Re: I am going to reload 32-40 black powder cartridges and need some tips.
When I was first learning how to make bp, I used to scoop out a sample of my powder to run lines with. I would run a thin line of my powder 6 feet long, and then I would run a thin line of store bought ffg powder an arm length away for the same distance. Then I held a stick with glowing embers in each hand and touched them down on the lines at the same time. At that point we were off to the races. Depending on how fast or slow my powder burned compared to the store bought ffg, I could tell if I had f, ff, fff, or ffff.
I have been making it for so long, I don't have to run store bought powder next to it anymore. I can just run a line of my powder by itself and know right away what my burn rate is.
If I misunderstood your question, let me know, but I think proofing the burn rate is what you were asking about. correct?