MmSlyr,
I have been under the general impression for some time that the 2001 2Ed Lyman data for Goex2F,3F is "hotter" than the data for the 1975 1stEd Lyman data. That closeness of the old 3F to the new 2F would support that notion, but I need to examine that more closely.
Much of what I have said above in relating Ingalls data would infer that all BP is mostly the same, even across granulations except for burn rate. However, this is obviously not true with powders that we generally have access to. Ingalls was referring to the most meticulously made cannon powders of the US and England, etc, and these used the highest qualities of ingredients and processing, paid for by taxpayers.
A problem today is that BP is no longer a strategically important military material, and has not been since 1900 or so. Chemical science has come a long way since then, but there has been no big reason for governments to fund research on BP like they did in the 19th century....Fortunately the science had matured before 1900 to about the level that I can stand....or understand!
The sulfur and the potassium nitrate is pretty boring....you get it from nature or as byproduct of other important processes and you purify it and that is all doable and straightforward. It is the charcoal that is highly variable.
Charcoal can be made at higher temps or lower temps. AT higher temps there is rather obviously more carbon than at lower temps. At lower temps there is more "volatiles" (hydrocarbon) left in the charcoal than at higher temps. All this is highly influenced by the type and condition of the wood that is used to make the charcoal.
19th Century chemists (Nobel and Abel, and others) determined that the chemical reaction of burning gunpowder under high pressures was quite a bit different and more complicated than supposed by the simple equation based on 2KN03 + 3C + S => K2S + 3CO2 + 2N2. For one thing, Nobel and Abel did extensive experiments and showed that there was a whole lot of potassium chloride in the fouling (about 70% by weight of the fouling. The explanation lies in the composition of the charcoal..... a VERY simple description of "good" charcoal is C7H4O (not just C) and that hydrogen and oxygen content changes everything. I cannot show you the long and complicated chemical formual I have found in 19th century papers...space and my patience (and yours) would not permit.
Here is an excerpt from a 1952 paper I found:
"There is another factor, however, which
has considerable effect on the production of the accelerated reaction, and this is
the carbon content of the charcoal. The above experiments refer to a normal
gunpowder containing a 70 % carbon charcoal. Other experimental powders with
charcoals of different carbon contents were made and tested in a similar
manner. The results are shown in figure 19. It can be seen that the accelerated
reaction occurs most strongly with the 70 % carbon charcoal and to a less extent
with the 77.5 % carbon charcoal. With 65 % carbon there is only an indication of
acceleration, and with 53 and 95 % carbon charcoal there is no sign of
accelerated reaction. An optimum carbon content of 69 to 70 % is required to
produce maximum acceleration."
Research had determined that the volatiles (some hydrocarbons left in the charcoal and lurking) were actually a key part of the initial ignition process and that once some compounds were formed, they were reformed subsequently during the burn... and when charcoal is cooked at higher temps to get more carbon content (which, on the surface sounds better) the carbon becomes more "activated" and absorbs gas (like the "activated" charcoal filters you use to filter bad smell/taste out of water). This lessens the force of the powder instead of increasing it. There were also "brown" powders of charcoals that were made at lower temps with higher volatiles content. They burned slower and less hot (good for cannon) but also with lower overall energy content (bad for cannon).
But my point in all that rambling was that the quality of the charcoal might be quite variable. When a given source of wood supply is changed after years and years....I have read of this happening with the old Curtis and Harvey powder available thru the 1970s from England where they used to use alderwood, but were forced by depletion to change- the force of the powder can be changed because the quality of the charcoal changed.
Here in the US, I have an Army BRL paper from the 1960s that says Goex and others (then) use Maple for charcoal. But sources change over time...
For this reason, I do not expect even the same brand of powder to remain exactly the same over the years or even across different lots, depending on the care and quality control, and the fact that you get what you pay for in this respect.
If you are not careful you also can get less than you pay for ......
Sorry, I have rambled and since I am new on this site I am unaware if this has basically been said before....
YHS,
rawdog
