You compare the rifling marks on the bullet to the rifling in the barrel. You can also compare the firing pin mark on the primer to the firing pin on the gun.
Yes, marks are similar to tool marks left by a prying tool.
Find a good gunsmith or machinist
Sometimes. The firing pin and extractor may leave marks on an ejected shell that can be matched to a gun.
A firing pin that is mounted on/in a hammer
Firing Pin Block
Like it says, the firing pin rotates as the action cycles.
What should Firing pin protrusion measure?
By action of the hammer striking the firing pin, forcing it into the primer.
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.
Try e-gunparts.com