Jim Watson
Member
That's about right, the fakes run about 78% the density of real black.
CC's to Grains
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BCRider
Member
And that would be... BINGO! And just to lead to future confusion in the eventual internet age they marked them as "xx grains".... leading us newbies and easily confused folks to think that there's a mystical "volumetric grains" standard of measurement that doesn't really officially exist. And I was in the same club until the last long thread on this same topic.
And as you found with measuring out and weighing the products there are slight differences. But consider too that there are significant differences simply due to how the powders heap on top or if you shake the measure while pouring and cause the powders to settle.
So what we have with our fixed or adjustable powder measures that are marked in "grains" is a roughly approximate measure that is SUPPOSED to drop that same weight when using traditional black powder. The volume measure is not, technically speaking, an accurate one. It's a measure used for convenience since it was hard for the mountain man or other muzzle loading hunter to carry out a beam balance to measure the charge out by weight.
The weight won't always match up of course. As you say there are the different granulations of black powder and the substitutes. But it ends up being "close enough" for field work or general plinking when you're working with the bulkiness of the black powder charges.
But if you're getting into some serious shooting such as kwhi43 mentioned a few posts back then you set aside your convenient "weight equivalent" volume measures and use a real scale to weigh every charge.
The one thing that throws this off for me is that Pyrodex is supposed to be used as a direct replacement (grain for grain) for regular BP. As we see in my case real BP weighed much more than Pyrodex. And so it seems it needs to be measured by volume and not by weight. Right?
Would you happen to know the thread of which you speak of BC?
Would you happen to know the thread of which you speak of BC?
You can disagree all you want, but the vast, vast majority of black powder shooters understand and use this bogus concept successfully, and have for many years. What's truly bogus is the constant whining that it doesn't exist. Sorry, but it does exist, traceable to the NBS or not.
Exactly, to five decimal places? No. Within a couple percent, yes.
No. 150 years ago they did what we should do today: found a charge that worked for them using the specific gun they owned and then used that same volume every time. Usually they fabricated a measuring device from a hollow antler or branch of wood.
By volume, not by weight. 50 grains/volume of Pyrodex P should give you close to the same performance as 50 grains/volume of 3f real black powder. Oh, but wait, that unit of measure (grains/volume) doesn't exist, so you can't do that. Guess you'll just have to calculate the weight of Pydrodex P that gives the same performance as 50 grains/weight of 3f real black powder.
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Kernel
Member
Grains volume, unless stated otherwise, is assumed to be based on H2O (water) as the standard. One cc of water weights 15.432 grains. By coincident, pretty close to what a cc of black powder weighs. On the Lee Precision VMD chart water would be 0.06480 cc/grain.
http://leeprecision.com/cgi-data/instruct/VMD.pdf
When Homer Powley developed his now famous Powley Computer he used the “grains volume” of 252.4 grains (H2O) per cubic inch. A value that is present in a number the equations. The Powley Computer doesn’t use cubic centimeters or any metric units.
http://leeprecision.com/cgi-data/instruct/VMD.pdf
When Homer Powley developed his now famous Powley Computer he used the “grains volume” of 252.4 grains (H2O) per cubic inch. A value that is present in a number the equations. The Powley Computer doesn’t use cubic centimeters or any metric units.
Pancho
Member
historically speaking our fore-fathers had no way of measuring by weight a powder charge in the field. Gunmakers, knowing this lack of technology offered their customers volume containers found suitable for the firearm made and sold. Grains by weight were crudely converted to volume via the dipper method to accommodate the rural riflemen that would never see a scale again. Giving them the lke terms of grains(weight measurement0 vs. volume measurement gives us all time to pause. especially now when we are presented with multiple choices of reproduction [pwders/
Noz
Member
This concern, volume/weight, has been going on long before I became involved in black powder.
This is one of those things that you accept "because".
Because what?
Because long ago a fella weighted a pile of black powder. I't weighed X grains.
He poured it into a brass tube and scratched the tube at the top of the powder. That volume became X grains of black powder.
Since black powder is a relatively low order explosive (my term), a slight difference in powder charge makes virtually no difference in the velocity of the projectile.
Therefore his measurement is good enough for daily use.
