Originally Posted by
Maven
Glad to Ric! Larry questioned the effect of vent location* (even with the pan v. slightly above the pan v. slightly below the pan) on ignition speed/time. In short, after many trials, he found that it had little effect and that the conventional wisdom was misleading if not mistaken. The other test had to do with powder location in the pan: away from the vent v. level priming v. next to the vent, as the conventional wisdom teaches. (He even varied the vent location when testing this.) Once again, he found fastest ignition with the powder next to the vent, regardless of whether it was lower, level with, or higher than the pan. The powder banked away from the pan (all 3 locations) gave the slowest ignition times.
When I got my Dixie TN Mtn. rifle, I read and reread Sam Fadala's BP Handbook, particularly the part about flintocks. He was pretty emphatic about using a small priming charge backed away from the vent. I followed his advice and got many flashes in the pan. With a full, but level pan things improved. After reading Pletcher's article, I'm going to bank the powder next to the vent and continue to clear the vent with a brass wire to see if I can ignite the main charge 100% of the time.
*Larry had a lockplate fixture that enabled him to vary the pan : vent height.