A tuned lock has all unnecessary friction eliminated, so that the various parts move smoothly and as fast as they are designed to move. A tuned lock has the angle of the jaw set so that the flint scrapes metal off the face of the frizzen and Throws the sparks into the pan, rather then gouging the frizzen, and the sparks rolling slowly down into the pan, maybe. A tuned lock has a fairly light frizzen spring, that is shaped so it only holds the frizzen closed, but puts no pressure on the frizzen whe the frizzen begins to open. The Tuned lock has a mainspring that has a slight let-off at full cock, so that there is some snap to throw the cock and tumbler over the top of the arc, and speed the edge of the flint into the face of the frizzen. A tuned lock has the pan set low enough below the touch hole, so that no powder covers the touch hole even when the pan is full. And, a tuned lock has the pan widened and polished to a mirror finish, the first to give a bigger target for the sparks through the using life of the flint, while the latter aids in cleaning powder residue from the pan before re-priming the pan so that moisture is not taken from the air to foul the priming powder. A tuned Lock has the Sear spring set correctly so that it is not contributing resistance to the trigger pull, or impeding the action of a set trigger to move the sear bar when the set trigger is released.
With all these characteristics satisfied, a flintlock is " tuned ", and is a joy to shoot. The main charge is actually firing before the cock finishes his stroke, and the shooter hears only a kBOOM!, with just that light " tick " sound as evidence of the flint striking the frizzen, rather than a separate Klatch-Boom, of an untuned lock. `