FORENSIC BALLISTIC - Criminology

When an empty shell is found at the scene of the crime, the presumption is an Automatic Pistol or Weapon was used. When one empty shell is found at the scene of the crime, the presumption is a Revolver was used. In the bore of a barrel, the depressed portions are the grooves, and the raised are the lands. On a fired bullet, it is the reverse. ................
................