My homemade black powder

[Vettepilot]

Hard to say. I'll try to re-watch that video, and maybe give it a try.

I know you've settled on 1.65 g/cc +/- as a good density. Which recipe? 78/13/10? (Is that supposed to be 78/12/10 = 100?)

Thanks,
Vettepilot

[indian joe]

So, if I did this right:

1.7 g/cc = (Commonly stated commercial density.)

1cc = 15 grains volume

@1.7 g/cc-->15 volumetric grains should weigh 1.7 grams, or 15.432 weight grains.

From that chart I posted above, we see that 15 volumetric grains of Goex 3f actually weighs 15.2 grains. So the difference is 15.432 calculated versus 15.2 weighed. Is that due to the air spaces between the granules of granulated versus a solid pressed puck? I suspect yes, but someone check me on this please.

The next column over, for Goex Express 2fg, has a weight of 15.7, which clearly either indicates a density above 1.7 g/cc, or else maybe I've figured this all wrong...

Vettepilot

ahhhh man I hope you not as confused as me by all this!

so I (take my 2cc LEE measure - checked it with a syringe is good) it holds 35.8 grains of my sample goex = 1.15 grams per cc
it holds 31.5 grains of FFg = 1.02 grams per cc

so nobody is getting commercial density in their finished powder ??? despite getting it in the puck ? a puzzle ?

[DoubleBuck]

Indian Joe;
I think the confusion is in the actual density of the powder of the powder puck versus the density of the finished powder, which is basically immaterial.
I think if you measure your Goex and a 1.7 G/CC density powder of home made, they will probably be nearly equal in volume/weight, for the same grain size. Or at least they should, if Goex is actually 1.7 density.
With the lighter density powder, even with larger grains, it will measure as you state. Lighter in weight per CC than your Goex. We got sidetracked in changing from a heavier to a lighter density, and by the syringe question; if it could be used to measure density. The short answer is no. Because the powder grains' densities were predetermined in the puck. All the syringe can be used for is basically a volume measure.

[almar]

Hard to say. I'll try to re-watch that video, and maybe give it a try.

I know you've settled on 1.65 g/cc +/- as a good density. Which recipe? 78/13/10? (Is that supposed to be 78/12/10 = 100?)

Thanks,
Vettepilot

I settled at around 1.6 g/cc and 75-15-10.

[maillemaker]

What DoubleBuck said. The density numbers we are talking about is the density of pressed pucks of essentially solid black powder. Once you break it up into powder now you have air gaps.

Now, if your puck happened to fit into a syringe then you could possibly use it as a crude way to measure its volume. Easier to just use some calipers to measure the diameter and thickness of the puck though.

Steve

[indian joe]

Indian Joe;
I think the confusion is in the actual density of the powder of the powder puck versus the density of the finished powder, which is basically immaterial.
I think if you measure your Goex and a 1.7 G/CC density powder of home made, they will probably be nearly equal in volume/weight, for the same grain size. Or at least they should, if Goex is actually 1.7 density.
With the lighter density powder, even with larger grains, it will measure as you state. Lighter in weight per CC than your Goex. We got sidetracked in changing from a heavier to a lighter density, and by the syringe question; if it could be used to measure density. The short answer is no. Because the powder grains' densities were predetermined in the puck. All the syringe can be used for is basically a volume measure.

I'll disagree with you (we still allowed to do that) to me the puck density is immaterial but the load density matters, cant have one without tother anyway - I dont reckon I can measure accurately enough on my press to determine puck density and I cant be bothered anyway. maybe I am too easily satisfied but I have good velocity, excellent consistency and clean burn. If I can keep getting same results I will be a happy camper

[HWooldridge]

Taking this a step further, the amount of compression generated by a loading press might be plenty to compress fluffy powder into a brass case, with the only requirement to leave sufficient room for the projectile. In other words, "pucking" and grinding may be unnecessary if the final load is basically equivalent in performance.

Pucking and grinding to a consistent size are probably most important in percussion revolvers, which have a limited chamber size and limited leverage to seat a ball.

[almar]

If you compress more powder into the same space you will get a denser substance.

If you compress your pucks differently every time they will produce grains with different densities.

If yours grains are very different in density they will burn differently. Like 3 f, 2f and 1f grains sizes will burn differently as well. The variance was shown to be significant from one density to another. And i mix my powder now so its important for me to be consistent.

If the system you have now works well and produces a good ES then keep with it and remain consistent. Measuring the puck density is a tool to keep you on the right track.

I found that a lighter puck produces better powder. More energy per weight and cleaner at the cost of being dustier where 1.6 or so is a good compromise. This is probably why some get great results with screened powder, but screened powder has its drawbacks of course there is no free lunch, there is always a compromise. Its up to you to judge if it a good deal for you or not.

I measure the weight of powder every time so the only thing i check now is the puck thickness every once in a while to make sure im on track during production.

With cartridges, as mentioned before, the space is limited so you need a minimum amount of powder weight fitting in there but there is a point of diminishing returns where the densest grains will only burn slowly, not produce the same peak pressure and dirty the bore without any gains in velocity. At least this is my theory base on my observations. A heavier bullet will help with better combustion but may not fix it all and maybe a lighter powder would have been better.

