High Quality Content by WIKIPEDIA articles! A wheellock, wheel-lock or wheel lock, is a friction-wheel mechanism to cause a spark for firing a firearm. It was the next major development in firearms technology after the matchlock and the first self-igniting firearm. The mechanism is so-called because it uses a rotating steel wheel to provide ignition. Developed around AD 1500, it was used alongside the matchlock and was later superseded by the snaphance (1560s) and the flintlock (c. 1600).