Powder volume vs weight

[laney1566]

I have always used purchased powder measures made of brass and loaded on the line.
I recenly purchased a nice digital grain scale for checking ball weight while casting.

1. If I want to make a measure out of horn or pre-load quickloaders, can I go by weight rather than volume or is their too much of a difference?

2. Is there a conversion chart somewhere?

 

[Billnpatti]

Disregard density values and use only volume to measure your black powder. I have tried weighing black powder charges and compared the results with charges where I used only volume. There was no significant difference. It is, however, a good idea to weigh your balls and select only those that are within 1 grain of each other.
But when it comes to powder, just measure it by volume and be consistant in how you do it. If you just pour your powder into your measure and then place it into your rifle, that's okay. But if you tap your measure to settle the powder, you will get a different powder charge (more powder) than you did when you did not tap your measure. That's okay, too so long as you are consistant in your tapping. Always tap the same number of times and always tap equally hard each time. I prefer the "no tap" method as it is easier and I find it to be more consistant.

 

[Vaino]

BP charges are by weight in grains and the powder measures are sized and calibrated according to weight. Whenever I bought a powder measure calibrated by volume, I always weighed the "throw" to see if it came close to the number stamped on the measure bbl. If I'm making a powder measure for a certain charge in grains, I weigh the powder and size the measure's volume accordingly. Different granulations of BP will throw different charges from the same measure and the "pack" or density of the charge will vary according to speed of pour and the numbers of "taps" given the measure. Seeing BP isn't a high energy propellant, I've found that charges varying as much as 5 grs don't effect accuracy that much vs using smokeless powder where even a grain difference can effect accuracy. After I've first weighed the charges thrown fron a volume measure, I load directly from the measure and don't concern myself w/ charge variations thereafter.....Fred

 

[Stumpkiller]

I weigh out powder until I find a suitable load then make a measure to hold that amount (using the weighed powder to determine the proper volume).

2. Is there a conversion chart somewhere?

A conversion chart for what? Volume in cubic inches to weight? Grains to grains? How will you determine the volume of the measure? "Grains" is a weight measure whether digital or scratched on a brass tube.

Note that I have measures from unknown origin and Italy that are as much as 27% off in the marked graduations! I no longer trust the ready-made measures. T/C is pretty close - 5 to 10% different than my weighing out in either FFg or FFFg.

 

[laney1566]

I have read that BP was measured by volume. Perhaps that is what confused me. Not a big deal to me as I use a 80 grain measure.
I am new to the idea of 80 grains weight.
After reading these responses, I will simply weigh out 80 grains and pour it into an oversized horn tip and mark it for cutting till I get the correct amount of grains.
I guess I need to check all my brass measures now against my scale.
Thanks for the replies.

 

[paulvallandigham]

If you want to Weigh Powder charges with that new, electronic digital Scale, YOU CAN! Just throw 5 charges from your volume measure set for the amount that you want to shoot for best accuracy, and then weigh them all to get an AVERAGE. Now, you can use the scale to measure that Average amount of powder by WEIGHT, and you will be very close to matching the same Volume of powder if those weighed charges are put in the volume measure.

A lot of people with these scales and tubes to hold "pre-measured " powder charges, find it much faster and more accurate to use the electronic scale to get these. I am not sure how that can be, since throwing a volume of powder from my adjustable measure is about as fast as you can get. But, ignore my skepticism, please! :grin:

If you are trying to eliminate every possible Variable in your load to wring out the most accuracy from your rifle, then go ahead and weigh out the powder charges. What we are trying to caution you about is that just because a volume measure is marked indicating you are throwing 70 grains of FFFg BP, you aren't necessarily get that EXACT amount by WEIGHT, when you put that powder charge on your electronic scale. To weigh that 70 grain( by volume) charge of FFFg BP, you will have to set the electronic scale to throw whatever the Actual weight at the average weight figure you got by measuring those 5 throws of powder in the volume measure.

Years ago, I did some comparison testing on powder charges, using a modern, balance beam type scale. I found that my adjustable volume measure threw the closest numbered load by volume, when compared to its actual weight, in grains, using FFg powder. When I went to throwing FFFg powder charges, the actual weight Exceeded the volume scale by several grains. And, when I tried different loads of powder from the volume measure, I found that the degree of difference in actual weight also varied disproportionately. Then, for yuks and clucks, I tried a scoop measure I use for my shotgun, and FFg powder, and compared that larger diameter volume throw to a similar throw using my brass, adjustable powder measure. They varied considerably, with the scoop throwing more FFg and much more FFFg powder than the volume measure made of brass.

So, the lesson to be learned is that any volume measure will vary from another, if their diameters are different, and different granule BP loads will also vary in weight.

