Every one of these men shut their eyes! Now, that can't be good for marksmanship, can it? Let's go back a couple of centuries. Having gunpowder flash a few inches in front of your face could not have been a pleasant experience, even if you were Daniel Boone. There were probably a lot of one-eyed guys running around. Now, let's say the arrival of the percussion cap had been delayed or never happened at all. Would some smart gunsmith have come up with an in-line, hidden pan firing system for flintlock rifle? It seems to me that this would have been a problem folks would wish to solve. Did they?