 cal. pistol.

My .54 Harper's Ferry smoothbore pistol uses about a 35 gr charge of 3f, which is equivalent to the original charge of "pistol powder". No way would I put 80gr of powder in that. Probably crack the wood, or just produce excessive recoil with no advantage ballistically

That's correct because all the powder burns up in the first few inches of the barrel.

However, a Walker uses a 60gr charge which is equal to a .58 Minie service charge. Obviously the projectile is smaller but most .45 rifles don't use 60gr of powder.

I think you meant to type "but most .44 revolvers don't use 60 gr of powder?"

Gus
 
Muzzle Flash is caused by the super heated gas hitting the oxygen in the air after the projectile leaves the muzzle. The super heated gas actually ignites oxygen in the air and that's what gives you the flash. So when you increased your powder charge 40 percent when going from 50 to 70 grains in your Howdah, the larger amount of super heated gas will cause the larger muzzle flash, as you found.



Yes, I do remember (wonder of wonders), but I'm not sure the original documentation is still easily available online. I found it around 8 years ago, lost it when I got a new computer, then I haven't been able to find it since.

It was originally published in the Papers of the London Royal Society and the information came from that source.

Royal Society | British science society | Britannica

History of the Royal Society | Royal Society

Royal Society - Wikipedia

Gus

The paper published by the Royal Society itself at the time had a title "Philosophical Transactions". Everything that was published in it is available at Journals | Royal Society with a pretty good search interface.

Unfortunately, despite searching using keyword gunpowder I haven't found any publication around that time (+-50 years) with a title describing such experiment. However I did find one article titled "Experiments to determine the force of fired gunpowder" from 1797. That article is 73 pages so I didn't read it in its entirety (as it was published way after the date in question), but while skimming I noticed on page number 236 the following excerpt.

I shall, therefore, only observe at present, that the results of all my inquiries tended to confirm me more and more in the opinion, that the theory generally adopted relative to the explosion of gunpowder was extremely erroneous, and that its force is in fact much greater than is generally imagined. That the position of Mr. Robins, which supposes the inflammation and combustion of gunpowder to be so instantaneous "that the whole of the charge of a piece of ordnance is actually inflamed and converted into elastic vapour before the bullet is sensibly moved from its place" is very far from being true.

So this tells us there was a Mr. Robins that published some paper in which he made the above claim prior to 1797. There is a book titled "New principles of gunnery" written by Benjamin Robins(1707-1751). Full text is available in Internet archive. The book is a collection of articles published at various dates including around 1747~1751. The first article is "New principles of gunnery" as read before the Royal Society in 1748.

On page 74 there is proposition 7 and its point 2 is the quote we saw before "That all the powder of the charge is fired,
and converted into an elastic fluid, before the
bullet is sensibly moved from its place"

There is further elaboration of this claim and a description of an experiment on page 80

I considered, that, if part only of the powder is fired, and that successively, then by laying a greater weight before the charge, (suppose 2 or 3 bullets instead of one) a greater quantity of powder would necessarily be fired, since a heavier weight would be a longer time in passing through the barrel. Whence it should follow, that two or three bullets would be
impelled by a much greater force than one only. But the contrary to this appears by experiment ; for firing one, two, and three bullets, laid contiguous to each other, with the same charge respectively, I have found ( by a method to be mentioned hereafter) that their velocities were not much different from the reciprocal of the subduplicate of their quantities of matter

Further he describes how he measured the muzzle velocities "in 1in barrel" for 1,2 or 3 bullets. No information is given on if the barrel indeed was only 1in or longer barrel was used with results calculated or what the caliber was. Number wise only velocities are given. He notes there was some excess velocity for 2 and 3 bullets, but he claims it can be explained "the flame escaping around the first bullet and acting on the bases of second and third". The extra velocities are around 4% more than expected so not much.

