Black powder ignition in a flintlock pan is different than inside the barrel. Here we look at black powder ignition in open air.
(Powder on sheets)
This phase of testing was suggested to me by Mr. Bill Knight. He has been a valued advisor for many years. I poured a measured amount of black powder on a sheet of paper. The powder was ignited by a red hot copper wire in different locations around the pile of powder – center, right, and left. My result was the same as Mr. Knight described. When ignited in the center the burn traveled in all directions equally. In those where the powder was ignited on the edge of the powder, the fire traveled from the ignition point toward the farthest side, away from the starting point. Included here are photos showing this.
Photo 1 — The burn radiates from the center as we would expect.
Photo 2 — Burn marks indicate the strongest direction is to the left, away from the ignition point on the right.
Photo 3 — Burn marks indicate the strongest direction is to the right, away from the ignition point on the left.
The burns marks above extended well past the area where the powder was placed. In the photos where the pile was ignited to the side, the burn marks extended considerably farther than marks left on the center ignition photo. This test was done with fffg (shown here), ffg, and ffffg powder. Each size left similar burn marks. When testing the ffg powder, I laid out all three sheets of paper side by side, thinking that I would then ignite them one at a time. When I ignited the sheet with the right side ignition, the fire moving to the left was strong enough to jump to the next sheet.
This test caused me to reconsider the long-held advice to place priming powder at the opposite end from the vent hole. This thought has been around for much longer than I have been involved in black powder. My concern is that if powder is near the outer edge of the pan, it is likely that sparks will land inboard of the powder. The experiment we just did caused me to think that the strongest part of the flame would be from the sparks across the powder- the opposite direction we want. What we desire is for the strongest flame to be at the vent end of the pan.