The Flintlock and the Percussion lock
The flintlock firearm utilizes the same ancient principle of flint and steel fire making. When a gun is fired, the cock, holding a flint in its jaws, swings through an arc, scraping the flint down the hardened steel face of the frizzen to produce a shower of sparks. The frizzen "kicks" forward, uncovering a small indentation, known as the flash pan, which contains FFFFg priming powder. The shower of sparks then ignites the priming powder. The "flash" of the ignited priming powder is carried through the touch hole, a small hole which connects the flash pan with the main powder charge in the barrel. This sequence takes place in a fraction of a second, when the gun has been properly loaded, primed and carries a sharp flint and a hardened frizzen. NOTE: The spark from a flintlock falling into an unprimed pan can, at times, fire a loaded weapon. Always treat a flintlock -- primed or unprimed -- as a loaded weapon.
As you might well imagine, all that snapping, sparking and the ignition of the priming powder can be somewhat disconcerting to the beginning buckskinner, since it takes place right next to the sights through which you will be looking. This activity makes the flintlock somewhat more difficult for the beginner to master, although it adds to the challenge of the old style of ignition.
A disadvantage which may be more difficult to overcome is its vulnerability to moisture. On particularly moist days and especially rainy days, wetness has a tendency to affect a priming charge and to prevent firing. The best solution to this problem is to pay attention to how the flintlock is primed and to protect it from the elements.
A flintlock muzzleloader is a very enjoyable and exciting firearm to use and should be tried by anyone interested in the muzzleloading sport.
The Percussion Lock
A percussion cap replaced the need for flint and frizzen. The cap is placed over the nipple of the gun, the hammer falls on the cap crushing it and igniting the fulminate inside. The "flame" from the fulminate is directed down through a flash hole (or channel) in the nipple into the main charge in the barrel. NOTE: Never let the hammer of a percussion firearm drop, unless the nipple is protected, as it will cause damage.
Although the percussion system provided a tremendous advantage over the flintlock system, its life span was shortened with the advent of cartridge guns. The flintlock, to this day, never fully disappeared from use.
Inside the Lock
As the hammer is drawn back, the tumbler rotates clockwise allowing the sear to ride along the bottom of the tumbler until it clicks into the first notch: the half-cock or safety notch. When the hammer is set in a secure half-cock notch, it should be IMPOSSIBLE to fire or move the hammer by pulling the trigger. If the hammer is then drawn back further, the sear will click into the second notch: the full-cock notch. The gun is now ready to be fired.
With the gun in the full-cock position, the trigger pressure will push upward on the rear portion of the sear to push the sear tip out of the full-cock notch. The tumbler will then rotate in a counter-clockwise direction under the pressure of the mainspring and drop the hammer to fire the gun.
Examine the Lock Before Using the Muzzleloader
Now examine the full-cock notch. To prevent the presence of a "hair" (extremely lightweight) trigger, the sear tip must adequately engage the full-cock notch. If a sear adjustment screw is provided in the tumbler of the lock, use it only to adjust the sear engagement to a safe level. Do not reduce sear engagement beyond the full face of the sear point. To do so will cause rapid wear of the sear point and notch, creating the possibility of accidental firing.
For additional information on these and other types of ignition systems, and to view animations of each type of lock