The flintlock mechanism is a type of lock used on muskets, pistols, and rifles in the 17th, 18th, and 19th centuries. It is commonly referred to as a "flintlock" (without the word mechanism), though that term is also commonly used for the weapons themselves as a whole, and not just the lock mechanism.
The flintlock, also known as the true flintlock, was developed in France in the early 17th century. It quickly replaced earlier technologies, such as the matchlock and wheellock and the earlier flintlocks. It continued to be in common use for over two centuries, until it was finally replaced by the percussion lock.
Construction and operationA typical flintlock mechanism has a piece of flint which is held in place in between a set of jaws on the end of a short hammer. This hammer (sometimes called the cock) is pulled back into the "cocked" position. When released by the trigger, the spring-loaded hammer moves forward, causing the flint to strike a piece of steel called the "frizzen". At the same time, the motion of the flint and hammer pushes the frizzen back, opening the cover to the pan, which contains the gunpowder. As the flint strikes the frizzen it creates a spark which falls into the pan and ignites the powder. Flame burns through a small hole into the barrel of the gun and ignites the main powder charge, causing the weapon to fire.
Most hammers follow Marin le Bourgeoys's design, and have a "half-cocked" position, which is the "safe" position since pulling the trigger from this position does not cause the gun to fire. From this position, the frizzen can be opened, and powder can be placed in the pan. Then the frizzen is closed, and the hammer is pulled back into the "full cocked" position, from which it is fired.
The phrase "don't go off half cocked" originated with these types of weapons, which were not supposed to fire from the half cocked position of the hammer.
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