So in modern speak :) the author attempts to establish a given amount of powder will inpart same total energy to a lighter or heavier projectile in a very short barrel. If powder was burning partially a heavier projectile, spending more time in the barrel should have much more muzzle energy than 4% observed.

So there you have it. Is it enough to believe black powder burns completely in the first inch of the barrel? Perhaps.
 
The paper published by the Royal Society itself at the time had a title "Philosophical Transactions". Everything that was published in it is available at Journals | Royal Society with a pretty good search interface.

Unfortunately, despite searching using keyword gunpowder I haven't found any publication around that time (+-50 years) with a title describing such experiment. However I did find one article titled "Experiments to determine the force of fired gunpowder" from 1797. That article is 73 pages so I didn't read it in its entirety (as it was published way after the date in question), but while skimming I noticed on page number 236 the following excerpt.



So this tells us there was a Mr. Robins that published some paper in which he made the above claim prior to 1797. There is a book titled "New principles of gunnery" written by Benjamin Robins(1707-1751). Full text is available in Internet archive. The book is a collection of articles published at various dates including around 1747~1751. The first article is "New principles of gunnery" as read before the Royal Society in 1748.

On page 74 there is proposition 7 and its point 2 is the quote we saw before "That all the powder of the charge is fired,
and converted into an elastic fluid, before the
bullet is sensibly moved from its place"

There is further elaboration of this claim and a description of an experiment on page 80



Further he describes how he measured the muzzle velocities "in 1in barrel" for 1,2 or 3 bullets. No information is given on if the barrel indeed was only 1in or longer barrel was used with results calculated or what the caliber was. Number wise only velocities are given. He notes there was some excess velocity for 2 and 3 bullets, but he claims it can be explained "the flame escaping around the first bullet and acting on the bases of second and third". The extra velocities are around 4% more than expected so not much.

So in modern speak :) the author attempts to establish a given amount of powder will inpart same total energy to a lighter or heavier projectile in a very short barrel. If powder was burning partially a heavier projectile, spending more time in the barrel should have much more muzzle energy than 4% observed.

So there you have it. Is it enough to believe black powder burns completely in the first inch of the barrel? Perhaps.

I'm sorry, that isn't the paper I was referring to, though the use of the term "elastic vapor" for gas pressure I've run across a few times.

In the article/paper I'm referring to, they actually counted the individual bits of ejecta particulates, though that is not what they called it. Not sure if that helps find it or not, but it should.

Also the paper concluded that if there was an inch of pistol barrel beyond the loaded ball, that the powder inside did indeed burn up.

Gus
 
First let me say; Lots of good and interesting information given here to taken in!

Now to answer your question Whughett, since it was asked; yes there is a difference between 'privateer' and 'pirate'. In short; one hunted legally (privateer) and one hunted illegally (pirate). A privateer generally sailed with a Letter of Mark, a mercenary of sorts, and the other took a ship whenever they damn well pleased.
.....btw, there were still "pirates" in the 1800s just as there are still today, just not the typical stereotype as summed up in the mind when one today mentions "Pirate" (Jack Sparrow and Dizzyland aside)
LOL. Guess any high school graduate would know the legal definition. Depended on which side one was on. Privateer to the Confederates pirates to the Union. And the Union most likely treated them as such if captured.
 
So @Artificer, the next question you’ll hear will be, “if that’s true, then why do longer barrels give higher velocities than shorter ones?” (All things equal of course and to a point of diminishing returns)

I know the answer, or think I do but you explained that first part so well…
During the civil war the confederacy authorized privateers against the Union shipping . Is there a difference between “Privateer and Pirate”?
A pirate was on his own and had no safe haven? A privateer was hired by a country and a safe place to go for supplies and repairs, other than that they were the same, ruthless!
 
LOL. Guess any high school graduate would know the legal definition. Depended on which side one was on. Privateer to the Confederates pirates to the Union. And the Union most likely treated them as such if captured.
Are you talking about recent high school grads or grads of 50 years ago?
 
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