Join Date: Sep 2008
Location: Bavaria, Germany - the center of 15th and 16th century gunmaking
This spirally rolled up spring used in some Japanese matchlocks is not recorded from any surviving 16th c. European, esp. German sample. On the other hand, it just seems a more refined evolution of the rolled up cord for spanning a wheellock, in a sketch by Leonardo da Vinci, ca. 1500-10 (first attachment).
Spiral springs of different device are known from one or two ca. 1550 wheellock arquebuses in the Real Armerķa. Madrid, though; they seem to be based on another drawing by da Vinci (second and third attachment).