Powder for Longer or Shorter Barrels.

[Brazos John]

Use FFFg powder for your carbine. You need a faster burning powder for the shorter barrel.

I had never thought about this, but it sure makes sense.
I have both long and short barrels, but haven't consider the length when loading my horn.

So, the way I understand it:
1. When you want the max push to the ball, it seems you would want the powder to burn completely in the barrel. So, use a faster-burning powder?
2. When you want flame and smoke, you want unburned powder flying out the muzzle and igniting. And use a slower-burning powder?

So, does the grind actually make much of a difference, or is it more a function of the volume of powder used?
What do y'all think?

 

[Rich44]

I think you are correct and feel that way to.

 

[Phil Coffins]

I’ve been basing the powder on the bore size rather than the length. 12 gauge gets Fg and 36 gets FFFg . My 1 3/4” bore cannon uses cannon grade which looks like black rice but in scale the barrel is a short twenty nine inches.

 

[Rich44]

My 1 3/4” bore cannon uses cannon grade which looks like black rice but in scale the barrel is a short twenty nine inches.

Me thinks you want that:
2. When you want flame and smoke, you want unburned powder flying out the muzzle and igniting. And use a slower-burning powder?

 

[chorizo]

It is the grind. More surface area exposed to oxygen and surface to burn.

Bore size makes a difference also as there is more room for expansion and thus more complete burn.

In short, volume of area to burn, the physical condition of what you are burning.

Faster burn mean quicker and higher pressure peak with resulting increase in velocity

Add heavier bullet weight and the increase of static inertia to overcome results in a smaller space to burn and a resultant increase in pressure and velocity.

@Brazos John Play with this calculator: Look at pressure peak, barrel lengths, grind and volume (caliber) and you will get a feel for what I mean

https://www.p-max.uk/cgi-bin/black_powder.cgi
On powder:

Black powder​

Main article: Gunpowder
Gunpowder (Black powder) is a finely ground, pressed and granulated mechanical pyrotechnic mixture of sulfur, charcoal, and potassium nitrate or sodium nitrate. It can be produced in a range of grain sizes. The size and shape of the grains can increase or decrease the relative surface area, and change the burning rate significantly. The burning rate of black powder is relatively insensitive to pressure, meaning it will burn quickly and predictably even without confinement,[12] making it also suitable for use as a low explosive. It has a very slow decomposition rate, and therefore a very low brisance. It is not, in the strictest sense of the term, an explosive, but a "deflagrant", as it does not detonate but decomposes by deflagration due to its subsonic mechanism of flame-front propagation.

 

[Flint62Smoothie]

Personally, I think there's a balance to be played between bore size and barrel length. Now each fire lock was clearly only a sample of one unto itself, however some patterns emerged.

• 41" 62-cal Caywood barrel - Would develop a difficult to remove 'crud ring' 8 to 10" before the muzzle with 3Fg powder, where 2Fg was fine (roundball loads)
• 48" 62-cal Greg Christian barrel - Shot great with 2Fg until loads were 'heavy', like getting close to 100-grains, where1Fg was great (roundball loads)
• 54" 65-cal The Rifle Shoppe barrel - Shot awesome with 1Fg powder (roundball loads)
• 60" 75-cal Greg Christian barrel - Shot awesome with 1Fg powder with 'heavy' (~100-grn) loads performing the best out of paper cartridges. Won many a woodswalk with it and once placed 2nd only to a rifle using her ... but got too many complaints that I was too close to the target, LOL ... and it tended to destroy the smaller gongs ... (roundball loads). Shot loads are spectacular with 1Fg!

TIP for shot shooters - 1Fg gives a 'softer' start and really improves your patterns with heavy loads! Try it!

 

[chorizo]

Personally, I think there's a balance to be played between bore size and barrel length. Now each fire lock was clearly only a sample of one unto itself, however some patterns emerged.

• 41" 62-cal Caywood barrel - Would develop a difficult to remove 'crud ring' 8 to 10" before the muzzle with 3Fg powder, where 2Fg was fine (roundball loads)
• 48" 62-cal Greg Christian barrel - Shot great with 2Fg until loads were 'heavy', like getting close to 100-grains, where1Fg was great (roundball loads)
• 54" 65-cal The Rifle Shoppe barrel - Shot awesome with 1Fg powder (roundball loads)
• 60" 75-cal Greg Christian barrel - Shot awesome with 1Fg powder with 'heavy' (~100-grn) loads performing the best out of paper cartridges. Won many a woodswalk with it and once placed 2nd only to a rifle using her ... but got too many complaints that I was too close to the target, LOL ... and it tended to destroy the smaller gongs ... (roundball loads). Shot loads are spectacular with 1Fg!

TIP for shot shooters - 1Fg gives a 'softer' start and really improves your patterns with heavy loads! Try it!

Note the length of the barrels he is talking about using 1 f with.
I have fence posts shorter than many of those.

Not one of those, unless they were cut in to two, would qualify as a carbine.

Also "heavy" 100 grains of 2f in a 62 cal? I am using 110 grains of T7 FFFg in a 54 cal.

 

[BS]

Now that I found the Pmax calculator from above post.

It explained why my 7 bore with shot is slow.

7 bore slow powder, right? Well maybe.

any way the Pmax showed that a 115 grain load of

1F only has an 88% burn in 27"s.

2f has a 96% burn

3f has a 99% burn

Will the shot like the pressure of 3f, probably not, but I need to find out.

