Lacl of sparks in a flint lock can be caused one of 3 sources, or a combination of two or more of them:
1. Bad " Flints".
2. Poor lock design so that the flint is not striking the frizzen at the proper angle( Angle of Impact, or AOI).
3. Soft or worn out frizzen.
I know some people like those cut agate "flints", but those I have tried are terrible. The Edges crush, and load up with steel cut from the frizzen, so that the next blow cannot cut steel- ie. no sparks.
The problem with Cutting rocks like flint, is that the cutters rarely understand, much less follow the natural fracture lines within the stone they are cutting. A knapped flint Has to follow those natural fault lines in the stone, so that when its then used for a knife, arrow, spear point, or gun flint, it fractures along its natural grain structure, breaking off a small bit of the cutting edge, to give stone an new edge.
Getting a new edge is what makes it possible for a flint to give you many consecutive shots without having to stop shooting, an re-knapp the edge.
If the Edge of your flint strikes the frizzen at a 60 degree angle, it will "self-knapp" with each blow, until is shortened to the point that the AOI is changed sufficiently that it can no longer knapp itself. Then, you move the flint forward in the jaws, brace the flint forward with a twig or other wedge, square the edge to the frizzen by knapping a new sharp edge, and go back to shooting.
If your lock is properly designed, to allow the Point of Impact on the frizzen to be 2/3 of the way up from the bottom of the face, the frizzen will open up when the flint has scraped down to 1/3 of the way up from the bottom of the face. That gives the frizzen time to get out of the way so that your sparks are THROWN down into the flash pan to ignite your flash powder.
There are often design problems involving the frizzen, the frizzen spring, the pivot screw placement, as well as the amount of tension on the main spring that affect how your lock functions, controlling how fast it fires after you pull the trigger. Most factory built locks are being made by the " More is better crowd", so that the mainsprings are massively strong- too strong to do the best work with flints. In addition, its still common, particularly with locks imported to this country from abroad, to find burrs, bends, and all other manner of problems in how the lock is designed and put together that slow its performance.
If there is a measurable delay between when the sparks ignite your flash powder, and when the gun fires, there is either something wrong with the lock, a problem with the Touchhole(vent), or operator error in how the gun is being loaded and cleaned. On the other hand, a tuned lock is a true joy to own and shoot in the hands of a skilled flintlock shooter.
No flintlock shooter will deny that there is a bit of a learning curve that has to be mastered, but the end result is greater satisfaction. :grin: :shocked2: :hatsoff: