My homemade black powder

[almar]

I have another parameter to play around with to optimize your powders efficiency. After my testing today, just like Vettpilot mentioned, high density pucks give poorer velocity than loose pucks by a significant amount. The first 2 shots were with the same powder and mesh size than the third shot, but the density of the last shot was a lot lower. The first 2 shots were with grains that measured close to 32 grains measured weight to 30 gr volume, the last shot was with 24 gr/30 vol. notice the difference.



I can quickly linearize the puck making pressure to 30/32 * 24000 lbs to obtain 22500 lbs but I doubt its linear...so ill go for about 20000 lbs and work up as required to obtain an even 1.7 gr/cc

Of course you can say that it will balance out if you just use a volumetric powder measure, but you are using more powder to obtain the same result. Which means its wasteful and likely more fouling.

This is a big bit of news I think but terrible for me because I just finished making the whole batch into pucks.

[almar]

More testing today shows that this is true as well for my other charcoal/powder ratio combinations.

In summary, just because you can get to a high density value above 1.7gr/cc, doesn't mean you should.

[DoubleBuck]

Almar;
Thank you for posting your results, good or bad! I was fixing to try to up my density, but was also wary of what I had read, on getting the density too high. I'm thinking the 1.7 G/CC must be a good number. I wish they would hurry up and ship my stinkin' grinder! I've got pucks screaming, "Grind Me!!!" haha
You may be on a record pace, for the type of pistol and load you are shooting! Since your first post, you have absolutely hit a Grand Slam, on this powder making. Congratulations and keep up the excellent work! I've been following this thread for years, and I think you've set the benchmark.

[DoubleBuck]

VettePilot;
I do pretty much the same as Nobade on the the screening. I mortar and pestle all three ingredients before milling them together and actually screen each of them through a #50 screen, to make sure they are uniform and face powder smooth. I ball mill the powder and dampen it just enough to get the pucks to press the way I want them and then fully dry them before I break them up.
My thoughts on the dry puck is that when you press a damp puck it slightly 'sponges' when the pressure is released. I think that is moisture that causes it. My thought is that if you break them up damp, the individual grains do the same thing. And, I could be completely wrong. Drying them make them harder to break up in my opinion, but the harder the better, it seems to me.

[almar]

Almar;
Thank you for posting your results, good or bad! I was fixing to try to up my density, but was also wary of what I had read, on getting the density too high. I'm thinking the 1.7 G/CC must be a good number. I wish they would hurry up and ship my stinkin' grinder! I've got pucks screaming, "Grind Me!!!" haha
You may be on a record pace, for the type of pistol and load you are shooting! Since your first post, you have absolutely hit a Grand Slam, on this powder making. Congratulations and keep up the excellent work! I've been following this thread for years, and I think you've set the benchmark.

Thank you so much DoubleBuck! Im just sharing discovery and that's the driver for me..discovery. Obviously I like good results but knowing what not to do is also important and great when I discover it. This is a very unknown territory today, knowledge mostly lost with time and it feels like I'm looking for something in a dark room sometimes but I also feel very close. We are blessed with great technology today which benefits us.

I needed another question answered and that is: What If I measure 25 grains per volume on the powder measure of the less dense stuff of 78-10-12 brown at 24 gr/30gr vol. So this stuff is obviously less than 25 grains of weight now in this powder measure, I put it in the revolver, loaded a round and it hit 839fps...now I don't know what to think anymore. How did 5 grains less produce so much velocity?

I was expecting 730 and hopeful for 760, any theories would be helpful, it felt like 839fps...heck of a bang too so I know the chrony isn't out of wack, I was far enough away. Im out of bullets I have to cast more so I cant test more for now.

Im thinking that there is just the right amount of powder than can be burned efficiently and it is about that at 25 gr volume. The more powder I added in the other tests the less burned in the cylinder and barrel optimally for that lenght of barrel and projectile weight?

If, and I mean if this is constant with more testing, then the less dense (dry pressed), but highly milled BP with low temp charcoal is the key to high performance and low fouling.

[ChrisPer]

Almar, stop me if you know this, but one feature of the revolvers is that jump from the loaded position of the ball in the chamber to the forcing cone. If you don't use a filler it gives higher velocity. It was a feature of the cartridge conversions when they started. Of course, your comparison suggests the jump may be similar in which case its just that your powder is awesome!
I use 21gns powder then a .357 case scoop of polenta under my ball in the 1858 revolver. Shorter jumps give better accuracy.

[almar]

Good point indian joe, i agree, i need to do more testing . Was running low on bullets, but i just made a bunch. I will test the powder again with 25 grains vol and weigh it to make sure its constant for every round.

The first thing i noticed after shooting these revolvers is the different sound a feel they had, deep boom versus loud crack. I bought a bunch of them after that including the walker. Its a beast. That charge must be a flame thrower.

I will eventually get myself one of those sharps rifles. Not sure which one...

