grains vs grains

[delmar]

If I understand correctly when you are talking about black powder and BP substitutes a grain is a measure of
volume, but when dealing with smokeless powders a grain is a measure of weight. Can I assume there is or was
a particular formula or grade of black powder in which, a grain of powder, by volume, weighs one grain?

[Delmonico]

A grain as used in reloading is 1/7000 of a pound in the Avoirdupois system of weight, 437 1/2 equal on ounce.  Black powder loading uses a full case with some compression.  The weight of a load is dertermined by the case and bullet.  If one wants to weigh charges after that is determined one can, but most load by volume.

Now where it gets confusing is when the subs come in.  What is really ment is that the volume of a sub is equal to that weight in grains of black powder.  Started with Pyrodex back when most who shot black loaded from the muzzle and by having a sub that took up the same volume you used the same powder measure.  Another one that is easy to understand but confusing for new folks, like Drahms Equivelnt for showing the power of a smokeless shotshell.

[Dick Dastardly]

Howdy Delmar,

Most likely not.  Black Powder, Genuine Powder, Holy Black, the One True Powder is volumetric and weight depends on it's density.  Since the density varies, so does weight per volume.

So, if you shoot genuine black powder, get used to volume measurements and qualify your loads depending on the quality of the black powder you choose. . .

Let's Boom!

DD-DLoS

[Cuts Crooked]

Not really.

The whole "grains volume" thing is referring to a volume of powder roughly equal to a weight of powder. As in: a 30 grain volume measure throws roughly 30 grains of powder by weight. This is not a precise measure because the various powder makers products have differing densities AND there are variations of density b'tween different batches of powder by the same maker.

This pretty much means if you want to throw EXACTLY 38 grains of a given powder, yer gonna have to weigh the charge.

Now, as has often been noted around here, this not rocket science! And for CAS purposes a volume roughly close to the weight you want will do a pretty danged good job and will be surprizingly accurate!

[Delmonico]

Even with smokeless powders volume vs weight will sometimes vary a bit from lot to lot.  That is why serious bench rest shooters most often spend big bucks on a very good powder measure and load from volume all the time once the load for a rifle is worked up.

[delmar]

Even with smokeless powders volume vs weight will sometimes vary a bit from lot to lot.  That is why serious bench rest shooters most often spend big bucks on a very good powder measure and load from volume all the time once the load for a rifle is worked up.

Now that is something I had not heard!

[delmar]

A grain as used in reloading is 1/7000 of a pound in the Avoirdupois system of weight, 437 1/2 equal on ounce.  Black powder loading uses a full case with some compression.  The weight of a load is dertermined by the case and bullet.  If one wants to weigh charges after that is determined one can, but most load by volume.

Now where it gets confusing is when the subs come in.  What is really ment is that the volume of a sub is equal to that weight in grains of black powder.  Started with Pyrodex back when most who shot black loaded from the muzzle and by having a sub that took up the same volume you used the same powder measure.  Another one that is easy to understand but confusing for new folks, like Drahms Equivelnt for showing the power of a smokeless shotshell.

I think I follow what you are saying, sort of, but it practical layman's terms, wouldn't it be fairly accurate to say, that in BP, grains are a measure of volume?

[john boy]

That is why serious bench rest shooters most often spend big bucks on a very good powder measure and load from volume all the time once the load for a rifle is worked up.

D ... ANY powder whether it is nitro or original stuff varies in density from lot to lot.   So, to load at a constant volume setting consistently for a powder column load ... the scale weight will vary.  A half grain variance of BP is immaterial for a constant load but with nitro based powders, up to a 1/2 grain means a differnce in fps and psi

My suggestion charging BP by volume would be: take the volume measurement, weigh it from lot to lot and adjust accordingly.  It's the reason I only charge BPCR for long range based on scale weight.  Charges for CAS ... let the good times roll because the distance we shoot a 5 grain variance doesn't have any negative impact on accuracy

[Delmonico]

I think I follow what you are saying, sort of, but it practical layman's terms, wouldn't it be fairly accurate to say, that in BP, grains are a measure of volume?

