Forensic Ballistics: Gun, Cartridge, Toolmark, and Wound Analysis

Who invented gunpowder?

The first people to invent gunpowder were the Chinese.

Where did the first guns load bullets and powder from?

The first guns loaded bullets and powder from the muzzle.

What is a complete bullet and powder set called?

A complete bullet and powder set is called a cartridge.

What burns and pushes the projectile out of the gun?

The propellant (gunpowder) burns and pushes the projectile out of the gun.

Where does the firing pin strike to ignite the powder?

The firing pin strikes the primer to ignite the powder.

What holds all parts of the cartridge together?

The cartridge case, usually made of metal, holds all parts of the cartridge together.

What helps the gun move the cartridge around?

The extractor is designed to help the gun move the cartridge around.

What is the projectile fired from a gun called?

The projectile fired from a gun is called a bullet.

What hits the primer to fire the cartridge?

The firing pin hits the primer to fire the cartridge.

What releases the hammer and firing pin?

The trigger releases the hammer and firing pin.

What is the back of the barrel called?

The back of the barrel is called the breech.

What is the long tube through which a bullet is fired?

The long tube through which a bullet is fired is called the barrel.

What increases the accuracy of a shot?

A longer barrel generally increases the accuracy of a shot.

What does a 'hair' usually mean in firearms terminology?

A 'hair' usually refers to a short temper or a very light trigger pull.

What is the most common type of gun used by criminals?

The most common type of gun used by criminals is a handgun.

What gun is used by the US military?

The US military commonly uses the M16 or M4 rifle.

What gun has no rifling?

A smoothbore gun has no rifling.

What gun has a revolving cylinder that holds cartridges?

A revolver has a revolving cylinder that holds cartridges.

What gun is named for the grooves cut into the barrel?

A rifled gun is named for the grooves cut into the barrel.

What is a type of cartridge that has the primer on the rim?

A rimfire cartridge has the primer on the rim.

What is a bullet designed to expand on impact called?

A hollow-point bullet is designed to expand on impact.

What cartridge does the US military use?

The US military commonly uses the 5.56x45mm NATO cartridge.

What cartridge contains large numbers of small pellets?

A shotgun shell contains large numbers of small pellets.

What does 'full metal jacket' refer to?

'Full metal jacket' refers to a bullet that has a soft core encased in a shell of harder metal.

What is a toolmark?

A toolmark is an impression left by a tool on a surface.

What is rifling?

Rifling refers to the helical grooves cut into the bore of a gun barrel.

What is a land in terms of rifling?

A land is the raised portion of the rifling in a gun barrel.

What is a groove in terms of rifling?

A groove is the recessed portion of the rifling in a gun barrel.

How do you tell if rifling is left or right?

You look at the direction of the twist of the rifling.

What instrument is used to compare two bullets?

A comparison microscope is used to compare two bullets.

What is necessary to determine if a bullet came from a particular gun?

A comparison of the unique markings on the bullet and the gun's barrel is necessary.

What are three areas on a casing that can be used to compare toolmarks?

The firing pin impression, the extractor mark, and the ejector mark can be used to compare toolmarks.

What are the two major types of marks on a bullet or casing?

The two major types of marks are striations and impressions.

What are the two characteristics that determine a bullet's kinetic energy?

The mass of the bullet and its velocity determine its kinetic energy.

Which characteristic is the most important for kinetic energy?

Velocity is the most important characteristic for kinetic energy because it is squared in the kinetic energy formula.

What type of injury is a bullet wound?

A bullet wound is classified as a penetrating injury.

What is a penetrating gunshot wound?

A penetrating gunshot wound is one that does not exit the body.

What is a perforating gunshot wound?

A perforating gunshot wound is one that exits the body.

What does a slow bullet cause?

A slow bullet causes only a temporary cavity.

What does a high-speed bullet cause?

A high-speed bullet causes a temporary cavity and a permanent cavity.

Which type of cavity does more damage to the body?

The permanent cavity does more damage to the body.

Which wound is usually larger: exit or entrance?

An exit wound is usually larger than an entrance wound.

What is ballistics gel designed to do?

Ballistics gel is designed to simulate human tissue to test bullet performance.

When does stippling begin to appear?

Stippling begins to appear at distances of less than 3 feet.

What is bullet wipe?

Bullet wipe is the residue left on the surface of a target by a bullet.

Why is a 'distant' shot greater than 3 feet?

A 'distant' shot is greater than 3 feet because stippling and other marks are not present.

What happens to skin and clothing at near contact range?

At near contact range, skin and clothing may show burns or singeing.

How can you tell a near contact shot from a contact shot?

A near contact shot may show stippling, while a contact shot will show burns.

What is gunshot residue made of?

Gunshot residue is made of tiny particles from the primer and propellant.