Definitions for "Firing pin"
In the breech mechanism of a firearm, the pin which strikes the head of the cartridge and explodes it.
when the gas lifejacket is inflated the firing pin pierces the gas canister and allows the gas to fill the bladder.
(n.) Part of a gun which strikes the primer, firing the gun. Motion may be imparted to the firing pin by striking it with a hammer, or it may itself be spring-loaded and released.