Interesting observations Jonas.

Of course the Reverend Forsyth's development of the Fulminate of Mercury ignition system was directly as a consequence of the delay in firing after the pan flashed over.

With regard to the speed of ignition, we discovered an interesting fact, which you may already know, quite by chance a few years ago when we did a siege at a private function for a Stately Home. Normally the Re-Enactment Society provides the powder, but in this case it was provided from the Estate. For priming they employed some very fine grained powder that they said was of the sort used in Naval ships guns, which they used as priming for a miniature brass starting cannon with which they started boat races on the lake.

Its speed of ignition was far superior to the medium stuff which we normally used.
However, when we ran out of medium powder we tried it as a main charge and it proved useless, fizzing and finally igniting with a whimper rather than a bang. The Senior Powder Master told us that because of its small grain size it packed down too tightly and insufficient oxygen could permeate between the grains to supply the combustion necessary for a quick ignition.
So that was a couple of things we found out about black powder on that day.

The only percussion firearm that I have handled was an American Colt Navy revolver, and that had quite a kick, but because I was using it double handed grip as suggested by the owner it was manageable, but quite surprising nevertheless after my Charleville Flintlock pistol.
Rob.