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Volume of powder

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Col. Batguano

75 Cal.
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I know we shoot our loads by volume. which is also pretty close to weight for FFg) but does anybody know how much ACTUAL volume (or maybe the correct term is displacement?) a normally loaded and compressed load takes up?? I'm trying to figure out what the actual minimum load I could load would be and still fully cover a vent liner.

Of course, it will vary by caliber as to powder height, but the volume of a compressed 10 gr. load would send me on my merry way. I can do the calculations from there.
 
I've checked my comercial volume measures with a scale with powders from 1 1/2fg though 4ffffg, and they are always very close to being correct to the scale numbers.

I use my 54cal flint rifle for snowshoeing in the winter and I try to put a ball into ever target that stands out to me, as I trudge throught the snow.

My load is 15gr of 3fff with a RB and a light patch. It's quiet and I don't ring my ears. With this load my rifle will "plug-up" after 10 shots or so....so them I load a few 120gr+ loads and it blows the carbon build-up out nicely.

I just measured my measure with 10gr volume it is .270 deep x .435 dia.. And I tried 10gr of 3fffg with my .69 Tower pistol and the .600 ball pathed with old towel...it shot right out no problem.
 
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I poked around some other places and found that it is roughly equal in displacement and weight to water. Answered my own question.

The weight of water equals 62.4 lbs for a cubic foot. This works out to 998.4 ounces.

We can take the weight and divide it by the cubic inches (1728 cubic inches in a cubic foot) to find what a cubic inch weighs.

So 1 cubic inch of water weighs .5777777778 ounces

1 ounce = 437.5 grains. Thus 1 cubic inch of water weighs 252.7777778 grains (.5777777778 ounces * 437.5)

volume = Pi * radius2 * length

So lets put this into action.

If we have a cylinder that is .39" in diameter and 2" long first we find the volume.

V=3.14*.195(sq)*2 = .238797 cubic inches

So .238797 cubic inches * weight of one cubic inch in grains(252.7777778) = 60.36grains of water by weight.

I checked this with a powder measure and it works out to be within a grain or two of the math.

There you have it. A black powder volumetric measure is based on the weight of water.

So one volumetric grain is = to one grain of water.
 
For reference here is a volume (in cc or cubic centimeter) to BP weight chart for the Lee Precision ‘Dipper’ Powder Measure Kit. I find the dippers quite useful for quickly measuring out various loads of powder and/or shot.
upload_2020-1-15_16-35-46.jpeg
 
For reference here is a volume (in cc or cubic centimeter) to BP weight chart for the Lee Precision ‘Dipper’ Powder Measure Kit. I find the dippers quite useful for quickly measuring out various loads of powder and/or shot.
View attachment 22273
Richard Lee was WAY ahead of the curve with loads and reloading, black AND smokeless. In years past I had the opportunity to speak with him several times. He also pioneered the lead hardness chart with PRESSURE, not velocity. His data has held fast and been proven for 4 decades now. Yet the argument for lead hardness vs velocity still rages, but does not pass the test of proof. The chart is in the 2nd edition of his reloading book. PRICELESS. That same reloading book has a ton of data on black powder reloading.
 
You could do the math, Or you could measure from the end of your barrel to your vent liner, mark your ramrod and pour in powder and compress to aprox. seating pressure until the mark is above the end of the barrel. Keep track of how much powder you pour in. Probably have to put a ball on top and shoot it out, or just shoot it out without the ball.
 
Taking this a step further to figure out the minimum load (by volume) that will cover a 1/4" vent liner with the rear of it placed .05" above the breech plug, or, .30" total height;

Caliber Minimum charge
32 ...... 7.18
36 ...... 9.26
38 ...... 10.41
40 ...... 11.64
45 ...... 15.07
50 ...... 19.02
54 ...... 22.57
58 ...... 26.49
62 ...... 30.78
69 ...... 39.22
75 ...... 47.46

This table assumes the bottom of the ball is level with the top of the vent liner and the charge fills in around the bottom of the ball as the ball & patch are loaded down in and on top of it.

I didn't want to mess around with the differential volumes of the different kinds of rifling, or the volume of the cone of the vent liner, so just assumed a smooth cylinder. Don't these volumes and minimum loads make intuitive sense though?

Ain't math fun some times?
 
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I know we shoot our loads by volume. which is also pretty close to weight for FFg) but does anybody know how much ACTUAL volume (or maybe the correct term is displacement?) a normally loaded and compressed load takes up?? I'm trying to figure out what the actual minimum load I could load would be and still fully cover a vent liner.

Of course, it will vary by caliber as to powder height, but the volume of a compressed 10 gr. load would send me on my merry way. I can do the calculations from there.

But the powder can appears to be of a 1 quart size. (32 ounces to the quart of water.) 32 x 437.5 = 14000
It should be 7000 to be equal.

So the value is doubled, not equal to water.


Which one of us is drunk?

Zonie we need some Math help.
 
Caliber Minimum charge
62cal ...... 30.78gr


This table assumes the bottom of the ball is level with the top of the vent liner and the charge fills in around the bottom of the ball as the ball & patch are loaded down in and on top of it.

