Which concept refers to the specific marks left by a projectile?

The concept that refers to the specific marks left by a projectile is known as ballistic fingerprinting. This term describes the unique impressions made by the firearm on the projectile as it is fired, which can include tool marks from the barrel's rifling and other distinctive characteristics of the specific firearm used. Each gun tends to leave its own unique markings, akin to a fingerprint, which forensic experts can analyze to match bullets to a specific weapon. This process is essential in crime scene investigations, helping law enforcement establish links between firearms and criminal activities.

In contrast, projectile rotation relates to the stability and trajectory of a projectile during flight but does not address the markings or identifying features left on the bullet. Ballistic reference refers to a general idea or standard in ballistics, without the specificity of marking identification. Projectile designation often pertains to the naming or categorization of ammunition types, rather than the characteristics imparted onto a projectile when fired. Thus, ballistic fingerprinting is the most accurate term for describing the unique marks left by a projectile.