BP,. weight or volume?

[joeb33050]

Powder measures dispense by volume, a surrogate for weight. We want smokeless WEIGHT to be ww.w grains.
It's time to get the BP Wt vs Volume paragraphs written.
BP is also dispensed by volume.
Some contend that the volume is what is important, not the weight. I think that this means "always use the vv.v volume, don't use ww.w weight". Weight change is ok, keep volume constant.
I've read 2 theories on this.
First, that BP absorbs water out of the air (hygroscopic) and variations in weight per volume are really variations in the amount of water there is in the BP. Yet I don't and don't see others keep any powder container open, or powder our in an open dish/bowl. I dispense BP in a Lyman 55 with the cover on, others out of plastic ketchup bottles into brass measures. If the BP isn't exposed to the air, how do the water get in? (Another ?? Wouldn't BP shoot cleaner if it had all the water it would hold and still burn right? )
Second, that the % of "fines" varies the wt./volume-but this argues for weight counting the most, doesn't it?
I recognize that the precise volume or wt. of BP isn't critical, or so I'm told.
So, does anyone know? Wt. or volume or ???-what matters?
joe b.

[Woodtroll]

Joe B.-

I have satisfied myself, with my own experimenting, that a good measure used in a consistent manner throws a volume blackpowder charge that shoots at least as consistently as those that are weighed. Notice that I did not say that the measure necessarily will throw the same WEIGHT charge each time, and that I limit this opinion to true BLACK powder only. I'm anal about these things, had been told that volume was the way to go, but had to prove it to myself by testing different loads. Develop a good consistent measure technique, and save the scales for load development. Just my (tested) opinion....

Good luck! Regan

[felix]

Use volume whenever appropriate for the loading conditions. This means, when in doubt about when the measure was used last, or which powder was used, then reset the measure (if needed) by weight. ... felix

[Junior1942]

>I dispense BP in a Lyman 55 with the cover on, others out of plastic ketchup bottles into brass measures. If the BP isn't exposed to the air, how do the water get in?

Because even inside a measure with the cover on and in a capped ketchup bottle, air is mixed with the powder. How'd you get it in the measure and how'd you get it in the bottle? You opened a can and poured it in, that's how. The air mixed with the powder inside any container will contain the exact percentage of water as the air outside the container.

Here in Louisiana where it's either raining or about to rain, the air in the powder will contain lots of water.

[Four Fingers of Death]

Most things' water content would astound you. I used to work as a paper maker about 36-37 years ago. From memory at about 4% water content, most paper starts to feel dry and crinkly, 7-8% is about normal and it starts to feel not normal at about 13% water! I can't remember the terms for these levels and am not exactly sure if my figures are right, but they are not far off.

[montana_charlie]

Powder measures dispense by volume, a surrogate for weight. We want smokeless WEIGHT to be ww.w grains.

But the metering chamber on the measure is adjusted to throw a volume that weighs a certain amount. Measure quality and technique determine whether the weigh is maintained from charge to charge. If the volume doesn't vary, the weight will remain constant.
But, even when thrown by volume, smokeless is always about 'weight'.

It's time to get the BP Wt vs Volume paragraphs written.
BP is also dispensed by volume.
Some contend that the volume is what is important, not the weight. I think that this means "always use the vv.v volume, don't use ww.w weight". Weight change is ok, keep volume constant.

Isn't that the same thing...if volume doesn't change, neither will the weight?

I've read 2 theories on this.
First, that BP absorbs water out of the air (hygroscopic) and variations in weight per volume are really variations in the amount of water there is in the BP.

Second, that the % of "fines" varies the wt./volume-but this argues for weight counting the most, doesn't it?

Even concrete absorbs moisture. I doubt that the amount of moisture absorbed by powder, smokeless or black, would make a difference you could measure...but I haven't tested that.

Running stick smokeless through a measure cuts a number of granules on each throw. You might call those pieces 'fines'. Do you worry about them being in the next charge you throw? I never have...

I recognize that the precise volume or wt. of BP isn't critical, or so I'm told.
So, does anyone know? Wt. or volume or ???-what matters?

Once you know what your rifle wants, it probably doesn't matter as long as you can be consistent. After all, the gun doesn't know a difference exists.

But going back to your statement, "BP is also dispensed by volume."

Traditionally, BP has always been dispensed by volume. But that volume has always been expressed in 'grains'...a unit of weight.