Grains is a volume of weight, the confusion is when folks try to use it in one way or the other for volume.  CC's is a much better system to use when measuring powder by volume.

[Pulp]

If you have a measure that throws 50 grains of LotX of Goex FFg, then obviously your measure throws 50 grains.  It also throws a volume that equals 50 grains.  If you use the same measure for Pyrodex it will only throw 40 or so grains because Pyrodex is less dense than Goex.  So some folks say you throwing 50 grains volume equivalent.  The word "equivalent" is the important word when using subs.

When you think about it, all powder measures throw powder by volume.  You just keep adjusting the measure until the volume it throws equals the weight you want. 

[Noz]

To continue what Pulp said, the same 50 gr(volume measure will not throw 50 grs (weight) of FFFg.

[Driftwood Johnson]

I think I follow what you are saying, sort of, but it practical layman's terms, wouldn't it be fairly accurate to say, that in BP, grains are a measure of volume?

Howdy

No. Grains are a unit of weight. Period. There is no such thing as a unit of volume called a grain. It is a convenience invented for the BP substitutes.

As was stated earlier, the early BP subs, like Pyrodex were formulated to have the same amount of energy as a similar volume of real Black Powder. This made it very simple to use them in conjunction with the inexpensive sliding powder measures that most muzzle loading shooters were using at the time. The slide read in grains, and had hashmarks at points indicating about how much powder would be portioned out with the slide at various positions. So if one wanted an amount of Pyrodex equal to 40 grains of BP, one set the slide at 40 and got a volume of Pyrodex with the same chemical energy as 40 grains of BP. But it did not weigh 40 grains, in fact it weighed less.

To further complicate things, not all brands of Black Powder weighs the same either. I keep a chart in my reloading notebook of some of my favorite charges and what they weigh with different brands of BP. For instance, my most common charge, 2.2CC, will weigh about 34.5 grains with Goex FFg, around 37 grains with Elephant FFg, and around 33 grains with my current favorite BP, Schuetzen FFg. It is really very simple.  Forget about grains/volume. It does not exist. When you load a cartridge with real Black Powder, pour in enough so that it is compressed around 1/16"-1/8" when the bullet is seated. If you want to weigh the powder, then weigh it, and you will find out how many grains it weighs. You can right down the figure for future reference if you want, but bear in mind, the next lot of powder may not weigh the same. If you are a serious BPCR shooter, every time you buy BP from a different lot you will qualify it. This means you load up cartridges with the new lot of powder and arrive at the charge and amount of compression that gives you the most consistant result. Then you can portion out your powder by weight, until you by some from a new lot. Then you have to do it all over again.

For CAS, it is good enough to just make up a dipper, or use a BP powder measure that portions out the same volume over and over again no matter what brand or lot you use.

[delmar]

Howdy

No. Grains are a unit of weight. Period. There is no such thing as a unit of volume called a grain. It is a convenience invented for the BP substitutes.

OK, I think I did understand all that, but if a person tells you he is using 20 grains of pyrodex, by volume,
he is not talking about weight. Correct?

[Cuts Crooked]

I think I follow what you are saying, sort of, but it practical layman's terms, wouldn't it be fairly accurate to say, that in BP, grains are a measure of volume?

Nope! Grains are a measurement of weight, period! Doesn't matter if it's BP or yer Aunties wedding ring, it's still a measure of weight. A volume measuring device that will throw 30 grains of Goex 2F from lot #XDXDXDX may, or may not throw 30 grains of Goex 2F from lot #XEXEXEX.

It is simple though, just buy/make/steal a measure that throws the amount you want to load in a cartridge and stick with it no matter what brand of BP yer using at the moment. It WILL werk more than good enuff!