If you are going to shoot 1000 yards all day then you probably need to weigh each charge. The same would apply to the bullseye shooter.
BUT for us regular guys that arte shooting a piece of steel or need one minute of deer accuracy the volumetric powder measure is good enough.
Just a side note. I have 5 volumetric black powder measures. There is a consistent 2-3 gr difference in weight from one to the next. No big deal.
This is one of those things that you accept "because".
Because what?
Because long ago a fella weighted a pile of black powder. I't weighed X grains.
He poured it into a brass tube and scratched the tube at the top of the powder. That volume became X grains of black powder.
Since black powder is a relatively low order explosive (my term), a slight difference in powder charge makes virtually no difference in the velocity of the projectile.
Therefore his measurement is good enough for daily use.
If you are going to shoot 1000 yards all day then you probably need to weigh each charge. The same would apply to the bullseye shooter.
BUT for us regular guys that arte shooting a piece of steel or need one minute of deer accuracy the volumetric powder measure is good enough.
Just a side note. I have 5 volumetric black powder measures. There is a consistent 2-3 gr difference in weight from one to the next. No big deal.
alsaqr
Member
+1
At various times i have compared the accuracy of weighed blackpowder charges and volume charges. Came to the conclusion that it was not worthwhile to weigh charges. Any little difference in accuracy at distances to 200 yards was offset by the hassle of weighing each charge.
Inaccuracy with measured charges often comes from inconsistent measuring techniques. Some fill the measure overfull and tap the measure to "settle the powder".
In the early 1960s i met an old man who mentored me in muzzleloader stuff. "Uncle" Joe won nearly every muzzleloading contest he ever entered. He filled the powder measure slightly over full and then "struck it off" level with his finger. i still do that today.
Weight of blackpowder substitutes by volume:
http://www.curtrich.com/BPConversionSheet2005.htm
Yes, Pinnacle 3F is lighter than Pinnacle 2F.
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Driftwood Johnson
Member
Your assumption is incorrect. Pyrodex weighs less than real Black Powder. Your measurements are correct. I already answered this back on the first page. I will copy what I said here:
As has already been discussed, there is really no such thing as Grains Volume. Grains are a measurement of mass or weight. Specifically, there are exactly 7000 grains to a pound. Grains Volume is a construct that was developed when Black Powder substitutes were first developed. Pyrodex was the first sub, and it weighed significantly less than real Black Powder. But the chemical energy of Pyrodex was pretty much the same as real Black Powder when measured by volume. So using an old fashioned adjustable powder measure if one filled it to the 30 grain mark, even though the charge weighed less than a Black Powder charge thrown by the same measure, the 'explosive' energy was the same.*
Jim Watson
Member
Simpler and correct to say Pyrodex is a substitute for black powder, volume for volume.
No need to invent grains of volume.
Yes, I know about the old timers putting a rifle ball in the palm of their hand, trickling enough powder to cover the ball, and then cutting a horn, antler, or wood measure to hold that amount. They wouldn't know a grain Avoirdupois or "volume" from a cubic millihoobie.
But then there was the starting load recommended as the caliber transformed to grains weight, 50 grains powder in a .50 caliber rifle. A pretty light target load but a safe place to start... if you had a scale. A friend worked up from that until he was shooting 80 grains in one of the old Dixie .40s. I misremember whether it was FFg or FFFg. Naturally he made a volume measure to hold 80 grains of Goex for convenience in the field.
Or load a shotgun with the same dipper for both powder and shot. Mild but simple.
No need to invent grains of volume.
Yes, I know about the old timers putting a rifle ball in the palm of their hand, trickling enough powder to cover the ball, and then cutting a horn, antler, or wood measure to hold that amount. They wouldn't know a grain Avoirdupois or "volume" from a cubic millihoobie.
But then there was the starting load recommended as the caliber transformed to grains weight, 50 grains powder in a .50 caliber rifle. A pretty light target load but a safe place to start... if you had a scale. A friend worked up from that until he was shooting 80 grains in one of the old Dixie .40s. I misremember whether it was FFg or FFFg. Naturally he made a volume measure to hold 80 grains of Goex for convenience in the field.
Or load a shotgun with the same dipper for both powder and shot. Mild but simple.
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