I haven't been around any of the modern-made BP powder measures (Lyman 55, Belding & Mull, etc.), but I assume that the adjustable part of the metering device has numbers on it that indicate 'number of grains'. That is certainly true of the muzzle loader's brass measure you mentioned earlier.

When you adjust a measure of that type (one intended for BP), the size of metering chamber you get when you set it for "70" is one that will hold enough water to register 70 grains on a scale. The weight of powder that particular volume will hold will be less than 70 grains.

Again, the rifle doesn't care, but knowing that your BP measure is calibrated in 'water grains' will explain why the scale seems to disagree with the markings on the measure.

So, what does matter is 'amount'...no matter how it's expressed.
CM

[felix]

If the volume of powder gets smaller, and the measure stays at the same volume, then using the measure will deliver more weight, and therefore more energy. This is not rocket science, is it? ... felix

[WBH]

Since granules of BP vary in size much more than smokeless (unless screening your BP) the concern is to have the proper volume so as to seat the bullet without any air space. It can be 58 grain or 60 grains by weight, as long as the volume is the same per cartridge. Better BP's are more consistant in weight/volume ratios. Screening is even better.

[Black Prince]

joeb33050

WBH is exactly correct. What is important is that the powder column, no matter how you measure it, is sufficient to make a minimun of contact with the bullet base. If you use a wad, it counts as part of the column. If you compress the powder, you'll have to factor that in.

Don't worry about powder asorbing moisture. Take reasonable care of it and you'll be fine. Take reasonable care in your loading techniques and procedures and you'll be fine. Leave an air space between the bullet base and the powder and you may not be fine.

Your statement "I recognize that the precise volume or wt. of BP isn't critical, or so I'm told" is correct when used on muzzle loaders because the ball or bullet is always ramed down to contact and stop against the powder. It may or may not be true loading BP cartridges.

[w30wcf]

I have come to the conclusion that the reason b.p. is recommended to be measured by volume is because not all black powders have the same density. In otherwards an = volume of Goex and Swiss typically do not weigh the same, and there can even be differences between lots.

For example, if I set my powder measure to dispense a certain volume, these are the actual weights in grains of the powders / lots I have on hand:

Goex FFG = 40.0
Kik FFG = 38.2
Swiss FFG = 45.2

I have found the best thing to do, is to determine what volume is required for my particular application. I shoot a fair amount of .44-40 and .45 Colt b.p. cartridges.

If I'm using Goex, I like a volume that will require a compression of .18"-.20" on a settled powder charge. If I'm using Swiss, I shoot for about .06-.10 compression of a settled powder charge.

Once I have determined the volume needed of a certain powder, I will weigh it for reference. Then, when I load additional cartridges using that same powder and lot no., I will double check the actual weight to make sure that the powder measure is set for the correct volume.

Works every time

w30wcf

[44man]

I always weigh my BPCR loads after throwing a charge with the measure into the pan, just habit, to get the same compression. I have also just gone directly to the drop tube from the measure and never found a difference. As far as the powder being heavier from moisture, what is the difference? If anyone can tell the difference in how one shoots compared to a dryer powder, you should be winning every single shoot in the world. I don't think the energy content of black powder changes, with a small change in moisture, enough to measure. Maybe one FPS!
I did make an experiment years ago with my muzzle loaders that was baffling. I weighed out a bunch of charges for each gun and shot bench rest with them. Accuracy was poor. I then went back to the measure (Same amount, by scale check.) and groups tightened back up. My rifles will cloverleaf shots at 50 yd's but the weighed charges would not do it, all groups were about twice as large. Been scratching my head about that ever since. I thought sure that the weighed charges would give me tighter groups.

[joeb33050]

It is said that with BP, for accurate shooting, consistent charge volume is more important than consistent charge weight. The explanations have to do with the BP absorbing water, and/or the BP having "fines" = very small grains.

BP and Water
Jim Irwin and Ed Stutz argued about whether BP absorbs water = is hygroscopic or not, on the Yahoo BPCR forum, and then agreed that BP might absorb 1%-2& water.Chemistry was employed in the arguments.
Kurt on MSN BPCR: "I loaded up some loads and shot them over a chronograph and recorded the load and taped that on a glass pint wide mouth jar and covered the jar with window screen and set it on a shelf out in the machine shed for several months to see what happens to black powder sitting open with extremes climate changes.
After a couple of months I loaded some rounds and shot them over the chrono graph again and found the same velocity's with in 3 or 4 fps + or - as before the powder was left out.
Now mind you I dont have the test equipment as a test lab has to measure the moisture level but my test told me enough that I wont worry about leaving a can of powder open for a day or so."

