The Collaborative International Dictionary
Firing pin \Fir"ing pin`\ In the breech mechanism of a firearm, the pin which strikes the head of the cartridge and explodes it.
Wiktionary
n. (context firearms English) the part of the firing mechanism which strikes the cartridge's primer to ignite the gunpowder.
WordNet
n. striker that ignites the charge by striking the primer
Wikipedia
A firing pin or striker is part of the firing mechanism used in a firearm or explosive device e.g. an M14 landmine or bomb fuze. Firing pins may take many forms, though the types used in fuzes for single-use devices (such as landmines, artillery shells, cluster munitions and grenades etc.) generally have a sharpened point. In contrast, firing pins used in firearms usually have a small, rounded portion designed to strike the primer of a cartridge, detonating the priming compound, which then ignites the propellant (inside) or fires the detonator and booster.
Typically, firing pins or strikers are made from steel, aluminum alloy or titanium. However, for specialist applications such as zero metal mines, non-metallic materials are used e.g. glass ceramic.
Usage examples of "firing pin".
Emptying the shells into my hand from the cylinder, I took my axe and smashed the firing pin.
He worked the bolt and fired, and the click of firing pin on empty chamber in the tunnel was like a slap in the face.
With the fluted firing pin, it's the only pistol in the world you can fire coming out of the water without having to break suction in the chamber.
The firing pin strike of the M-60 is substantial and because the round is being fired from a hot, and possibly as a result, tight chamber, pressures can be higher than normal.
By the time it is against Goto Dengo's skull, Shaftoe has his finger stuck into the gap between the hammer and the firing pin.
It would also be wasting a bullet: he only had five in his handgun, the chamber beneath the firing pin was bare.
The other and more common error is that the firing pin may be installed backwards and the gun will then not fire at all.
Ryan ripped off the safety tape, twisted loose the firing pin, dropped the handle and dropped the charge on the ground directly at their feet.
I gently squeezed again, and instantly heard the click as the firing pin pushed itself out of the head of the bolt.
Jonnie checked the revolver to make sure the one shot was going to come up under the firing pin when he cocked it.
He froze for an instant, so close to the enemy trooper that he could hear the tiny click of the firing pin.