16th Century Continuation 2 Ca. 1550: First use of wheel lock carbines and pistols in the cavalry. Ca. 1550: Introduction of over under pistols with two barrels on top of each other. Ca. 1560: First appearance of Dutch snaphaunce locks on guns. They have an internal mechanism, forward rotating firing steel and a movable flash pan cover. Ca. 1560: The so called petrinel, a firearm with a downward curving stock supported on the chest, is used mainly in the cavalry. Ca. 1560: First barrels with spiral rifling are most likely produced in Nürnberg. 1564: Prove stamps introduced in Suhl, Thüringen. 1566: In the ‘Fronsperger Warbook’, tromblons, weapons with trumpet shaped muzzles are mentioned for the first time.