Piston (percussion weapon)
A piston is the part of a percussion lock that the primer is placed on. The piston is hollow, and when the hammer is knocked off, it hits the piston, causing the attached primer to ignite. The pilot jet is directed through a channel to the propellant charge and ignites it. The ignition with a primer replaced the flintlock ignition .
Pistons can easily be removed for cleaning, but also for replacement. There is also a separate key that allows it to be screwed in or out quickly. Due to the wear and tear caused by the impact of the hammer, it is necessary to replace the piston if necessary. Pistons are made of steel or of chemically and thermally resilient beryllium copper .
The thread of a piston should always be prepared with a hot screw compound ("copper paste") to prevent it from sticking.