The wheellock mechanism, or just wheellock, was an earlier style of gun lock that preceded the flintlock, and succeeded the matchlock, making it the second gun lock to be used in an arquebus, musket or pistol.
The wheellock was invented in the early 1500s in Europe. It was a complicated mechanism, making it very expensive and could only be afforded by nobility, officers, elite guard units and rich merchants. Ordinary soldiers and citizens couldn't afford wheellocks so the matchlock was the usual type of gunlock.
Eventually, many improvements were made upon it including a pan cover over the wheel mechanism, to keep the priming dry and to prevent it from being blown away or dislodged from the pan, plus a safety catch. As well as more durable springs in the lock, given the fact that loose springs were one of its biggest weaknesses.
The wheellock utilized a serrated, spring loaded, rotating metal wheel on its side along with a moveable rotating dog which had a piece of iron pyrite clamped in its jaws. Using a spanner, the serrated wheel would be wound about 3/4 of a turn to engage the sear mechanism to set the lock. The dog would then be lowered directly onto the wheel or onto the sliding flash pan cover. This cover could automatically open by means of an internal cam mechanism upon the trigger being pulled allowing the pyrite to drop onto the wheel. After the trigger was pulled the wheel would then start turning creating sparks from the pyrite which then ignited the powder in the flashpan. This in turn then ignited the main charge in the barrel and fired the projectile.
It was important that iron pyrite was used instead of flint because the pyrite is softer than the steel of the wheel.If flint were to be used, the wheel would be ground down by the harder flint in a short time.
- List of wheellock accessories and parts (section broken into a separate article listing and giving information about the wheellock's parts and accessories)