I never had a misfire with my flinter if I do the following
I run a alcohol patch down the Bore
I remove the vent liner and clean again alcohol on a Q tip the liner and the vent in the barrel threads
I always use a new flint Black english
I dry patch the ball no lube
alcohol wipe the flint
I use a .070 vent liner and a Lyman frizzen on my t/c locks
I will make it a habit never to use a flint that strikes the frizzen again in the field for a first time out ,the strike flint goes in my box for range use only
I did like the story always great hunting in the snow