Topic: Is a grain really a volume measure?
Retrieved: 12/20/2014
Last Post: 01/08/2007
I've been loading my BP by filling my cases until the bullet compresses the powder by about 1/16 of an inch. No air space, just a little compression. I understand that different powders weigh differently - especially betwee ffg and fffg - and also brands - and that is why I can not rely upon my scales to measure powder. EVERY reference I have read has always said in bold print these powder loads are by grains volume not weight. So, trying to understand this I have asked a number of engineer friends "how do I measure by grains in volume?" In summary, the answer I get has to do with crystal size, density of material... etc. and the grains-volume is calculated after one knows the weight of the material and the shape of the material one wants to measure (to see a more detailed answer that closely parallels engineering speak see MMTA-9812-3081F.pdf
[link 404; no file of that name found via Google]
At my understanding level, volume is three dimensional that includes height, width and depth: things like cc (cubic centimeter) are volume - grains are not defined by height, width or depth. Grains are defined by density of material times volume. So, how can ALL references refer to grains as the unit of volume to load BP with - yet, never give one a conversion?
I know I'm dense - please help enlighten me.
Carolina Sorillo
December 27, 2006
I am by no means an expert on anything. But a cap-n-ball flask with a 24gr. spout throws a charge of FFFg Holy Black that weighs 24gr. So to answer your question a grain is a measure of weight.
I have no idea how to do the 'rithmatic to come up with this volume to grain measurement, and quite frankly I don't wanna know. As long as I got enough powder in the case to get the desired amount of compression for good fire and smoke or enough powder in my C-n-B's to get a good blast of fire and smoke, I am as happy as a Tornado in a Trailer Park.
Ranch 13
December 27, 2006
Grain is a unit of weight measurement in this instance. Just like ounces only smaller.
If you were to weigh your charge of bp then you could come up with an average of "x" grains, and then continue to charge your cases and say you shoot a load of "x"grains by volume. Even the volumetric powder measures like the ones used with muzzleloaders are calibrated to throw a charge that will weigh very close to the stated grains.
Most all of the established data (meaning stuff gathered from places other than internet) say that the black powder charges are measured in grains weight. I still maintain there's a huge amount of confussion brought about by the introduction of Pyrodex, which was designed to be used on a volume basis in place of bp. A measure that would throw 70 grs of bp will throw a charge of pyrodex that actually weighs about 56 grs. Supposedly that charge of pyrodex would equal ballistically the 70 gr of bp. Its been a mass confused mess over weight vs volume every since.
John Boy
December 28, 2006
Ranch... Hear! Hear! or is it Here, Here! Good Words.
PS: Don't for about about H777 by volume too.
TAKAHO KID
December 28, 2006
Yes various powders vary in density from grain size to grain size as well as from manufacturer to manufacture and even lot to lot. (This drives the BPCR shooters nuts!)This will cause changes in weight vs volumn. In other words, if I throw a charge of 70 grains (by weight) of 2F Swiss which is a dense powder it won't fill the case as much as 70 grains of say 2F Goex which is less dense.To get the desired compression you would simply increase or decrease the weight of the charge thrown.
However, I know that by measuring out my powder by weight rather than volumn my charges will be nearly exact from cartridge to cartridge. With a volumn measure such as a scoop there are several variables. How fast did I drop tube it? Was I consistent from cartridge to cartridge? If I am scooping it did I level off the scoop exactly the same?
Ultimatly it is indeed volumn we are concerned with i.e. how full is the case and thus how much compression are we getting. The ultimate goal is to have that volumn be identical from case to case.
Also, and this ONLY APPLIES TO REAL BLACK POWDERloading data is ambiguous. Don't get hung up on using exactly the charge specified. One of the amazing things about black powder is its flexability. For instance, in my guns at least, I have found that Swiss works better with little to no compression while GOEX I have had to compress the @%#& out of it. What this means is that even though the recipie may call for 68 grains of powder I may only use 65 grains of Swiss or perhaps a full 70 for GOEX and even that may vary from lot to lot. Its what the gun likes that counts. Thats the wonderfull thing with BP - the ability to fine tune it without risking life and limb unless your doing something way of the wall.
Reverend P. Babcock Chase
December 28, 2006
Here's an over simplified explanation.
"Grain" indicates a weight as in on a scale.
Muzzleloaders (7 other Black Powder shooters) used "Volume" measures to load their guns. These measures were crafted so that, when full, they held a specific weight of black powder. Naturally as the brand or granule size of the black powder changes the actual weight of the charge varied slightly.
Given the forgiving nature of Black Powder the slight changes did not affect things too much.
As you may have read here on The Open Range, once folks start loading cartridges things like case capacity, compression, lubes, wads, bullet length, crimping, etc. add All kinds of variables. Smarter folks than I can carry the ball on BP Cartridge loading, but for now "grains by volume" means a measure that, when full, holds a certain weight of Black Powder.
There, a complete mastery of the obvious.
Ranch 13
December 28, 2006
Thanks John Boy.
