Cylinder gap refers to the gap between the cylinder and barrel | Forensic Pathologist

Cylinder gap refers to the gap between the cylinder and barrel in a revolver handgun. When a revolver is fired, gas and soot is expelled not only from the end of the muzzle, but also from the cylinder gap. As a result, soot may be deposited on the hand that fired the gun. Pictures show soot deposition on the index finger and thumb produced by burned gunpowder particles escaping from the cylinder gap.