Techniques+BB

Long Guns v. Handguns Long Guns are known as rifles or shotguns. They are usually shoulder-fired, and and are accurate at long distances. Long guns use longer, more powerful bullet casings and bullets.

Handguns: Handguns, also known as pistols, are far more common in murder cases. Handguns are fired from the hand, and are easy to manipulate. Handguns are less powerful than rifles, but, due to larger calibers, can cause more damage. Types of pistols:


 * Revolver: Holds 5 to 6 rounds in a cylindrical drum.
 * [[image:http://vision.cs.princeton.edu/projects/OPTIMOL/main/revolver.jpg width="564" height="358"]]
 * Semiautomatic: Weapon loads itself after each pull of the trigger, keeping a live round in the chamber at all times.
 * [[image:http://www.randymays.com/XD9611HCSP06.jpg]]
 * Fully Automatic: Fires repeatedly by holding the trigger.
 * [[image:http://www.af.mil/news/airman/0106/00_abdefense/M16b.jpg]]

Firearms and Rifling Rifling in the barrel of a gun keeps the bullet flying in a straight path. Rifling does this by putting a clockwise spin on the bullet, like throwing a football. Rifling makes a unique mark on the bullet as it travels through the barrel, allowing ballistic analysts to determine which gun fired the bullet. These marks are like a fingerprint, and are unique to each gun. Rifling: Cartridges: Cartridges are the bullets that are fired through a gun. Cartridges vary by caliber, length, and number or grains. Typical rifle calibers are .22, 30-06, .308, and 7.62mm. Typical pistol calibers are .380, 9mm, .40, and .45.

How Firearms Work: First the gun is loaded. The magazine or drum is filled to it's capacity with ammunition. Next, the bullet is loaded into the firing chamber. When the shooter pulls the trigger, the firing pin is forced into the primer of the bullet, igniting the power inside. The bullet is forced out of the barrel. The spent cartridge is ejected out of the side of the gun if it is semiautomatic. If the gun is a revolver or single-action rifle, the spent round is ejected by hand.