I'm sure no one else has ever done this,..LOL but while hunting in the backcountry, I dry-balled my 62cal smoothie. Sat down and started working powder through the touch hole. After a while I triggered her and the ball left with a nice sounding "SNAP(!)".. sure wasn't no 31 grains in her.

In theory a round ball setting on the bottom of an empty barrel should still have room for powder from the balls' pole, up to its' equator. Assuming the breech plug face was flat and a wad was not used.
 
Indeed you are both correct. If the ball is sitting just kissing the plug face, there would be that space between that and the "equator of the ball, or the radius. If your "equator is lower than the bottom of the cone of the touch hole you won'd be able to get powder in there. That amount of room / powder would be as per below... I left that out of the above table because I figured guys would be most interested in the bottom line as I laid it out.;

32......1.08
36......1.54
38......1.81
40......2.11
45......3.01
50......4.13
54......5.21
58......6.45
62......7.88
69......10.86
75......13.95
 
Indeed you are both correct. If the ball is sitting just kissing the plug face, there would be that space between that and the "equator of the ball, or the radius. If your "equator is lower than the bottom of the cone of the touch hole you won'd be able to get powder in there. That amount of room / powder would be as per below... I left that out of the above table because I figured guys would be most interested in the bottom line as I laid it out.;

32......1.08
36......1.54
38......1.81
40......2.11
45......3.01
50......4.13
54......5.21
58......6.45
62......7.88
69......10.86
75......13.95

Now those look closer to numbers I've used.
 
Quotitgh deer my insides were wrecked by ballistic co efficient and corleis effect
With me said the coon I’m a hat on his head
‘Cause I simply forgot about fine alloyed lead’
And legions of Brits in their red coats and gear all shook their heads and agreed with the deer
‘twas not skill or bad luck we encountered deaths path but simply because the guy knew his math’
Mathematics is fine but don’t leave out a trifle
Like the head eyes and hands that back up the rifle”
I know nought who wrote the poem I read in in the buck skin journal years ago, and those are just the parts I remember.
 
But the powder can appears to be of a 1 quart size. (32 ounces to the quart of water.) 32 x 437.5 = 14000
It should be 7000 to be equal.

So the value is doubled, not equal to water.


Which one of us is drunk?

Zonie we need some Math help.
I think your first problem is you say the powder can appears to be of a 1 quart size. It's not. It is closer to a 1 pint size.

If it is a 1 pint size it would hold 16 ounces so we would have 16 X 437.5 grains = 7000 grains.
 
The original purpose of the thread was to figure out what a reasonable minimum load might be that would reliably provide a decent chance of ignition. While in theory (as per above) a 4.13 gr. charge of powder in a 50 cal might be a theoretical minimum for a deliberate load, (for a flint gun with a TH) I think it'd be a pretty silly one. Accuracy certainly wouldn't be optimum either.

To that end, that's why I would regard the first chart, showing a 19.02 gr. charge as the lightest PRACTICAL deliberate minimum (for a 50). Even at that, a coned liner is still going to put a portion of the cone above the tangent line of the bottom portion of the ball.

I think minimum loads are useful, particularly when introducing newcomers to firearms in general, and BP in specific. Less noise. Less recoil. Knowing that number is helpful in that end. Note; BSA recommends a 30 gr. charge as a starter load (in a 50). Only cap or in-line guns are allowed in their program.

I've read plenty of posts from guys that are shooting 10 gr. loads in their 32's. I wanted to find out how close to the minimum that load actually is. According to the calculations, it's a little less than 3 gr. above it. In that case, they may have close to the same amount of powder in the pan as they have under the ball!
 
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I think your first problem is you say the powder can appears to be of a 1 quart size. It's not. It is closer to a 1 pint size.

If it is a 1 pint size it would hold 16 ounces so we would have 16 X 437.5 grains = 7000 grains.

Now you're going to make me go measure the liquid volume of an empty can aren't you?
 
I measured a can, it holds 28 ounces. If I recall correctly, they are filled with Pyrodex to the about the 24 ounce mark (by volume of water).

So if we take 24 X 437.5 = 10500
or, 1.5 times the volume.

Still not a 1:1 ratio, but I don't have a brand new full can to be sure of the fill level.
Another full cup of volume would need to be removed to be equal.

Anyone have a new can full ?
 
If it was a Pyrodex bottle or can, they are intentionally made larger than a real black powder can. They have to be because Pyrodex is about 30 percent less dense than real black powder and a Pyrodex can/bottle holds one full pound of the stuff.

I just measured a GOEX 1 pound can and find the volume of it calculates to be about 34 cubic inches.

If real black powder weighs about 252 grains per cubic inch (which I think it does), that can would hold 8568 grains of powder. Filled to the top, that would be 1.22 pounds of powder but remember, they don't fill these one pound of black powder cans up to the top. There is always some distance from the top of the powder up to the top of a new can when you open it.
 
Ok, I'm not going to measure an old Goex can. What if we weigh 1 fluid ounce (volume) of powder and see if it weighs 1 ounce.

P.S. I thought Pyrodex was a 1:1 volume equivalent to black powder. It is less dense, but more energetic .
 
I was looking to reduce the powder load in a plains pistol and ended up with the "dry ball" because of the patented breach, I found the hard way, don't go below a certain load.
 
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