4F Black Powder Question

[Carbon 6]

Here are some excerpts from the experts who experimented over a 170 years ago and blew up a lot of guns.



"Another advantage of using gunpowder of a suitable granulation is the absence of sharp recoil; and thus greater accuracy of range is obtained—accuracy of range and steadiness of weapon being inseparable.

Large-grain gunpowder is not only a more effectual expellant than the fine grain, but is much more safe to use, for by using it the risk of bursting the barrel is much lessened; as a very simple illustration will show. If we estimate the force generated by the usual charge of 21⁄2 drachms (I confine the question to the 14-bore gun, for uniformity) to be 5,000 lbs., whether the powder be fine or coarse grain, it follows that the fine powder, igniting so rapidly, will exert all its force on the breech end of the gun; whereas the coarse powder, igniting less rapidly, distributes this force over the whole length of the barrel: hence the greater risk of a gun bursting with fine powder than with coarse. If we suppose the fine powder to be entirely ignited when it reaches half way up the barrel, then the force of 5,000 lbs. is exerted on the lower half of the barrel; but if the coarser grain is not entirely ignited until it reaches[36] the muzzle, then the force of 5,000 lbs. will be distributed over the whole length of the gun.


Fine grain, when unconfined, explodes quicker than large, or is sooner burnt out, and consequently generates more force in the same period of time; but when it comes to large quantities, its very quickness is detrimental to its force, by condensing the air around the exterior of the mass of fluid which thus constrains its bound. In small quantities, the proportion of condensation is not so apparent, and hence the reason why greater velocities can be obtained with small arms than with cannon."

 

[SDSmlf]

Here are some excerpts from the experts who experimented over a 170 years ago and blew up a lot of guns.



"Another advantage of using gunpowder of a suitable granulation is the absence of sharp recoil; and thus greater accuracy of range is obtained—accuracy of range and steadiness of weapon being inseparable.

Large-grain gunpowder is not only a more effectual expellant than the fine grain, but is much more safe to use, for by using it the risk of bursting the barrel is much lessened; as a very simple illustration will show. If we estimate the force generated by the usual charge of 21⁄2 drachms (I confine the question to the 14-bore gun, for uniformity) to be 5,000 lbs., whether the powder be fine or coarse grain, it follows that the fine powder, igniting so rapidly, will exert all its force on the breech end of the gun; whereas the coarse powder, igniting less rapidly, distributes this force over the whole length of the barrel: hence the greater risk of a gun bursting with fine powder than with coarse. If we suppose the fine powder to be entirely ignited when it reaches half way up the barrel, then the force of 5,000 lbs. is exerted on the lower half of the barrel; but if the coarser grain is not entirely ignited until it reaches[36] the muzzle, then the force of 5,000 lbs. will be distributed over the whole length of the gun.


Fine grain, when unconfined, explodes quicker than large, or is sooner burnt out, and consequently generates more force in the same period of time; but when it comes to large quantities, its very quickness is detrimental to its force, by condensing the air around the exterior of the mass of fluid which thus constrains its bound. In small quantities, the proportion of condensation is not so apparent, and hence the reason why greater velocities can be obtained with small arms than with cannon."

Expert source?

And for what it is worth, blowing up guns was and is not limited to blackpowder. Had a number of conversations with a fellow named **** Casull about blowing up handguns with smokeless years ago, just not a topic for this forum.

 

[Carbon 6]

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[SDSmlf]

.

So no source to reference? Or just a fat finger moment?

 

[Britsmoothy]

Here are some excerpts from the experts who experimented over a 170 years ago and blew up a lot of guns.



"Another advantage of using gunpowder of a suitable granulation is the absence of sharp recoil; and thus greater accuracy of range is obtained—accuracy of range and steadiness of weapon being inseparable.

Large-grain gunpowder is not only a more effectual expellant than the fine grain, but is much more safe to use, for by using it the risk of bursting the barrel is much lessened; as a very simple illustration will show. If we estimate the force generated by the usual charge of 21⁄2 drachms (I confine the question to the 14-bore gun, for uniformity) to be 5,000 lbs., whether the powder be fine or coarse grain, it follows that the fine powder, igniting so rapidly, will exert all its force on the breech end of the gun; whereas the coarse powder, igniting less rapidly, distributes this force over the whole length of the barrel: hence the greater risk of a gun bursting with fine powder than with coarse. If we suppose the fine powder to be entirely ignited when it reaches half way up the barrel, then the force of 5,000 lbs. is exerted on the lower half of the barrel; but if the coarser grain is not entirely ignited until it reaches[36] the muzzle, then the force of 5,000 lbs. will be distributed over the whole length of the gun.


