Standard Displacement of Black Powder Volumetric Grain?

[Greebe]

What is the standard displacement of a black powder volumetric grain? I ask this because I was planing to make some powder measures and didn't know if there was a way to calculate the volume say for 60Vgr. I read that there is apparently not such standard, but there must be some volume that the manufactures use to make their powder measures. Surely they are not all different from each other.

So lets say that I was going to make a 60 Vgr powder measure that had a 1/2" ID. How would I determine the approximate length. It would be nice to know that way I don't have to waste a lot of stock trying to guess at it.

Oh, I also just read that possibly one volumetric grain of BP is = to a 1 grain of water by volume. So if you filled up a 60 Vgr BP measure with water, the water would weight 60 grains on a scale. I will have to go check this to see if it is correct. If so it would be easy enough to calculate volume of a measure. I have no idea if this is true or not.

One last question. If a BP load calls for a measure in drams it is referring to weight. Do these also correspond to Volumertric measure?

Thanks,
Greebe

[Greebe]

Ok so I went out to the shop and looked at some data in one of my engineering books. Here is what I found out.

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.

Greebe

[Junior1942]

According to the Lee Precision web site and manual, the Volume Measure Density (VMD, the volume in cc of 1 grain of powder) of black FFG powder is .068. So if I'm looking for a circa 40 gr-by-volume load of FFG to shoot in my new Lyman Plains Pistol, which I am soon to shoot for the first time, I need to find a Lee dipper which will throw that charge. I'll go with either the Lee 2.7 cc or the 2.8 cc dipper.

2.7 / .068 = 39.7
2.8 / .068 = 41.17

I'll actually use Pyrodex P, but I'm not interested in its VMD or the VMD of FFFG black. I want whatever size container would throw ~40 grs of FFG black.

In your case, you want ~60 grs by volume so multiply .068 X 60.0 = 4.08 cc. You need to make a container which has a volume of ~4 cc.

PS: My 2.7 cc Lee dipper is a slightly melted and stretched 2.5 cc Lee dipper.

[Doc Highwall]

Junior gave you good information, it is also in the LEE manual. I can only add or suggest, that you make the cavity at a 1:1.618 ratio, diameter to depth with a large radius in the bottom.

[mooman76]

If you compare one manufacturers measure to another they will be slightly off Dixie Gunworks catalog has a list of cartridges and how much they hold by BP grains. 30-06 is 70gr, 30 carbine is 20 45 colt and 30-30 are both 32 38 special is 24gr and 45 acp is 28gr. There is a whole long list but I'm not going to print them all and these are some of the most common.

[Freightman]

Thank you Jr. I went and measured my home made BP and a 2.8 cc dipper was 40.4 g which isn't to far off what commercial is, thanks.

[Greebe]

--Junior. Thanks for the reply. Using cc's would give you the same as what I did, but then I would have to be set up for machining and measuring in the metric system which I am not. This is why I decided to use cubic inches. I am just not fond of the metric system, this is America after all. :razz:

--Doc. The Golden ratio eh? I will keep that in mind.

--Moo. Thanks for the info. That would be a handy thing to know. I am planning on turning a few of my own powder measures which is part of my overcomplicated findings.

Greebe

[Junior1942]

--Junior. Thanks for the reply. Using cc's would give you the same as what I did, but then I would have to be set up for machining and measuring in the metric system which I am not. This is why I decided to use cubic inches. I am just not fond of the metric system, this is America after all. :razz:

--Doc. The Golden ratio eh? I will keep that in mind.

--Moo. Thanks for the info. That would be a handy thing to know. I am planning on turning a few of my own powder measures which is part of my overcomplicated findings.

Greebe4.08 cc3 = 0.24897687590651 in3

[Greebe]

Here is my plan. I am going to make some powder measures out of 1/2" copper pipe and then solder in a brass plug with a lanyard ring for hanging it off of a pouch. The ID of 1/2" pipe is actually .540".

At this rate according to my formal above, I can find that I need a length of 1.05" which will give me 59.9 grains by volume. I was thinking of making a set of fixed volume powder measures for now. I think that for starters maybe make a 60,70, 80, 90 and perhaps add 100, 110, and 120 later.

I will post pictures in a new thread when I get some made up one of these days.

Greebe

[Greebe]

4.08 cc3 = 0.24897687590651 in3

Cool. That would be 2 grains heavier than my math, but I bet that is because I based a volumetric grain off of the old formula of one volumetric grain of BP being = to a 1 grain of water by volume. I believe that I read one of the old books online that this was for FFg? I wonder what the difference in volume would be for different grain sizes of BP? I checked two of my measures with my formula and they came out the same as what they weighed with actual powder. Have you weighted one of the Lee dippers to see if it weighs what they say? I would be curious to see what the results would be.

Thanks,
Greebe

[mooman76]

Pick up a Dixie catalog if you have a chance. Not only do they sell allot of good stuff, good reading in the back of the catalog. If you are off a grain or two, no big deal. Like everything guns, consistency is the key.

[Big Rack]

If you have a Lee dipper set just use it to check your measure they have BP on there powder measure slide, also Dixie has or had info on using cartriges for dippers with a list of what held what I think they suggested soldering on a coathanger handle.

[fouronesix]

Seems like lots of mathematical machinations to make simple BP measures. Get a piece of your brass tube and plug one end (with the type and length of plug you are going to use for all of them). Weigh 50 gr of FF blackpowder. Pour into tube. Take a 3/8" +/- wood dowel and put in tube until it contacts powder. Mark dowel. Weigh 60 gr, pour and mark, repeat process in 10 gr increments until you have gone as high as you are likely to go. Cut individual brass tube lengths according to marks on dowel. Plug tubes, mark each for FF gr weight and file/finish spout ends. Fini