I hope this helps. :thumbsup:

 

[laney1566]

Thanks...
I am definately gonna weigh out grains on the scale when sizing my Horn Measure (the one I'm gonna make). I will load 5 charges as you suggest to get an average.
I have been considering making my own loads similar to paper cartridge but with a ticking patch inside. Not sure if it will work, but I'm gonna try

 

[hanshi]

As Paul mentioned, measures are often calibrated with maybe, 3f or 2f. This means weight may vary with the same volume. I have two adjustable measures that vary but the difference is not that much. Both differ grain weight vs volume a little as well. My advice is to measure by volume and when you arrive at your best load, weigh it then and only then.

 

[ohio ramrod]

Thanks...
I am definately gonna weigh out grains on the scale when sizing my Horn Measure (the one I'm gonna make). I will load 5 charges as you suggest to get an average.
I have been considering making my own loads similar to paper cartridge but with a ticking patch inside. Not sure if it will work, but I'm gonna try

Good luck :bow: I tried for almost a year to make a practicle paper cartridege with powder and patched round ball and gave up. I now use a loading block and wax paper powder cartridges for competition, and used horse wormer tubes for premeasured powder charges for hunting.

 

[longcruise]

I am definately gonna weigh out grains on the scale when sizing my Horn Measure (the one I'm gonna make).

Nope! That's the wrong path. First you need to measure the actual weight of the powder that your "80 grain" measure is actually throwing using the powder brand, etc that you shoot. It does not matter what it actually weighs, it only matters that it works for you. Then, start hollowing out your horn tip measure and doing weight checks with your powder as you go along. Keep working on your horn tip measure until it throws the same weight charge as the "80 grain" measure.

I have been using the same adjustable powder measure for about 25 years. I use the graduations on it to arrive at and repeat accuracy loads and I never arbitrarily change measures expecting the other graduated measure to throw the same charge if set at the same graduation number.

When I want a non-adjustable measure for the field it is made and adjusted as described above.

If you set your measure at any arbitrary setting and then throw and weigh powder from several different brands you will find a lot of variation in the actual weight of the powder. Same thing in weight variations between the granulations of the same brand of powder.

 

[Zonie]

As was mentioned, different granulations of black powder do vary when measured with a volumetric measure but the difference isn't a lot.

As for measuring the actual weight of a charge and then trimming a horn powder measure to pour that amount it sounds like that will work just fine.

The thing that needs to be mentioned here is that NONE of the modern synthetic powders have a density that is even close to black powder. They weigh less per cubic centimeter or cubic inch.
Pyrodex for instance weighs about 30 percent less for a given volume of powder.

As the modern, lighter weight synthetic black powders are made to be measured by a volumetric powder measure that is made for measuring real black powder, the energy or power contained in the volume of a given measure of black powder will be close to the energy contained in the modern synthetic black powder.

777 even goes further with this energy bit. A given volumetric measure of it produces about 15 percent MORE energy than an equal volume of real black powder.

For these reasons one should never weigh synthetic powders to obtain a powder charge that is equal to one that consists of real black powder.

 

[crockett]

I'll add a couple of thoughts. First, some time back Muzzle Blasts magazine ran a series of articles that were based on interviews with the guys winning all the black powder shoots. To the best of my recollection ALL the top shooters measured on the line- they did not use pre-measured charges based on weight. So, if you are wondering about accuracy- the evidence seems to suggest that pouring your charges on the line with a volume type measure is fine.
Now- your horn measure. If accuracy is your concern I would recommend a better measure, one that can be precisely calibrated and has a cut off top- I think you will probably get more consistent charges.
And, I shoot both black powder and modern and reload on the modern- I weigh all my charges on the modern but I have read that some of the modern bench rest shooters prefer volume rather than weight- based on the idea that slight differences in weight result in less variation than consistent volume- well- that's their contention and I'm not going to argue with guys that are putting all their shots into 1/4" groups at 100 yards.
So- I'd just use a measure and be happy- :grin: - save the digital scale for the modern ammunition.

 

[laney1566]

Guess I should have expected this when creating a vs. thread.
I will be using Goex as I have a local supplier. 2F is all I use for Rifle and my trapper pistol which is a 50 grain load. I will make 2 horn measures based off my 2 brass measures and go for exact volume. I enjoy shooting targets, but have never concerned myself with competition shooting. I am a accurate shooter and have always been no matter what weapon I use. I figure if I can put the shot in an area the size of the heart at 100 yards, then I am doing good. Thanks for all the replies. Seems that part of the fun of black powder IS ALL the variables that come along with it. It's easy to be picky when bench shooting, but I rarely ever have the opportunity to do that anyway. Freestanding with my rifle in the air is how I shoot and the biggest variable I have found is breathing along with the amount of time I take to aim before I shoot. I prefer to shoot within about 5 seconds of taking aim. Any longer and muscles become the biggest variable.
Love the forum and all the experience here. Thanks.

 

[zrifleman]

It makes a difference if you are using patch roundball or conicals. PRB isn't as sensitive to powder weight variation as cast bullets or conicals. Two of my rifles are rifled to shoot cast bullets and 5 grs makes a difference.