Taylor will attest to my LOOOOOONNNNNG learning curve to shoot a flintlock.
I would call it more of a struggle, due to shooting guns having TOO much recoil, since I got my first .458 in 1973.
This developed a slightly delayed flinch, one that doesn't show with modern guns or cap-locks, but definitely displayed itself when shooting a flinter, almost every shot.
Now I can shoot a trail and perhaps only flinch a little bit
When shooting off a solid test, flint or percussion = no difference.
Offhand or standing, sometimes I make a good shot.