Firearm with identifiable ejecta

Abstract

A firearm in which a mechanical identification is integral with the surface of the chamber. Preferably the identification markings are elongated (ridges or grooves) in the direction of spent casing extraction. The extracted casings are thereby marked with a unique weapon identification number, which can easily be read by standard forensics methods.

What is claimed is:  
     
         1 . A small-arms firearm, comprising: 
 a chamber within which a cased round of ammunition can be fired to propel a projectile load through a barrel; and    an extraction mechanism which removes a spent casing from said chamber after a round has been fired therein;    wherein said chamber is internally marked with mechanical features which are elongated in the direction of motion of the spent casing when said extraction mechanism is operating.    
     
     
         2 . A method of evaluating the gun from which a spent casing was ejected, comprising the steps of: 
 (a.) recovering striagraphic identification data from said casing; and    (b.) looking up said striagraphic identification data in at least one database of unique identification data emplaced in weapons before sale.