I shot a flintlock for the first time this last weekend. I had just converted it from percussion to flint. It worked!
The delay was just like I remembered from the old Dan'l Boone TV show with Fess Parker and Ed Ames. The key is follow-through. Keep your front sight on the target awhile after pulling the trigger.
This rifle has a set trigger and it takes essentially no movement to make it fire after setting. (I
told my father it had a hair trigger. Glad he followed the four rules.) This made holding the rifle still a lot easier.