Thanks for the detailed description. So far I've not used Pyrodex, only FFFF BP, but would like the option 'if...'etc. So using your method, would you say there is any difference weight for weight between Pyrodex and FFFF BP? For example, is 1g Pyrodex tampered as you describe, equal to the same amount of FFFF BP?
Mass is constant. It doesn't matter what your are measuring. 1g is 1g. :wink: I know that is not what you meant. But I had to say it anyway. I'm sure someone will chime in about the speed of light and all kinds of theories, but it was a joke anyway.
Pyrodex P is supposed to produce the same energy as an identical VOLUME of FFFg (3F) black powder. Pyrodex has less mass than black powder of equal volume. So 1g of Pyrodex P should be more energetic than 1g of 3F, Triple Se7en is the lightest and most energetic...I think. Black powder measures throw volumes of known weights. So if you are using a powder measure with the grain tic marks, you can use the same amount of Pyrodex P, and I think Triple Se7en FFFg as 3F BP. If you weigh your BP, then you will need to adjust accordingly. For some reason 75% sticks in my head. If you have equal volumes of Pyrodex P and 3F BP, then the Pyrodex will weigh 75% of what the 3F weighs. I may be wrong on that, it's been years since I considered a BP substitute. Pyrodex can also be compressed more, or tamped down tighter, so you could put more in a smaller area than BP.
As I said above, Pyrodex P is a substitute for FFFg black powder. The more Fs, the smaller the grains and the more energy in a same weight. So Pyrodex P and FFFFg are probably pretty darn close pound for pound, or gram for gram. If I had to find a substitute for good ole "Holy Black", I would lean toward Triple Se7en. I think it is cleaner. Seems Pyrodex was harder to ignite as well. Which is why they have magnum primers and caps or whatever all they have.
I think Pyrodex has a shorter shelf life than black powder. It seems to be more hygroscopic. So, once opened, it will absorb more moisture from the air. How long til it is unusuable? No idea. Can always store it with a desiccant if need be.
The whole thing about the metal charge canisters cutting through the insulation is...well to be nice I will say overly-cautious. You can hold your wire straight up and pack around it, then wrap your tape and bend the wire over. I don't even do that, just bend over and tape. I use aluminum tubing, spent rifle/pistol brass and copper. Cut it, smooth it and you're G2G.