I read other opinions on this. I don't have any BP, but if I did I'd get a cardboard box and some tape and a saucer and some water. I'd weigh about 100 grains of BP, put it in a saucer-spread out, wet the inside of the box-maybe put a wet sponge in-, put the saucer in the box and seal it up. A day later I'd open the box, weigh the BP in the saucer, and know the answer.

BP has varying densities.
W30WCF on the Cast Boolits forum:"I have come to the conclusion that the reason b.p. is recommended to be measured by volume is because not all black powders have the same density. In otherwards an = volume of Goex and Swiss typically do not weigh the same, and there can even be differences between lots. For example, if I set my powder measure to dispense a certain volume, these are the actual weights in grains of the powders / lots I have on hand:
Goex FFG = 40.0
Kik FFG = 38.2
Swiss FFG = 45.2"

About Fines
Highwall Jack on MSN BPCR wrote: "The relative amount of "fines" in powder is something that varies with brand. I use Swiss almost exclusively and for all practical purposes, it doesn't have any fines. Some of the less premium brands I suspect have more. Some folks have discussed "screening" their powder to eliminate the fines.

Short Range Round Ball Muzzle Loaders
Most agree that for short range muzzle loading round ball shooting, charges dispensed by volume work just fine.
Dave Goodrich on the CBA forum: "Keep in mind RB shooters can and do measure by volume, when a grain difference doesn't affect the accuracy, it's just too dang easy to go by volume."
Black Prince on Cast Boolits: 'The statement "I recognize that the precise volume or wt. of BP isn't critical, or so I'm told" is correct when used on muzzle loaders because the ball or bullet is always ramed down to contact and stop against the powder. It may or may not be true loading BP cartridges."


BP and Target Muzzle Loaders
Ed Stutz on Yahoo BPCR: "In my experience BP in a round ball off hand muzzle loader 2grs makes little difference on the target, however in a round ball bench gun 2grs can make a difference at 50 or 100 yards.
Now a slug gun is a different beast; 1 or 2grs can and does make a difference; it can make a 10 ring group into an X ring group at 200 yards, I have seen a half grain do the same, though that has only happened a couple of times in 18 years. Temperature and humidity is crucial in a slug gun as they are the most temperamental guns I have ever shot, must be why I love shooting them. Most of the slug gunners weigh their charges, while round ball shooters use volume measure."

BP Cartridges
Dave Goodrich on the CBA forum: In a cartridge, volume is more important. The amount of space filling the cartridge will have a greater affect on accuracy than the weight of the charge. Weight matters, volume is a hold over from the old days when everyone carried a powder horn with a measure attached. You will find that most shooters who are serious are weighing charges for a match.

Al on MSN BPCR: "Years ago, when I got my second lot of elephant powder I loaded it by weight and came up with a charge that was much smaller in volume than I got from the previous lot. The new lot was denser. Instead of having .15" of compression I loaded the same weight and got about zero compression. It shot terrible.
As I upped the charges it shot better and better. Maybe a coincidence, but when my charge was the same volume as I had for the first lot, I got the best accuracy. In establishing an accuarate load for lot #2, volume was a much more important factor. It doesn't always happen that way, but it does often enough to get folks thinking volume is everything.
However, once a volume load is established, I'm still going to weigh each charge - again, because my volume throws are not consistent enough in weight for me."

Black Prince on Cast Boolits: "What is important is that the powder column, no matter how you measure it, is sufficient to make a minimun of contact with the bullet base. If you use a wad, it counts as part of the column. If you compress the powder, you'll have to factor that in. Don't worry about powder asorbing moisture. Take reasonable care of it and you'll be fine. Take reasonable care in your loading techniques and procedures and you'll be fine. Leave an air space between the bullet base and the powder and you may not be fine."

WBH on Cast Boolits: "Since granules of BP vary in size much more than smokeless (unless screening your BP) the concern is to have the proper volume so as to seat the bullet without any air space. It can be 58 grain or 60 grains by weight, as long as the volume is the same per cartridge. Better BP's are more consistant in weight/volume ratios. Screening is even better."

Dick Trenk Yahoo BPCR: "I would also say that from a PRACTICAL standpoint, there will NOT be a measurable difference on the target when charges vary by as much as 0.2 grains or a bit more in weight..... IF..... powder compression is kept constant.
However, when charge volume variations cause a powder compression change, then we see immediate changes in MV and group size in rifles. This is likely due to the primer brissance getting through the powder column differently when there is a change in the grains interstices.
My own tests indicate that with a given size BP charge a slight variation in compression of the "settled" powder column height does affect chrono speeds in a small but measurable amount. Therefore in order to obtain minimum variations in MV it is vital to start with a reasonably consistent charge volume not having more than 0.2 gr. to perhaps 0.3 gr. weight difference between charges."