The advantage of 3f is one powder measure for shot and powder, and gain 100 fps with a 115 gr load.

Pmax also shows that I should be burning 3f in my 25" .62 rifle for a 99% burn.

The amount and type of powder varies the % burn rate, so you need to try different Fs and amounts.

Pmax info is just a suggestion, you really need to try some loads and see how they preform in your gun!

[ just for info, I get the best patterns with 1F in the 7 bore]

 

[Sam squanch]

My very old gunsmith book-1885- says to use coarse powder in a long barrel, no matter what the caliber. And use fine powder in a short barrel, no matter what the caliber.

 

[hanshi]

I honestly have no idea. All I can say for sure is that I have nothing except 3F powder, right now, and use it in everything. I don't hunt so have little use for heavy loads. I do think I may have a few ounces of 2F because I remember testing loads in my 20 ga smoothbore some years back and found no significant difference between 3F and 2F. I do know 3F burns faster and generally gives higher velocities than the same load of 2F. So I just use what works for my limited use.

 

[longcruise]

Ive never bought into the unburned powder coming out the muzzle.

 

[Perkiomen Bruce]

Related to a comment above about exposing more/less powder to oxygen. NOTE: Black powder does not require an external source of oxidizer. The formulation carries with it all the oxygen required.

 

[chorizo]

Related to a comment above about exposing more/less powder to oxygen. NOTE: Black powder does not require an external source of oxidizer. The formulation carries with it all the oxygen required.

You are correct. I meant that with the fine grades there is more surface area exposed and thus it burns more vigorously.

 

[Uncle Miltie]

I use fffgfor everything up to. 58 caliber rifled muskets.

Powder was milled finer in the old days than it is today.

The most accurate muzzleloaders ever made had barrels under 30" in length.

 

[Bad Karma]

Lots of different variables. I’ve been using 1-1/2F Swiss in my 45 caliber target rifles. 90 grains of the good stuff shows a 99% burn behind a 525 grain bullet. Nice to know but the important thing is that the rifles so loaded are capable and MOA accuracy much farther than I can see a bullseye.

 

[Abarnes]

It is the grind. More surface area exposed to oxygen and surface to burn.

Bore size makes a difference also as there is more room for expansion and thus more complete burn.

In short, volume of area to burn, the physical condition of what you are burning.

Faster burn mean quicker and higher pressure peak with resulting increase in velocity

Add heavier bullet weight and the increase of static inertia to overcome results in a smaller space to burn and a resultant increase in pressure and velocity.

@Brazos John Play with this calculator: Look at pressure peak, barrel lengths, grind and volume (caliber) and you will get a feel for what I mean

https://www.p-max.uk/cgi-bin/black_powder.cgi
On powder:

Black powder​

Main article: Gunpowder
Gunpowder (Black powder) is a finely ground, pressed and granulated mechanical pyrotechnic mixture of sulfur, charcoal, and potassium nitrate or sodium nitrate. It can be produced in a range of grain sizes. The size and shape of the grains can increase or decrease the relative surface area, and change the burning rate significantly. The burning rate of black powder is relatively insensitive to pressure, meaning it will burn quickly and predictably even without confinement,[12] making it also suitable for use as a low explosive. It has a very slow decomposition rate, and therefore a very low brisance. It is not, in the strictest sense of the term, an explosive, but a "deflagrant", as it does not detonate but decomposes by deflagration due to its subsonic mechanism of flame-front propagation.

That's a fun calculator, I wonder how accurate it is.

 

[longcruise]

That's a fun calculator, I wonder how accurate it is.

I have my doubts.

 

[chorizo]

And I do not. I have validated over 100 different loads for velocity using a chrono and it is spot on

 

[dave951]

It is the grind. More surface area exposed to oxygen and surface to burn.

Bore size makes a difference also as there is more room for expansion and thus more complete burn.

In short, volume of area to burn, the physical condition of what you are burning.

Faster burn mean quicker and higher pressure peak with resulting increase in velocity

Add heavier bullet weight and the increase of static inertia to overcome results in a smaller space to burn and a resultant increase in pressure and velocity.

@Brazos John Play with this calculator: Look at pressure peak, barrel lengths, grind and volume (caliber) and you will get a feel for what I mean

https://www.p-max.uk/cgi-bin/black_powder.cgi
On powder:

Black powder​

Main article: Gunpowder
Gunpowder (Black powder) is a finely ground, pressed and granulated mechanical pyrotechnic mixture of sulfur, charcoal, and potassium nitrate or sodium nitrate. It can be produced in a range of grain sizes. The size and shape of the grains can increase or decrease the relative surface area, and change the burning rate significantly. The burning rate of black powder is relatively insensitive to pressure, meaning it will burn quickly and predictably even without confinement,[12] making it also suitable for use as a low explosive. It has a very slow decomposition rate, and therefore a very low brisance. It is not, in the strictest sense of the term, an explosive, but a "deflagrant", as it does not detonate but decomposes by deflagration due to its subsonic mechanism of flame-front propagation.

Finally somebody else with the same information I've been talking about. Black powder has ONE burn rate and only the shape/size of the individual grains control the "burn rate" by surface area exposure.

Thanks @chorizo for this link!

 

[French Colonial]

I use fffgfor everything up to. 58 caliber rifled muskets.

Powder was milled finer in the old days than it is today.

The most accurate muzzleloaders ever made had barrels under 30" in length.

The most accurate muzzleloaders ever made had barrels under 30" in length.

And what muzzleloaders would you be refering to?