FROM Wikipedia

French court gunsmith Marin le Bourgeoys made the first firearm incorporating a true flintlock mechanism for King Louis XIII shortly after his accession to the throne in 1610.[1] The development of firearm lock mechanisms had proceeded from matchlock to wheellock to snaplock to snaphance and miquelet in the previous two centuries, and each type had been an improvement, contributing some design features which were useful. Le Bourgeoys fitted these various features together to create the flintlock mechanism.

The new system quickly became popular, and was known and used in various forms throughout Europe by 1630. In particular, dragoons serving with the Parliamentarian army in the English Civil War were known to use snaphaunce muskets, or early forms of flintlocks. Examples of early flintlock weapons can be seen in the painting “Marie de’ Medici as Bellona” by Rubens (painted around 1622-25).

Various breech-loading flintlocks were developed starting around 1650. The most popular action has a barrel which was unscrewed from the rest of the gun. Obviously this is more practical on pistols because of the shorter barrel length. This type is known as a Queen Anne pistol because it was during her reign that it became popular (although it was actually introduced in the reign of King William III). Another type has a removable screw plug set into the side or top or bottom of the barrel. A large number of sporting rifles were made with this system, as it allowed easier loading compared with muzzle loading with a tight fitting bullet and patch.

One of the more successful was the system built by Isaac de la Chaumette starting in 1704. The barrel could be opened by 3 revolutions of the triggerguard, to which it was attached. The plug stayed attached to the barrel and the ball and powder were loaded from the top. This system was improved in the 1770s by Colonel Patrick Ferguson and 100 experimental rifles used in the American Revolutionary War. The only two flintlock breechloaders to be produced in quantity were the Hall and the Crespi. The first was invented by John Hall and patented c. 1817.[2] It was issued to the U.S Army as the Model 1819 Hall Breech Loading Rifle.[3]

The Hall rifles and carbines were loaded using a combustible paper cartridge inserted into the upward tilting breechblock. Hall rifles leaked gas from the often poorly fitted action. The same problem affected the muskets produced by Giuseppe Crespi and adopted by the Austrian Army in 1771. Nonetheless, the Crespi System was experimented with by the British during the Napoleonic Wars, and percussion Halls guns saw service in the American Civil War.

Flintlock weapons were commonly used until the mid 19th century, when they were replaced by percussion lock systems. Even though they have long been considered obsolete, flintlock weapons continue to be produced today by manufacturers such as Pedersoli, Euroarms, and Armi Sport. Not only are these weapons used by modern re-enactors, but they are also used for hunting, as many U.S. states have dedicated hunting seasons for black-powder weapons, which includes both flintlock and percussion lock weapons.