Should the powder charge be equivalent to the caliber?

[Whughett]

That's a rule of thumb for a rifle starting load, not pistol. I don't think even a Ruger Old Army or Walker could hold 44gr!

The Walker will take close to 60 grains. The ROA 45 easy. With round balls conicals might be a different story.
I can and do put 40 grains of 3F in a Colt45 case for use in my conversion cylinders.

 

[Khufu]

I shoot a CVA derringer made from a kit, I have shot it a lot. I used to carry it when I lived in Utah to circumvent the NO FIREARMS signs that popped up in a few places since Utah law considers muzzleloaders to not be firearms. I used 20 gr of 4f powder and a .440 rb. they are intended to basically inject the ball into the target as accuracy is somewhat less that ideal much over 10 yards and you are starting to get shaky on a target smaller than a dinner plate. I'm not sure it would be all that effective in a self defense situation, but it seemed better than just a knife.

 

[sheriff john]

Do it make a difference in what type of projectile is used, or do you go by weight as the startin' point of load workup? Seeing info on "Ball" sizes, assuming that means a patched round ball.

 

[Flintlock]

It's a rule of thumb for a starting point.

Starting point for rifles, half that for pistols.

 

[TreeMan]

I’ve shot a .44 cap and ball revolver with a 3” barrel but the cylinder add another 1-1.5” to the barrel length. The maximum charge is about 35 grains when compressed, using FFFg you can hear the difference between 25 and 35 grains when it hits a steel target. 15 grains seem to be a very small load even for a 3” derringer, does the 1-1.5” extra barrel length of the revolver really make that much of a difference? I wounder where the sweet spot is, too much powder and you decrease the travel of the bullet (equivalent to a shorter barrel) but a too small charge won’t generate enough pressure too gain maximum velocity.

Searching for an answer I found this chart Black Powder Ballistics Looking at the .44 Remington with a 5.5 inch barrel (cylinder not include) the heaviest charge of 46 grains gave highest velocity. A 6.5-7” barrel is a significant difference compared to the 3” of the Philadelphia Derringer though.

Are you planning using this derringer for anything other than novelty plinking? In my 50 cal Kentucky pistol I only shoot 25 grains 3F in it for targets. In my Ruger old army I only use 20 grains 3F. That’s what is most accurate in both of them. I think whatever powder charge you use from 15 grains to 45 grains it’s just gonna be a noise maker and make smoke. Most likely won’t be shooting for groups past five to ten steps with a derringer. In my opinion anything over 20 grains of 3F in a derringer is just wasting powder.

 

[doubleset]

Not sure I could get 36 grains in my 1851 navy without a lot of exertion. But I know that if I did, I'd definitely notice the recoil.

 

[Grenadier1758]

I’ve read the powder charge can be determined by holding the bullet/ball in a cupped palm of one’s hand and pouring powder over until the ball is just covered.
Truth or fiction.
In shot shells, and perhaps muzzle loaders a square load is equal powder and shot by volume.

Truth or fiction? The answer will depend on application.

Here in the pistol and revolver forum, fiction.

In the rifle forum, this is a very imprecise load that there is a degree of truth in the method. I have used the pour the powder over the ball for loading my King's Musket and get pretty close to 90 grains with a wide tolerance. Nothing to use for a target load.

 

[Stantheman86]

No , that whole "match the charge to the caliber " is nonsense

My .69 Smoothbore uses 100 gr of 1f or 2f

My .54 Harper's Ferry pistol uses about a 30 gr charge of 3f

 

[david w]

No , that whole "match the charge to the caliber " is nonsense

My .69 Smoothbore uses 100 gr of 1f or 2f

My .54 Harper's Ferry pistol uses about a 30 gr charge of 3f

36 grains in my .36 is too much, and 62 grains in my .62 is too mild.

 

[toot]

Absolutely not. 15 gr. is all you need.

so true! 15 grs, is adequate for it. 45 grains, hold on to it. way to much! not me. good advise!

 

[Sparkitoff]

I have some original powder dippers. I don’t know the history of them but they are alleged to be from late 1700s to mid 1800s. Most of mine are English or European. What is interesting is that about 3/4 of them have something in common. The “cup” will hold one ball from the intended arm. The crest of the ball is even with the top of the cup. The cup is just wide enough for the ball to slip in to the bottom and fall out if you turn the cup. This is similar to the concept in smooth bore loading where you use the same cup for powder and shot. The powder and shot are volumetricly equal. I have more dippers than corresponding rifles or revolvers, so I can’t try them all. For example, my .454 ball fits just right in the cup intended for a pistol that size. That dipper holds 28 grains of Goex Fffg. I have one that holds a .530 ball and 56 grains of Fffg. The one that holds a .626 ball hold about 74 grains FFg. This is more than a coincidence and tells me a lot about what charge was being used in Edwardian and Victorian days. I’m not sure if this is across the board from pistols/revolvers to rifles and smoothbores.

