also: げっけい
noun
firing pin
Technical term for the part of a firearm that strikes the primer to ignite the propellant.
撃茎が折れたため、その銃は撃てなくなった。
Because the firing pin broke, the gun became unable to fire.
Compound of 撃 (strike, shoot) and 茎 (stem, stalk), referring to the pin-like part that strikes the primer. The exact historical derivation is uncertain; the spelling is conventionally associated with this meaning.