I think that BP work more like a smokeless pistol powder providing a harsh explosion rather than a slow push as it is with smokeless rifle powders. I get higher velocites with 2f than with 1.5 F, so the slower "bigger grains" do not propel for longer as one might think, they just slam the bullet through the barrel with less pressure. Which is why maybe some get better accuracy with grease grooved bullets and larger grains, they get transitioned in the lands more smoothly and evenly. This is provided that you don't compress that 1.5f into the case excessively enough to destroy the grains and make them into a mix of 2f and 3f. This may not apply with bore riding PP bullets or muzzle loaders...im curious to see if its true. But i digress, the purpose is to add to the idea of favoring a lighter, more explosive powder to obtain a more efficient powder. Just my 3 cents adjusted for inflation.

[DoubleBuck]

I'll disagree with you (we still allowed to do that) to me the puck density is immaterial but the load density matters, cant have one without tother anyway - I dont reckon I can measure accurately enough on my press to determine puck density and I cant be bothered anyway. maybe I am too easily satisfied but I have good velocity, excellent consistency and clean burn. If I can keep getting same results I will be a happy camper

Joe, I may have used the wrong word, by saying it is immaterial. It's all important. Point was, once you get density in the puck, the powder is set. You can't change the powder grain density, or load density. You can compress it and even compress it enough to break the grains, but then why set the grain size if you are going to compress them to the point of breaking them? I have no problem with you disagreeing. I stand by my comment that the puck sets the density. Not the load. What ever the density of the puck is, each grain of broken up and screened powder is still that same density.

[DoubleBuck]

What DoubleBuck said. The density numbers we are talking about is the density of pressed pucks of essentially solid black powder. Once you break it up into powder now you have air gaps.

Now, if your puck happened to fit into a syringe then you could possibly use it as a crude way to measure its volume. Easier to just use some calipers to measure the diameter and thickness of the puck though.

Steve

There you go. That's what I'm saying.

[maillemaker]

The British settled on a density of 1.55 as I recall from memory.

Steve

[DoubleBuck]

maillemaker;
From the book "Like Fire and Powder", he says, "I don't need to do a lot of trial-and-error experimentation, because I already know (from Waltham Abbey) that the Pattern 1853 rifle-musket shoots best with a powder of 1.55 density and a grain size of 12-20 mesh that is not graphite coated".
Good memory, young man!

[Dieselhorses]

I think after I digest all this, I can be a physicist lol. This is good stuff! My take is balancing quality with composition and compression, thus diversifying recipe for different applications.


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[Vettepilot]

Well, one "simple" thing. A 100 grain volumetric measure of Goex FFFG commercial powder weighs about 101 grains more or less. If you haven't reached that with your homemade powder, then you have not achieved the same density. That particular density is quoted as being 1.72 g/cc, which may or may not be best for your use.

Vettepilot

[Vettepilot]

It might be argued that the commercial powder, being polished, might stack the granules together more tightly, showing a higher aggregate density than your homemade, unpolished powder. In actuality, I think the difference in a 100 grain sample would be very slight...

Vettepilot

[Nobade]

I have discovered that polishing my powder makes it weigh considerably more in the volumetric measure. It most certainly packs tighter. And that is something to consider when shooting, as I discovered I am firing considerably lighter charges than I thought but the velocities are right up there with commercial for the same volume.

[DoubleBuck]

I have discovered that polishing my powder makes it weigh considerably more in the volumetric measure. It most certainly packs tighter. And that is something to consider when shooting, as I discovered I am firing considerably lighter charges than I thought but the velocities are right up there with commercial for the same volume.

Nobade;
I experienced the same thing. I've only polished my powder one time, but I think it was worth doing. It had a substantial amount of dust in it when finished.

[LAGS]

I did a couple batches and ground it to roughly 1f size.
Then I polished it in the tumbler without any media.
Then I screened it.
It came out mostly 2f and 3f.
But the weight to volume was higher on each size.
Probably because the rounded off grains left less air spaces.
Yes, it did make a lot of fines and 4f.
But that just got reprocessed.

[Dieselhorses]

Dieselhorses;
The bark and what is called bark seam are dirty. The bark seam is the dark wood around a limb sprout, that runs down into the limb base. That is where it was exposed to the air and the dirt in it, over its life. If you check the charcoal for ash, it will have more if the bark is left on. If one is not worried about ash content or the cleanliness of powder burn, it is fine to use. For example, in making fireworks lift powder, it really doesn't matter how clean the burn is. But, in a rifle, pistol, or flintlock, the cleanliness of the burn is pretty critical to accuracy and burn reliability. So, we try to clean the wood of all contamination, before cooking it. And, try to keep the ash content below 3% or so. Certainly less than 4% if possible.
Bark usually makes very slow, and dirty powder, generally speaking.

I forgot to ask that if you cook the willow with the bark on, BUT remove bark before grinding it, would it still have high ash content? I find the bark basically drops right off when cooked fully.

[Dieselhorses]

One thing I will note is that most commercial powders are graphite coated. The graphite coating supposedly helps preventing moisture uptake.

That is correct. Also helps with loading from a drop tube (if you load center-fire cartridges).