I guess the younger gen didn't learn about weights and measurements in grade school. We learned it way back in country school days.
The grain is from the avoirdupois system of weights and measurements that was a British system from before Henry the VIII's time, and is used in US still today. It's one of the smallest measurements in our system. (grains, ounces, pounds, tons and etc). (Not Metric)
The “grain” also happens to be the same in avoirdupois, troy, and apothecaries UNITS OF MASS.
The measures we use for our powder are volume measures. Period!! They can be used to measure the volume of anything you might put in them. The Words (Powder Measure) are used to sell the measure to a specific croud. All of you. But the measure itself has nothing at all to do with the weight of Black Powder.
These volume measures we use for our powder are used and marked the same way that our cup and oz's are.
1 cup = 8 oz. or 3500 grains.
Now it doesn't take to much to realize that 1 cup of feathers won't weigh 8 oz. Or 1 cup of lead won't weigh 8 0z. But they will both ocupy the same space.
The same thing goes for our powder measure. I could set it at 100 grains and fill it with ground feathers or lead bb's and neither will even come close to 100 grains because both have greatly different densities. But again they will both ocupy the same space.
So being a person can put things of different densitys such as above in the measures, What standard was used to make them? For sure it wasn't lead or feathers, or gun powder for it all has different densities as well.
WATER!! It is the only substance in the world that always has the same density since the beginning of time and anywhere in the world.
The weight of distilled water at the temperature of 62 Fahrenheit the barometer being at thirty inches Is the standard used by the world. This includes US and metric measurements.
To make a 1 cup measure you would weigh out 8 oz. distilled water or 3500 grains if you like then make your container hold that amount. Mark the measure 8 oz. or 1 cup
To make a 100 grain powder measure weigh out 100 grains of distilled water and make your measure hold that amount. Mark the measure 100 gr.
The measure above was made for our system but it could be made with metric marks on them too. water weighed the same but metric weights. milligram, drams or cc if you like.
distilled water weight is also used to make Our gallon and all our other weights and measurements. Even our bushell.
This water standard makes all volume measures to be the same anywhere in the world.
The reason we use a volume measure for black powder is that it is the only way to compare powders performance between brands or even lots from the same brand. Velocities, fowling, pressures and etc.
It is also the only way to acurately write down or tell someone how much powder a certian case will take to seat the bullet properly. If we used weights every brand of powder might sit at different heights in the case because of density, moisture content or ingredients used to make it. It would also be useless to compare different powders by a certian weight.
Someone here posted the advertised weight of a cartridge powder from way back. And said there was now way to get that amount in a modern case. But that weight was only for that specific powder at that time. Powder company's have always experimented with densities, moisture content and even ingredients so there would be no way to compare then to now. If those company's would have printed volume instead of grain weight on their box we would be able to compare.
(The “grain” is the same in avoirdupois, troy, and apothecaries units of mass.)
1 grain = 1/7,000 pound = 1/437.5 ounce
1 dram = 1/256 pound = 1/16 ounce
16 drams = 1 ounce or 437½ grains
1 milligram = 0.015 grain
1 grain = 64.798 91 milligrams (exactly)
1 ounce, avoirdupois = 437.5 grains (exactly)
1 gram = 15.432 grains or 0.035 ounce, avoirdupois
1 pound, avoirdupois = 7000 grains (exactly) or 453.59237 grams (exactly) or 256 drams or 16 oz.
A quick simple google search found these.....
http://books.google.com/books?id=LH...is measurement, based on water weight&f=false
http://books.google.com/books?pg=PA...Cw&id=LHdMAAAAMAAJ&ots=0NUv6I10-Y&output=text
http://books.google.com/books?id=1K...ois measurement based on water weight&f=false