Estimation of changes in breech face and firing pin marks over consecutive discharges and its impact on an IBIS ® Heritage™ System

Every time a firearm is discharged, the same mechanical and chemical processes are followed to fire the bullet and eject the cartridge case. A number of markings are left on the cartridge case that can be used for comparison as a result of this process. The three marks that are commonly used for comparison are the breech face, firing pin, and ejector marks.
Source: Forensic Science International - Category: Forensic Medicine Authors: Source Type: research