Fine grain, when unconfined, explodes quicker than large, or is sooner burnt out, and consequently generates more force in the same period of time; but when it comes to large quantities, its very quickness is detrimental to its force, by condensing the air around the exterior of the mass of fluid which thus constrains its bound. In small quantities, the proportion of condensation is not so apparent, and hence the reason why greater velocities can be obtained with small arms than with cannon."

That's a good find and paragraph 3 does make a lot of sense indeed. Indeed it resembles something I said way back in this thread.
However, paragraph 2 is full of "suppose"! Unfortunately whilst in essence true an assumption creeps in with regards to safety.
The same author up to now submits no accounts of failures via a fine powder!
He or they are linking felt recoil to a supposed danger that is still not demonstrated.
Thanks for the passage.

B.

 

[fsrmg1]

I'd limit it to 50 grains max in a .45 cal with a PRB.

 

[Carbon 6]

So no source to reference? Or just a fat finger moment?

I posted the source, then purposefully deleted it.
I've posted the source before in other arguments, don't think anyone read it.

 

[azmntman]

well that makes sense....helpful here for sure.

 

[VADSLRAM]

This is old but following it back and forth there is quite a bit of good science.
https://firearmshistory.blogspot.com/2016/07/black-powder-iii.html

It must be remembered that before the invention of smokeless powder in the latter part of the 19th century, people used black powder for everything from the smallest pistol to large cannon. Therefore, they had to have different types of black powder to accomodate all these weapon types. In England, smoothbore weapons were used as well as rifled weapons. For instance, the Brown Bess musket (which is a muzzle loading smoothbore weapon) was produced by the British from 1722 to about 1860 or so.

We noted a couple of posts ago, that the average size of the grains is a huge factor in the combustion rate of gunpowder. With the introduction of rifled guns, it was considered a good idea to use a powder that would burn more gradually and strain the gun less, than the powder then in use for smoothbore guns. Rifled guns do more work than smoothbores because not only do they impart a forward velocity on the projectile, they also introduce a rotational velocity to it. The weight of projectiles in a rifled gun also tends to be greater than that of a smoothbore gun of the same caliber. For example, an 8-inch rifled cannon of that era threw a projectile of weight 180 lbs., whereas the standard load for a 8-inch smooth bore cannon was a 68 lbs. ball.

For larger cannon, a powder designated as "Large Grain" or L.G. was used, until the advent of rifled cannon, at which point a powder called R.L.G (Rifled Large Grain) was introduced. This powder worked well for cannon of smaller caliber, but when guns of 7 inches and larger calibers were introduced, it was found advisable to use a slower burning powder than R.L.G, at which point, Pebble powders (P and P2) were introduced. These were larger grain powders of cubical-shaped grains. P powder grains were about 5/8 inch per side and P2 powder grains were 1.5 inch cubes. We will study the manufacture of these powders in a later post.

For small arms, a more rapidly burning powder is required, and therefore these are much smaller grains on average than the ones above. In England, there were four grades of powder produced for small arms:

1. Fine Grain (F.G.) powder to be used by smoothbore firearms (e.g.) the Brown Bess musket. This powder was also used for the charge of 7 pounder muzzle loading cannon and for the bursting charge of shrapnel shells.
2. Rifle Fine Grain (R.F.G.) powder, to be used by most rifled small arms, except the Martini-Henry rifle and pistols.
3. Rifle Fine Grain 2 (R.F.G.2) powder, to be used by the Martini-Henry cartridge.
4. Pistol powder, to be used by pistols and revolvers such as the Colt Single Action revolver and the Deane-Adams revolvers. This is a quick burning powder and is suitable for shorter barrels, where a slower burning powder would not finish burning within the barrel completely. Since it is a very quick burning powder, it was also used for shrapnel shells.

