I've included these photographs for those unfamiliar with muzzleloaders, so that they would have a visual reference to identify the parts of both a caplock rifle and a flintlock lock mechanism.

Double set double phase triggers- These are triggers that can be fired whether they are set or not. To set them the rear trigger is pulled till it clicks, thereby making the front trigger more of a hair trigger.

Double set single phase triggers- These are triggers that MUST be set by pulling the BACK trigger until it clicks before the rifle will fire.

Drum and nipple system- The barrel that has a standard breechplug and a drum is installed at a right angle to the breechplug. The drum is drilled and tapped for the nipple. You usually find these on rifles that can be converted from caplock to flintlock.

Dry-ball- Loading your rifle without powder.

Duplex load- This is a phrase you hear particularly if you are a flint shooter wishing to use Pyrodex. It means you must use 10 gr. of blackpowder to start the charge and the remainder of Pyrodex. In other words using 2 types of powder in same load. Pyrodex requires a higher ignition temperature than does blackpowder, therefore flintlock shooters must use a small amount of black powder for the priming charge to set it off.

Fence- The raised portion of a flashpan just behind the pan under the hammer. This is to protect the shooter (or in reenacting scenarios, other shooters to the right of the shooter) from sparks from the powder and the flash when shooting a flintlock.

Flash in the pan- This is a flintlock term meaning same thing as a misfire. It's when the priming charge goes off but the main charge does not.

Fly- This is a lock part. It attaches to the tumbler which prevents the sear from reengaging into the half cock notch upon firing the weapon. A fly is required in rifles with double set triggers.

Frizzen- This is the large, flat, metal leaf that is in front of the hammer on a flintlock. It is what the flint strikes to produce the sparks. It pivots forward after being struck by the flint to expose the priming powder to the sparks.

Full cock- This is where you pull the hammer back until it clicks the second time. In this position the rifle is ready for firing.

Grain- Measurement of weight. Bullet projectiles and powder are weighed in grains. There are 437.5 grains per ounce. There are 7000 grains per pound.

Half cock- This is where you pull the hammer back until it clicks one time. This is also a built in safety meaning that while the rifle is in half cock state you cannot fire the rifle. However as with all mechanical devices you should not rely on half cock and travel with a rifle that is primed while in half cock.

Hammer- On a flintlock this is what holds the flint in a set of "jaws". On a caplock this is what falls forward striking the percussion cap on the nipple.

Hangfire- This is where there is a delay between the time the priming goes off (whether caplock or flintlock) and the main charge goes off. This is sometimes referred to as a longfire.

Hooked breech- This is where the breech end of the barrel has a "hook" on it and it literally hooks into the tang. The barrel is usually held in place with a key (wedge pin) in the forearm. This is usually found on half stock plains style rifles.

Legnth of Pull- This is a measurement to determine how long the buttstock of a rifle needs to be for a particular shooter. You will hear this if you are ordering a custom rifle. This measurement is determined by measuring from the crook of your arm at your elbow, to your trigger finger with it bent slightly as though you were going to pull a trigger. For example, my legnth of pull is 13 1/2".

Misfire- This is where the priming goes off but for some reason the main charge fails to go off.

Nipple- The cone shaped protrusion that is threaded into the breech end of the rifle, this is what the percussion cap is put on.

Patented breech- This is not the same nor should it be confused with hooked breech. You can have a hooked breech but not have patented breech. A patented breech is where the rifle fires through the breechplug itself. It has a powder chamber drilled inside the breechplug.

Primed or priming- For caplocks it means putting caps on the nipple. For flintlocks it is putting the priming powder in the flashpan.

Ramrod thimbles- These are the tubular like metal pieces under the barrel that holds the ramrod when not being used.

Rifling Twist- This is distance it takes a projectile to make 1 revolution. Example a 1 in 48 twist means it takes 48 inches of bullet travel for that same bullet to turn 1 complete turn.

Single set trigger- This is where you push the trigger FORWARD to set it. A rifle with this type of trigger can be fired set or unset.

Tang- This is the metal piece just behind the barrel and just in front of the wrist area of the rifle. On some custom guns the breechplug and tang are made as one solid piece.

Tennons- These are the metal pieces on the bottom of the barrel that you either have wedge pins running through or pins holding it in the stock.

Wedge pin- This is what goes through the stock to hold a half stock rifle in the stock.