Bullets recovered from crime scenes or bodies can tell investigators a great deal: the caliber of the weapon can be determined by measuring and/or weighing the bullet; the marks left on the bullet’s surface by the lands and grooves and twists of the barrel can reveal the manufacturer; and these same striations can be used to match the bullet to a particular suspect weapon. These striations area the most individualizing and therefore the most useful in criminal investigations involving forearms.
But what if the bullet is too damaged for such comparisons? All is not lost. An analysis of the chemical make up of the bullet might reveal not only the manufacturer but also the batch from which it came. This might serve to narrow the location of purchase and ultimately lead to the perpetrator..
Bullet Fingerprints To Help Solve Crimes: http://phys.org/news/2014-07-bullet-fingerprints-crimes.html