 

[Britsmoothy]

This is old but following it back and forth there is quite a bit of good science.
https://firearmshistory.blogspot.com/2016/07/black-powder-iii.html

Another source that backs the fact that a fine powder burns slowly once compressed
Thank you.

 

[George]

Another source that backs the fact that a fine powder burns slowly once compressed
Thank you.

The old boys understood that to be the case very early on. An excerpt from Pteryplegia: or the Art of Shooting-Flying, A Poem, by George Markland, 1727, explains that if you prime too full the pressure of the frizzen/steel on the prime will retard ignition.

Nor Prime too full, else you will surely blame
The hanging fire and lose the pointed Aim.
Should I of This the obvious Reason tell:
The caking Pressure does the Flame repel
And Vulcan's lamed again by his own Steel.

Spence

 

[user 36911]

A possible problem that I can see with using 4F as a main charge is from a noob.

He reads that 4F is fine for a main charge. He also reads a lot of guys use 150gr of powder. (inlines) He puts those together and pours 150gr of 4F into a foreign barrel that hasn't been proof tested. That may not be a problem but I won't be the one pulling the trigger. You go first.

I use 3F for main charge and the pan. I don't have much use for 4F powder. It sucks up too much moisture.

 

[Britsmoothy]

A possible problem that I can see with using 4F as a main charge is from a noob.

He reads that 4F is fine for a main charge. He also reads a lot of guys use 150gr of powder. (inlines) He puts those together and pours 150gr of 4F into a foreign barrel that hasn't been proof tested. That may not be a problem but I won't be the one pulling the trigger. You go first.

I use 3F for main charge and the pan. I don't have much use for 4F powder. It sucks up too much moisture.

But 150g 3f would be fine!

It doesn't work like that.
In essence the finer powder chokes itself when in a loaded form. It becomes a near solid. More so once compression starts. The front of the volume of powder possibly gets sent so far up the barrel with the projectile.
This is why we see an increase of pressure BUT NOT A DANGEROUS AMOUT OF PRESSURE INCREASE ( NOT SHOUTING JUST EMPHASING). The increase is from reduced combustion chamber dimensions and an increase in projectile weight MOMENTARILY.
Caps for emphasis only.

 

[Nameless Hunter]

But 150g 3f would be fine!

It doesn't work like that.
In essence the finer powder chokes itself when in a loaded form. It becomes a near solid. More so once compression starts. The front of the volume of powder possibly gets sent so far up the barrel with the projectile.
This is why we see an increase of pressure BUT NOT A DANGEROUS AMOUT OF PRESSURE INCREASE ( NOT SHOUTING JUST EMPHASING). The increase is from reduced combustion chamber dimensions and an increase in projectile weight MOMENTARILY.
Caps for emphasis only.

An interesting video on efforts to overcharge a muzzleloader.

 

[TNGhost]

I say those of us who understand our firearms, work with them and know how they operate and how to operate them properly go on using 4f as we have, as it works very well and is the best choice in many situations.

Those that don't know or understand muzzleloading firearms as well, can continue to use whatever their emotions tell them too.

 

[mooman76]

There are always going to be new bees that jump in not knowing the facts and put it the wrong powders. Like the ones that put in smokeless. All we can do is advise them but if they don't let someone know, or ask someone who knows, we can't help them.

 

[Britsmoothy]

There are always going to be new bees that jump in not knowing the facts and put it the wrong powders. Like the ones that put in smokeless. All we can do is advise them but if they don't let someone know, or ask someone who knows, we can't help them.

Other than smokeless what are the other wrong powders?

 

[azmntman]

4F SILLY!!

LOL

sorry, couldnt help it!

 

[Britsmoothy]

4F SILLY!!

LOL

sorry, couldnt help it!

New bees.....

 

[Britsmoothy]

My friend Carbon 6 sent me a link to Gunnery 1858 by William Greener.

He extols the many assumptions made against fine powders over courser grains.
But then after his opinions writes this paragraph.
"There can be no doubt of the importance of this principle; little progress has, however, been effected from want of scientific illustration; let it be defined like that of steam power, and its adoption will follow as a natural consequence."

Here we have a clear admission that he has no scientific proof on what he previously assumes takes place but he is absolutely correct in one thing!
It has been clearly adopted as in, my word, gospel!
Where as the real gospels do indeed stand up to scrutiny this one above certainly does not.......so far!