Takaho you bring up a good point, a half grain of bp one way or the other isn't likely to have as much dramatic affect as it would in smokeless.
Dutch Bill
December 29, 2006
For what it is worth.
I have been using a 35 year old Treso brass adjustable powder measure as my "standard" in loading ml guns. Used it in all of my powder work.
Back before I retired and had a real job in a chemical plant laboratory I took the measure into the lab. Sealed the plunger when it was down at the bottom of the measure. Then calibrated it with distilled water with 2 drops of alcohol to kill the water's surface tension.
Looking at the volume of the measure and the weight of the water it would "throw" it appeared that the measure followed the idea that in any weight to volume relationship water is is as 1. In the metric system one ml of water will weigh 1 gram.
The explosives industry measures the apparent, or bulking, density of granular propellant powders in grams per cubic centimeter. They report the loading density of various types of black powder in g/cc.
Going back into du Pont black powder production I found that the loading density gave just about 100 grains weight of powder from the measure at the 100 grains (volume) setting. If you gently bumped the measure to settle the powder in the measure while filling it. If the measure was not bumped the data would be about 5 to 10% lower than the settled data. All of the military tests dealing with the loading density of black powder calls for settling the powder in the measure.
Different brands of black powder, and even different lots within a brand, will give different loading densities.
The first shipment of KIK into the U.S. in 2000 gave a loading density of around 0.90 g/cc. In other words if you poured the powder into my measure set at 100 grains volume the actual weight would have been around 90 grains.
Looking at GOEX production I found that the various lots of powder ranged from 0.99 g/cc to 1.05 g/cc. Swiss runs up around 1.08 to 1.10 g/cc.
Each powder manufacturer has their own specific powder density range that they work in.
Measuring black powder in volume grains is an arbitrary method of measurement. Once you understand how the system works you don't get too excited over the differences you sometimes see.
wayne
January 01, 2007
Using a certain volume of blackpowder,I'd imagine, goes back to the days when there were only muzzleloaders. People found the acceptable load that shot well in the rifles or pistols and used a container that held that amount of powder to load the same each time. What I'm getting at is the fact that volume comes into play simply because people couldn't carry around scales to measure their powder. Well... to me staying within a manufactures recommended range of powder max and just finding the best most accurate powder load fer the gun and duplicating that each time loading is the important thing. If a person wants to weigh it to duplicate it with a scale then that's fine for them. More consistant that way.
Anyway it doesn't have to be made confusing comparing volume to weight. Volume is just a certain weight of powder that is duplicated in the field with a powder measure since carrying around a scale is not practicle. Thankfully blackpowder isn't as touchy as smokeless when it comes to powder amounts. A coupla grains one way or the other makes only a small difference with blackpowder. It does make a difference though. It depends on what kind of shooting you'll be doing whether or not that difference makes any difference. Anywhooo... I think the most consistant way to measure powder is by weight and a scale. In the field you try to duplicate that weight by using a powder measure that uses volume that's set to throw the certain weight you calculated on the scale. Weigh the powder and put it in the volume powder measure and set it to top off with that weight of powder. Settling the powder is a good idea but... just settle or not settle the same everytime. Anywhooo... whether powder weighs a certain amount in grams or whatever ect.ect. means little because the standard emulates and starts at the "gun" with the powder charge that makes it shoot the best. (within manufacturers recommendations) Just find the weight or volume that works the best and duplicate it the same each loading.
Jorge Guapo
January 01, 2007
Thanks for the replies. We all seem to agree that volume is the more accurate measure for loading - especially if one uses more that one brand or batch of powder. I wonder why we don't just take Richard Lee's advice and just measure and communicate by cc? It would sure take any possible miscommunication out of the equation.
Driftwood Johnson
January 03, 2007
Quote
I wonder why we don't just take Richard Lee's advice and just measure and
communicate by cc? It would sure take any possible miscommunication out of
the equation.
Howdy
Actually, I have been doing just that for years. For my CAS loads, I use Lee dippers as my base line data. The Lee dippers are still labeled with CC, even though the rest of the world changed to Milli Liters years ago. But 1CC=1Milli Liter, so the data is the same, even though the labels have changed. Since I am portioning out my powder by volume, it just makes sense to me to use an internationally recognized unit of volume. I could just as well be using Cubic Inches for my base line data, but I don't have any dippers labeled in cubic inches.
Most of my BP cartridge shooting has been confined to Goex and Elephant. When loading for CAS, I try to keep things simple, and choose a powder charge based on my set of dippers that will give me the appropriate amount of compression I want for any particular bullet. If 2.2CC of powder is not quite enough for good compression for a particular bullet, I'll jump up to the next dipper, which is 2.5CC. I don't sweat it trying to find exactly 2.4CC. My experience has shown me that the volumes available with the Lee dippers give me plenty of leeway for CAS loads.