[DoubleBuck]

Almar;
I'm with you on your thoughts. At this point, I think you may have hit absolute optimum burn rate for your powder, cylinder, bullet, barrel length and possibly even your cap may be optimum. If you are as tedious on your caps, I would think you could rule that out, as well. The only thought I can conclude, is like you, it must have completely burned all the powder in the barrel and maybe 5 grains more didn't. One way or the other, you are doing some pretty awesome testing and getting amazing results!

[ChrisPer]

almar's example of measurement and control got me moving on another question: what is the pressure in my press? I had worked out I could get 3500 psi maybe, if I stuck to 50mm puck die an d put my weight into the lever.
What I didn't know was the actual pressure because I am not coughing up the $ for a pressure meter. Instead I worked out the mechanical advantage, and bought a luggage scale - like a spring balance but electronic.

Wow. My first isometric pull against my own arm strength was just 11 kg.

When I simulated the pull down on the press handle I got just 22 Kg - I wanted at least 30. Now I am angry at myself for being not strong enough! So I checked the calculation.





JACK Diameters -> hydraulic advantage
80 mm big side
3 mm Assume wall thickness
7.4 cm internal dia
Area: 43 cm2
21.7 mm small side
3 mm Assume wall thickness
1.57 cm internal dia
Area: 1.94 cm2
22 :1 piston/cylinder area ratio

Leverage 50 cm long handle
4 cm moment arm from small piston to pivot
12.5 :1 leverage on small hydraulic piston.

5000 kg force on jack
225 kg force on small piston
18 kg force on jack handle

Puck die 50.5 mm dia
20.0 cm2
3.1 in2
5000 kg from the press -allegedly 8 tonne press
11000 lbs pressure
3543 psi

I only need 18Kg to get 3500 psi. Coool.
Next assumption to test: the pressure inside the die is the same all along a column of powder being pucked.

[DoubleBuck]

Indian Joe;
I'm with you, on the more shooting!
The fastest powder I have tested to date, was screened with 2% Dextrin, that I made three years ago, as a test. I weigh all my charges and of course the screened has more volume, so that may be why in a long barreled .58, it had more speed. There is definitely something to be said for screened powder, even though I have quit doing it and went to pressing pucks.

[almar]

Almar, stop me if you know this, but one feature of the revolvers is that jump from the loaded position of the ball in the chamber to the forcing cone. If you don't use a filler it gives higher velocity. It was a feature of the cartridge conversions when they started. Of course, your comparison suggests the jump may be similar in which case its just that your powder is awesome!
I use 21gns powder then a .357 case scoop of polenta under my ball in the 1858 revolver. Shorter jumps give better accuracy.

No that is a good point, although the jump couldn't be hugely different but something to consider for sure, Tip of the conical seemed right at the edge but ill keep it in mind.

[almar]

almar's example of measurement and control got me moving on another question: what is the pressure in my press? I had worked out I could get 3500 psi maybe, if I stuck to 50mm puck die an d put my weight into the lever.
What I didn't know was the actual pressure because I am not coughing up the $ for a pressure meter. Instead I worked out the mechanical advantage, and bought a luggage scale - like a spring balance but electronic.

Wow. My first isometric pull against my own arm strength was just 11 kg.

When I simulated the pull down on the press handle I got just 22 Kg - I wanted at least 30. Now I am angry at myself for being not strong enough! So I checked the calculation.





JACK Diameters -> hydraulic advantage
80 mm big side
3 mm Assume wall thickness
7.4 cm internal dia
Area: 43 cm2
21.7 mm small side
3 mm Assume wall thickness
1.57 cm internal dia
Area: 1.94 cm2
22 :1 piston/cylinder area ratio

Leverage 50 cm long handle
4 cm moment arm from small piston to pivot
12.5 :1 leverage on small hydraulic piston.

5000 kg force on jack
225 kg force on small piston
18 kg force on jack handle

Puck die 50.5 mm dia
20.0 cm2
3.1 in2
5000 kg from the press -allegedly 8 tonne press
11000 lbs pressure
3543 psi

I only need 18Kg to get 3500 psi. Coool.
Next assumption to test: the pressure inside the die is the same all along a column of powder being pucked.

hey crisper that's a pretty ingenious method to calculate the pressure. I did get those pressure meters and you can notice things happening to the pressure with them. The dry powder I pressed reached a peak of 24,000 lbs and dropped to about 22,000 lbs, I pressed it again to 24 and it stopped dropping. The minute you add a little moisture, it drops a lot faster and goes down to 8000, I bring it up again to 24 and drops again but slower. Over about half an hour it drops to 20 I usually bring it back up to 24 again and leave it for 45 min to an hour. This means the powder is compressing a lot more. You don't need them but they are quite useful and I'm a real sucker for new tools. I cant help it.

[Vettepilot]

I just bought a high pressure gauge that I'm going to install in my jack. Just a couple of holes to drill, and one to tap threads into.

I think whenever I get around to installing it, (I've had the thing for over a year), I will convert the jack to work upside down. It's just nicer that way I think.

Almar: I'm glad I thought to mention about the density. Kept ya from chasing your tail a bit there. They actually knew a hell of a lot in the old days. Amazing what they did without modern technology, actually.

