PianoManA440;
On your 1.7 Grams per CC density press.
62 grams of powder compressed to 1.7 G/CC density will produce a puck size of 36.470 CC's of volume. 80 grams of powder will produce a 1.7 Gram per CC puck with a volume of 47.05 CC's.
These are dry weights. If you add water and figure the density, you have to subtract the weight of added water, to get the correct weight. Or, you have to completely dry the puck, to get the correct weight.
You didn't state what size die you're using, or the size of your press. A 2" diameter die will produce a 1.7 G/CC puck of .863" thickness. A 3" diameter die will will produce a 1.7 G/CC puck of .406" thickness.
You said first you added 1% water, and it pressed water out of your meal, but then you said you followed the Swiss pdf and added 8% moisture? Did it not press lots of water out of it?
I hope this gave you some useable information. Good luck, and it looks like your polishing is doing good. I may be confused with some of your info, and if so, please forgive me.
ETA: These may or may not help you, with figuring density calculations. Just plug your numbers in and they will calculate or convert from inches to metric.
https://www.omnicalculator.com/math/volume
https://www.unitconverters.net/volum...inch-to-cc.htm
Last edited by DoubleBuck; 03-21-2024 at 07:38 PM.
I'm getting in the 1.7 g/cc range with a 2" die (brass pipe nipple) and a 20 ton jack. I'm adding 4 1/2% water to my green meal prior to pressing. I found that 4% didn't squeeze any moisture out during pressing and the extra 1/2% gave me just a little just a little seepage. I've weighed my pucks just after pressing and found that they quit loosing weight in the dehydrator at around 4% to constant mass. This usually gives me a high 1.6 to high 1.7 g/cc density. When I check the ground powder against Goex, I pretty consistently getting 92-93% weight to the same volume. I have found that the more fines added to the current batch will produce higher density. Usually up in the 1.8 g/cc range.
Has anyone seen a difference in accuracy with the different charcoal mixes. I read the posts of density, velocity, grain hardness ect but not much on p o i changes. Asking because I saw some change when switching from cedar char to tp char, same day same volume measure. A little more spread pattern. I did a test by mixing the two types, was doing well at fifty yds. shot enough to have to refill my flask things went south for about 10 shots then picked right back up to the poi at the start, had to quit ran out of time.
Graysmoke
Hwooldrige;
Not yet. I dont have one. But i go every spring with friends and they have one. Should have results in next month or two.
DoubleBuck;
Sorry about that. Texting leaves a lot to be desired. Soooo its a 2" diameter. Depth of.809. Subtract thickness of milk jug dividers .018x5. So volume of 37.02.
For this expdriment i put 62grams of bp plus 77.5 grains water. Which if you count water weight thats 1.85gcc.
If you dont its 1.7gcc. No leakage of any kind.
The old way i was doing it was 80grams bp plus 16 grains water. Anymore water than that and i would get seepage.
Ummmm homemade press. 6ton bottle jack between 4x4s doubled up. Conected with 1/2" threaded rod.
PianoManA440;
It's all good and I'm glad you're getting close to your target density. I just couldn't understand how you are using less powder and more water, and not pressing water out of the powder, when you were using more powder and less water, but pressing water out of it, before.
I generally use from 3% to 5% moisture, by weight, depending on Relative Humidity. I adjust until a slightly damp backing plate, but no drops of water pressed out.
If you can still find it, if you would, pass the URL to us that you found, on the Swiss Process. Thanks.
Graysmoke;
Yes, nearly every time I switch charcoal, I have a change of POI. Some, not so much as others. Sometimes, it stays good horizontally, but changes vertically. And, sometimes, it scatters, where there is not much reasoning behind it. Generally, I can increase the charges to some point, and the accuracy will come back. I do my testing with 60 grains in my rifles, because that was where I did my first tests, and I keep records of how it went. So, to compare different powders, I still do. But, more recently, I have started testing with 75 grains in the rifles, as well. The groups close up substantially, when I do.
But to answer your question, yes, I definitely have seen almost every different charcoal change POI, in one way or another. For me, it seems the better the powder, the better the groups.
Last edited by DoubleBuck; 03-22-2024 at 03:18 PM.
Man I’m glad of that, I thought my eyes went totally out on me. When it scattered on me I said *** am I doing wrong, then just as fast it went back to-where we started. I now will shoot off all my cedar and blend only tp, then I will see if that has a variance in tp char.
Thanks for the info!
Joe
I've read that those serious BPCR shooters will check or verify their load with every new lot of powder. Maybe a little different blend or different density. They say it will affect their accuracy.
I was taken totally by surprise. This 54 rifle never showed up that bad with a powder change such as schutzen to goex and minor ones with swiss. Patches and lubes were a breeze when switching, but what an awakening this was!
Proof is in the pudding!
Graysmoke
Doublebuck:
The swiss info i got from the mad monk files someone linked earlier in this thread.
Thanks to whoever posted that info. It has been very useful.
Now i just gotta go shoot new powder!!!!!
PMA440;
Mad Monk has a trove of information.
You have made a very valid point for processing pucks damp and polishing damp.
Good luck with the shooting and thanks for the info!
Superb glazing. Bill's work is one of a kind and he's gone now so it isn't like we can call him for a copy when a host goes down. So I linked what remains in the archives in the hopes his work is copied and saved for posterity.
If we don't, it joins the Library of Alexandria as unfortunately, not everything on the internet is forever not even internet archives.
Last edited by Brimstone; 03-24-2024 at 12:59 PM.
Brimstone;
I thought it was you, but couldn't remember, for a fact. I will say again, thanks for that link. I still have the text saved, for all of the files. It was some of the best information I've read.
Sandro;
https://archive.org/details/mad_monk...0complete/CTG/
This is just the opening page. The other files are listed on the left side of the page. The Complete Swiss file is 4th from the bottom of that list.
worked ok for me thanks DB
my takeaways (its about the charcoal!!!!!!!)
1) the swiss file makes pretty clear that at 75-15-10 we are making blasting grade powder - so maybe change that
2) cold burn charcoal ( been my habit anyhow )
3) cut wood just as the trees begin to bud - sap is "up" - so more sugar in the wood = more fuel. I would add to that, watch moon phase - coming up to full moon adds to this effect in all plants - maybe I harvest some proper wood instead of gathering up five year old deadfall??
4) from the Goex Express file - they experimented with longer ball milling time for their sulphur and charcoal - got them a decent way towards swiss - also described his kitchen sink method for testing fineness of grind results ---this not hard to do - I always grind my charcoal but longer is easy - never ground the sulphur separately - change that!
DoubleBuck,Thank you, my friend!
indian joe;
I noticed the recipe of 78-10-12 also. I did a test of 76-14-10 and didn't think it was better than 75-15-10. But, I am going to be trying the 78% Nitrate mix, as well. When I did the tests of the slow cooked low temp powder, of Almar's I was very limited in the quantities I could make, and dropped that recipe from my choice. I wish now I had not.
I agree with your other points. BTW, there's a full moon, tomorrow, and all the trees are just budding or leafing out, here! I may have to save back a couple of rolls of toilet paper! haha
Sandro; you're welcome, and I think you'll find some really good points from the Mad Monk Files. He was definitely an expert when it came to the manufacture, sale and use of black powder.
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |