Forensic Ballistics Flashcards

Flashcards about Forensic Ballistics - Chapter 4: Firearms

What is the definition of a firearm?

Any handheld or portable weapon that expels a projectile by means of expansive force of gases from burning gunpowder or other form of combustion.

What types of firearms can be typically owned by private citizens?

Small arms or light weapons.

According to the lecture, what parts of the firearm are considered the firearm itself?

The barrel, frame, or receiver.

What is the function of the barrel in a firearm?

It is the pathway of the bullet and can be either smooth bore or rifled bore.

Name the four basic components of a firearm:

Barrel, action/mechanism, stock/grip, magazine/cylinder.

Who discovered black gunpowder?

Roger Bacon

What is the function of locking lugs?

Secure the barrel and the slide tightly together for firing

What is the function of the recoil spring?

Returning the slide forward again

What is the purpose of reaming?

To enlarge or smoothen the hole to produce the final internal diameter.

What is the function of broaching?

The construction of rifling inside the barrel.

What is the purpose of lapping?

Smoothening/polishing of the inner surface of the barrel.

What causes corrosion in a firearm barrel?

Rust due to moisture and gunpowder residues.

What causes erosion in a firearm barrel?

Mechanical wear and tear due to abrasion/friction caused by incorrect bullets.

Define Individual Characteristics of a firearm:

Characteristics that are highly unique to every firearm, determinable only after manufacture.

Define Class Characteristics of a firearm:

Characteristics common to a group of firearms, determined before manufacture; factory specifications.

What are the Class Characteristics of a Firearm?

Bore Diameter, Number of Lands and Grooves, Width of Lands, Width of Grooves, Direction of Twist, Pitch of Riflings.

What does RHT and LHT stand for when talking about Twist of Riflings of Handguns/Short Arms?

RHT means Right Hand Twist. LHT means Left Hand Twist.

List some special firearm types:

Zip gun, flare gun, harpoon gun, Gustav Gun, multi-barrel gun, Gatling gun.

What are the three types of Gunshot Residue?

Gunshot residue with lead, Gunshot residue with lead escapes near the hammer, Residue with lead is expelled.

What is the function of the extractor?

Extractor has a notch into which a cartridge rim fits snugly and pulls the spent cartridge backward with the slide

What is the function of the ejector?

Ejector is attached to the gun frame, and has a small ramp at the front that pushes a spent cartridge upward

What is the difference between a rifled bore and a smooth bore?

RIFLED BORE: barrel has spiral groove, SMOOTH BORE: barrel is smooth

What are the two construction methods for the barrel?

Smooth Bore or Rifled Bore

What is the function of the barrel?

Directs the bullet, contains rifling, creates toolmarks, determines velocity, ensures safety, stabilization, accuracy, range, identification, and classification

What are the steps in Barrel Production?

Drilling

What are the classifications of a Firearm?

Pistol, Revolver, Rifles, Shotguns, Submachine Guns, Machine Guns, Carbines, Assault Rifles, and Sniper Rifles

Describe a Pistol:

Can be fired by a single hand. Typically, there are two classifications of firearms: Semi-automatic handgun (automatically reloads when fired) or Revolver (equipped with a rotating cylinder that will hold cartridges)

What is the definition of Air Guns?

Do not fire ammo or pellets by means of gunpowder. They propel the projectile by means of compressed air.

Name 3 receiver group parts:

Receiver/Frame, Trigger, Hammer, Firing Pin

What is ballistics?

The science of projectile motion, particularly bullets and firearms

What is forensic ballistics?

The application of ballistics to legal and criminal investigations

What does the rifling do to the bullet?

Spiral grooves cut into the barrel to make bullets spin and improve accuracy

What is the caliber?

The internal diameter of the barrel, usually measured in inches or millimeters

What is a cartridge case?

The shell that holds the components of a cartridge

What is the definition of a chamber?

The portion of the barrel where the cartridge is held before firing