Vettepilot

[DoubleBuck]

ChrisPer;
Your quote, "I only need 18Kg to get 3500 psi. Coool.
Next assumption to test: the pressure inside the die is the same all along a column of powder being pucked."
The pressure isn't. It actually is the highest at the piston, and second highest at the backing plate and third highest at junction of the highest puck in the column. The wave meets in the middle and equalizes from there. That (in my theory) is why the releasing of pressure on your press, for a short length of time (5 min.), then hitting the pressure again, is why the density raises so much. As the pressure is released, the column equalizes, but at a higher rate of compression each time. That's where the extra time becomes the key. And the minimal amount of moisture required to glue it all together.
By the way, that is a very ingenious way of figuring the pressure.

[lbrowning]

I was thinking of trying to use my floor jack to press upwards against the trailer hitch on my Jeep. The only hardware store item I have found for making pucks is a PVC sleeve, but I don't think it would stand up to high pressures. I would like to buy one of Fly's puck dies, but I don't think he's making them anymore. And yes, I know this is a janky solution, but I want to see if this even works before spending any more on it.

[ChrisPer]

It makes me really happy to learn from all your work!

That point about higher density having less than peak power is important; I want to make my powder as hot as Swiss, and that includes getting the same amount of velocity out of a BP cartridge. We have enough trouble with lower case volumes due to thick modern case web design. My old double rifle had a 110gn BP capacity in its original loading (500/450 BPE 2 3/4", 270gn .458 bullet), but if I can only get 98gn in it doesn't have a chance to shoot to the same regulation point. 'Nitro for Black' loadings, or duplex loadings, are then the only ways to keep the thing fed. (I know these would be heresy to many, but those who shoot the old British doubles have benefited from genuine research. Nitro for Black correctly loaded, gives lower pressure than BP.)
However, this is a sideshow compared with just getting normal roundball and minies flying for competition.

[ChrisPer]

I was thinking of trying to use my floor jack to press upwards against the trailer hitch on my Jeep. The only hardware store item I have found for making pucks is a PVC sleeve, but I don't think it would stand up to high pressures. I would like to buy one of Fly's puck dies, but I don't think he's making them anymore. And yes, I know this is a janky solution, but I want to see if this even works before spending any more on it.

The PVC die works fine with steel hose clamps as reinforcement. If your pressure is low, then let it sit under pressure longer.

The trailer hitch is probably only capable of putting a half ton to max a ton of weight on the jack depending on weight and CG of your vehicle, and the axle spacings relative to it.

[DoubleBuck]

I was thinking of trying to use my floor jack to press upwards against the trailer hitch on my Jeep. The only hardware store item I have found for making pucks is a PVC sleeve, but I don't think it would stand up to high pressures. I would like to buy one of Fly's puck dies, but I don't think he's making them anymore. And yes, I know this is a janky solution, but I want to see if this even works before spending any more on it.

lbrowning;
Wrap a chain around your floor jack and your die and let it press against itself. If you have a 3000 pound jack, it should work. You may have to put a flat plate on top of the pan on your jack, if it is not flat already.
If you can find a short piece of stainless or aluminum pipe to use for the die, you can make the piston out of a piece of flat aluminum plate, if you can hole saw it and blend it to fit. Another shorter piece of smaller diameter pipe setting on top of the piston, should work. I think that would get you more pressure than your jeep bumper. Just a suggestion.
If you have any machine shops near you, a lot of times they make pins and pockets. If you ask, they will probably give you both pieces, and if they are already set up, you might be surprised at how cheap they will make you a die and piston. Good luck with which ever way you go.

[almar]

It makes me really happy to learn from all your work!

That point about higher density having less than peak power is important; I want to make my powder as hot as Swiss, and that includes getting the same amount of velocity out of a BP cartridge. We have enough trouble with lower case volumes due to thick modern case web design. My old double rifle had a 110gn BP capacity in its original loading (500/450 BPE 2 3/4", 270gn .458 bullet), but if I can only get 98gn in it doesn't have a chance to shoot to the same regulation point. 'Nitro for Black' loadings, or duplex loadings, are then the only ways to keep the thing fed. (I know these would be heresy to many, but those who shoot the old British doubles have benefited from genuine research. Nitro for Black correctly loaded, gives lower pressure than BP.)

However, this is a sideshow compared with just getting normal roundball and minies flying for competition.

It could be that this theory that less dense powder is more efficient is applicable to short barrels only where the powder has less time to burn. Similar to ffg vs fffg or smokeless pistol powder vs rifle powder. But again this theory needs to be properly vetted first. It may have been irresponsible of me to post that prematurely like that after firing only one shot, now that i have a good amount of projectiles made, i will try it again soon. There could be some hidden gremlins in there too, like maybe the less dense powder turns to dust, is unstable due increased moisture absorption etc. There is often a give with a take.

[Eddie2002]

I remember reading that the rate of burn for powder is dependent on contact between the grains. There needs to be contact but some space is also needed for proper ignition. If the powder is packed too tightly or the grains are too small the flame doesn't disperse as quickly as would be found in a less dense powder column. Maybe the denser powder is reflecting this with it's slower burn. Just a though on almar's discovery.