I keep a chart in my loading notebook that gives the grain weight for any of the Lee dippers that I commonly use, cross referenced against the particular brand and powder granulation. For instance, off the top of my head I know that 2.2CC of Goex FFg will weigh out to 34.5 grains, while 2.2CC of Elephant FFg will weigh out to 37.5 grains. I arrive at these figures by dipping out 10 level charges and dividing by 10 to get an average.
Armed with this information, I know that my favorite load for 45 Colt under a 250 grain PRS bullet is 2.2CC(aproxx. 34.5 grains) of Goex FFg. This is the way I usually express the data, specifying the volume of the powder, and only listing the weight as an approximation, since it can vary from lot to lot. Also, keeping the volume figure constant, I will achieve the same amount of compression from load to load, even though I may be varying the actual weight of the powder charge slightly as I use powder from different lots. If I change over to Elephant powder for a while, I fully realize that I will be adding more powder by weight to my charges. But for CAS ammo, I am not really too concerned about that, I want to attempt to keep my compression consistant from load to load.
Now that I am using a Lyman powder measure, I am still using the same data, having set the measure to equal my favorite 2.2CC powder charge.
Now that my Elephant powder is all gone, I just got my hands on 5 pounds of Scheutzen. It will be interesting to go through the data for this new (to me) powder.
That's how i do it for my CAS loads. 45-70 long range is a different story.
Delmonico
January 04, 2007
To make it easier to understand a grain is 1/7000th of a pound or 1/437.5th of an ounce.
Rye Miles
January 05, 2007
Howdy Delmonico, so it's safe to say there's 7000 grains in a pound and if'n I use 35 grains in a .44-40 I should get 200 rounds outta a pound?
(Boy am I a rocket scientist or what?
Delmonico
January 05, 2007
Naw, I bet you used one a them 'lectronic cipherin' machines. However with enough black powder one could pretend to be a rocket scientist. I had this gread idea one time, my brother broke the nock off one a them hollow 'luminum arrows and I had a can of FFg. He would not let me have the arrow, said if a arrow shootin' flame would have impaled itself in one of the neighbors Holsteins him and I would have been the prime suspects.
Four-Eyed Buck
January 06, 2007
Guess I'll chime in here. volume in grains is an English measure. It based on barley corns. Out of the seeds that nature has given us, the barley corn is the most uniform from piece to piece. So their volumetric measure setup means this container or whatever will hold or has the volume to hold X amount of barley corns/grains. This is where the term grains comes from. BP is measured in volume, hence in the english system, grains... Buck
Driftwood Johnson
January 08, 2007
Quote
Howdy Delmonico, so it's safe to say there's 7000 grains in a pound and
if'n I use 35 grains in a .44-40 I should get 200 rounds outta a pound?
Yup, it's that simple. However if you read my preceding remarks, you may find that 35 grains of powder 'X' takes up a different amount of space in the case than pwder 'Y'. So you may or may not achieve the compression you want.
Quote
Guess I'll chime in here. volume in grains is an English measure.
have to respectfully dissagree with you Buck. Sources dissagree on how far the grain goes back as a unit of measure. Some say it goes back to the Egyptians. But even when they were using a grain of Barleycorn as a unit of measure, the English used it as a unit of weight, not volume.
http://home.clara.net/brianp/weights.html
Sir Charles deMoutonBlack
January 08, 2007
There is a relationship between volume and weight, but it is "one to one" usually only for water under specific conditions. In American schools do they still teach the mantra A PINT'S A POUND THE WORLD AROUND? In the metric system that is in universal use, except for one country that refuses to adapt (who's name I can't come up with!), there is a direct relationship between the weight, or "mass' of water and it's volume. One kilogram of water has a volume of one litre; - it's very simple, ya'all!
A KILO IS A LITRE THE WORLD AROUND, if you will, of water that is!
As it applies to powder, the relationship depends on the density of the powder. A given weight of a given powder can be contained in a measure of a given volume. If the powder is changed, the assigned volume will not likely result in the same weight. Of more importance in loading black powder cartridges is the volume, as you will have observed in loading them or reading about loading them.
How you RECORD the amount of powder you require for a given load, with a given powder is your choice. Some use the same measure as before (i.e. Lee scoop 3.1cc) to get the same loading density, and others, usually those who weigh their loads as part of their loading routine, prefer to record the weight of the chosen charge of differing powders.
Is all of this as clear as mud? BTW, i've read of 19th century ML target shooters who adopted very specific rituals in pouring powder into their measure. (Shake the can three times with a specific motion, and pour just "so".) When pouring into a measure, be just as careful to do it exactly the same way each time, and level it exactly the same way, and then shake/pour the powder into your drop-tube exactly the same way each time, or you will get different amounts of powder in your cases each time! Because it is granular, it is capable of "settling" into different volumes.
To answer the initial question, "grain' is a measure of WEIGHT!
Didn't those old Saxon kings use those same barley grains to standardize the inch?
Delmonico
January 08, 2007
BTW that water has to be pure, dissolved items such as salt or iron will change it slightly, but that is cuttin' it awful close.