Understanding the Rifling

** Caliber of the Rifled Firearm: see the spiral grooves

A Firearm is a device to propel a projectile(shot, Bullet, Missile) by the expansive force of gases generated as a result of combustion of the propellant powder in a closed space. It is of Two types

1. Smooth Bored Firearms :
where the muzzle or outer tube is smooth inside. These includes Shotguns , Muzzle loaders, and Muskets. The Shotgun is more common.

2. Rifled Firearms:
where the inside of the Muzzle is cut into spiral grooves, 4-7, which runs parellel to each other from one end to another, but in a spiral manner. This is known as Rifling, and includes Rifles, Pistols, revolver etc. The spiral cut imparts spin to the bullet , and this spinning provides Gyroscopic stability to the bullet,( just like spinning top ). This stability increases the accuracy and the exact aiming from the rifled firearms.

**Now the million dollar answer:
when the bullet is fired from the rifled firearm, the spiral cut inside the muzzle imparts specific striation marks on the bullet surface while passing through the muzzle. These spiral striations are specific only for a single firearm.

* The Forensic expert fires another bullet from the suspects pistol or firearm & matches the two bullets marks, one found on the crime scene ,and other that is test fired. If both the pattern matches then ,it is confirmed that the fire arm used is same.

So Guys now you are the Real 007 , to solve a mystery.