You can find a replacement firing pin for a Stevens model 87D 22 cal rifle at a gun dealership. You can also find it by contacting the manufacturer.
Find a good gunsmith or machinist
A firing pin that is mounted on/in a hammer
Firing Pin Block
Like it says, the firing pin rotates as the action cycles.
By action of the hammer striking the firing pin, forcing it into the primer.
firing pin block
Firing pin is what strikes the back end of bullet igniting propellant
You can find a firing pin for the ranger at Numerick Gun Parts Corporation.
I am looking for a firing pin for a Crescent Firearm I believe the serial # is 8894