 

[Versanaut]

Lots of good info here. I have a 4" 36 cal derringer. She takes 10 grains of 3Fg. Much less and the patched ball starts to interfere with the flashhole and I start to have missfires. (The flash hole is not quite at the very back of the breech).

 

[Whughett]

But nobodies mentioned that unlike smokeless powder cartridge loading, a black powder gun is at best an imprecise exercise. A full grain hardly matters one way or the other in a smoke pole. Do that in metallic loading and bad things can happen.

 

[doubleset]

Well, with the typical way of loading black powder, you don't even know what your weight difference is since you load explicitly by volume. So any talk about differences in grains is a bit goofy, and the whole "grain" value is at best approximate. With smokeless -- and even if you use volumetric methods to speed reloading -- you'd better be paying close attention to the precise weight of the charge you're throwing (and be checking the accuracy of your volumetric approach frequently). The black powder gun CAN be a precise exercise (and the bench rest guys and slug gun buys make it that), but for the average target or hunting shooter it's "Close enough is good enough" as long as you achieve uniformity.

 

[Greenjoytj]

All this brings up the manner in which black powder releases its energy. It’s an explosive which means it releases or burns up all its stored energy in one burst.
Smokeless powders burn at a controlled rate determined by the formulation and the coatings applied during manufacture. It depends on a pressure chamber to work. Black powder doesn’t.
An overly simplistic view probably more complex than that.

Black Powder doesn’t explode it burn at a very fast rate.
Black powder burn rate is controlled by the granulation size.
The granules burn on the surface into towards their center.
Finer granulations burn through faster because the granule is small. The flame front moves from one granule to the next quickly because the granules are very close to each other, even when their not compressed.
Compression improves the efficiency that the flame can travel to the next granule.

Large courser granulation takes longer to burn through to their center, this takes more time to burn completely so the total time until total conversion to gas is longer.
This is why course granulation powder makes more MV in a long rifle barrel, the slower start from lower start pressure but the longer burn time provides a longer push on the bullet as the flame converts more and more solid powder into gas ending in higher MV for the rifle.

2 volumes of powder of equal mass weight, one is fine the other is course, the total volume of gas produced when burnt will be the same for both powders. The fine powder will convert to gas reaching peak pressure first.
The course powder will reach the same peak pressure it will just take a little more time to get to peak pressure.

 

[david w]

Black Powder doesn’t explode it burn at a very fast rate.
Black powder burn rate is controlled by the granulation size.
The granules burn on the surface into towards their center.
Finer granulations burn through faster because the granule is small. The flame front moves from one granule to the next quickly because the granules are very close to each other, even when their not compressed.
Compression improves the efficiency that the flame can travel to the next granule.

Large courser granulation takes longer to burn through to their center, this takes more time to burn completely so the total time until total conversion to gas is longer.
This is why course granulation powder makes more MV in a long rifle barrel, the slower start from lower start pressure but the longer burn time provides a longer push on the bullet as the flame converts more and more solid powder into gas ending in higher MV for the rifle.

2 volumes of powder of equal mass weight, one is fine the other is course, the total volume of gas produced when burnt will be the same for both powders. The fine powder will convert to gas reaching peak pressure first.
The course powder will reach the same peak pressure it will just take a little more time to get to peak pressure.

Actually, black powder does explode, but with low pressure.

 

[Flintlock]

But nobodies mentioned that unlike smokeless powder cartridge loading, a black powder gun is at best an imprecise exercise. A full grain hardly matters one way or the other in a smoke pole. Do that in metallic loading and bad things can happen.

But nobody would mention it because it's not part of the topic.

 

[smoothshooter]

I’ve heard that pistols/revolvers should be loaded with grains equivalent to roundball caliber for optimal performance, like 30 grains for a .30 cal, 45 grains for a .45 cal, etc. Is this true? I’m looking to buy a Philadelphia Derringer in .45, it has a 3” barrel. I’ve never shot a BP pistol with such a short barrel before. Can I load it with 45 grains of powder?

The one grain of powder per caliber is an old rule of thumb as a starting point for rifles only.
If you put 45 grains of powder in your derringer it will not likely all burn within the confines of the barrel.

 

[morehops52]

That's a rule of thumb for a rifle starting load, not pistol. I don't think even a Ruger Old Army or Walker could hold 44gr!

A full charge is 40gr in my ROA 45.

 

[stephenprops1]

I restored a 45 caliber Dikar, Spanish percussion pistol a few years ago. I shoot 15 grains of FFF in it, with a 440 or 445 patched round ball. It still shoots a little high. I tried 20 grains and had significant recoil.