Summary
I think that the volume vs. weight controversy results from varying densities of BP within a brand as lots change, and between brands of powder.
I think that the fines and BP absorbing water reasons are probably incorrect.
I think it's all about those varying densities and the need to maintain constant and proper column height in cartridge rifles; and has little or nothing to do with fines or water..
joe b.

[montana_charlie]

I don't have any BP, but if I did I'd weigh about 100 grains of BP, put it in a saucer-spread out, wet the inside of the box-maybe put a wet sponge in-, put the saucer in the box and seal it up. A day later I'd open the box, weigh the BP in the saucer, and know the answer.

Joe,
What you described, especially the wet sponge part, is (basically) the same method used by pipe smokers to keep their tobacco moist. I have a feeling (based on my tobacco experience) your powder would be so damp it would perform poorly...if it fired at all.

In the absence of black powder, or to avoid ruining 100 grains of a valuable commodity, you could grind up a charcoal briquette and experiment to your heart's content...
CM

[44man]

Joeb, very good and I agree. Even compression no matter what the weight is the only way to go.
I did always screen my Goex and any Pyrocrap I used, but not Swiss.
Why volume works better in the muzzle loader is a mystery though because the ball is just seated with even pressure no matter how much powder is in the barrel.

[montana_charlie]

Why volume works better in the muzzle loader is a mystery...

I've never seen any reason to believe that it does...in muzzle loaders.

All of my ML experience happened in the 70's, and was acquired in ML matches hosted by various clubs in Germany.

At different stages in my learning process, I used both methods with equal success...and still have a handful of medals, a few hunting knives, and some other prizes from those contests.
We already ate the frozen turkeys...

As it happens, the two most memorable matches I did well in were fired with weighed charges in my T/C .45 Hawken.

One of those was the first match I ever witnessed, and attended only because of an invitation to be a 'guest shooter'.
At the time, I was still searching for items to make up my kit. So, while I owned a powder scale, I had not yet acquired a volume measure of any kind.
I showed up with weighed charges poured into 7mm Rem. Mag. cases with 7mm bullets stuck in the mouths as plugs.
CM

[joeb33050]

I got a number of responses making the point that weighing charges for a ML-reducing variation-is never a BAD thing. My sense is that small variations in charge weight is a minor cause of variation; but all other things equal, the weighed charges should shoot better than volumed charges.
My results, offhand, will NOT be improved by weighing charges.
joe b.

[joeb33050]

Joe,
What you described, especially the wet sponge part, is (basically) the same method used by pipe smokers to keep their tobacco moist. I have a feeling (based on my tobacco experience) your powder would be so damp it would perform poorly...if it fired at all.

In the absence of black powder, or to avoid ruining 100 grains of a valuable commodity, you could grind up a charcoal briquette and experiment to your heart's content...
CM

I don't care if it fires, just if it absorbs water. Do you have any BP? If you do, do the test and we'll know and I'll put it in the book. We all have feelings, there's a song about it. Do the test, your feelings will be better if coupled with knowledge. Sometimes, if you want to know if it's raining, you have to look out the window. Feelings or theories don't cut it.
joe b.

[Maven]

JoeB,

"My sense is that small variations in charge weight is a minor cause of variation; but all other things equal, the weighed charges should shoot better than volumed charges."

A couple of questions: 1) Are you assuming that volumetric charges are less precise than weighed ones? 2) Are you assuming that these differences are statistically significant with respect to weight, velocity and target dispersion? 3) How small a variation of charge weight are you referrring to? I.e., do you mean small variations relative to the total charge? E.g., 5grs. variation in a 30gr. charge will have a greater effect than the same variation in a 100gr. charge. Thus, for the sake of clarity, would it be better to refer to this in terms of percentage of variation?

I too am from Missouri.

[44man]

Weighed charges in my three muzzle loaders were never as accurate as from the measure. It was not enough to effect good scores at a match though. Just some goofy thing I can't explain. I would have sworn that weighed charges just had to be better.
It takes so much black powder to increase velocity just a small amount that I don't think it matters much anyway.

[montana_charlie]

Weighed charges in my three muzzle loaders were never as accurate as from the measure.

What kind of measure were you using...and do you still have it?
CM