Forensic Ballistic Flashcards
- What is ammunition and its parts?
○ A loaded cartridge
○ Consists of a primed cartridge case, propellant and with or without one or more projectiles.
- What are the three types of ammunition?
○ Centerfire
○ Rimfire
○ Shot shell
- What is a cartridge case?
○ Container for all other components that contains all the components of a bullet:
i. Cartridge
ii. Bullet
iii. Propellant
iv. Primer
- What material is a cartridge case made of?
○ Brass
○ Steel
○ Aluminum
○ Plastic
- What is a primer?
○ It starts the explosion for propellant to burn
i. Rimfire: Priming mixture in the rim cavity of the case
ii. Centerfire: Separate self contained primer assembled centrally in the head of the cartridge case
- What is a propellant
○ The chemical composition that fills the cartridge case.
○ When ignited by the primer, large volumes of gas are produced, propelling the bullet from the firearm.
- What is shotgun ammunition?
○ Differs from rifle and handgun
○ Designed to propel multiple pellets from a smooth bore firearm
- Define Calibre
○ Term designated for the specific cartridge which a firearm is chambered
○ There is no limit or rules on how calibres are named
- What is the gauge of a firearm and how is it determined?
○ Not a unit of length but a division of Weight
- How is ammunition identified?
○ Headstamp: Stamped on the head of the cartridge case or shotshell to identify the manufacturer.
○ Measurements: Measuring the case length, rim, shoulder, neck, bullet and cross referencing with manufacturing standards.
- What is a wildcat cartridge?
Altered existing cartridges to suit their own needs and are not mass produced
Any cartridge not standardized domestically within the SAAMI.
- What are the types of firearms?
○ Rifle ○ Handgun ○ Shotgun ○ Homemade/modified ○ Black powder: Rifles, pistols (muzzleloaders), revolvers
What is the specific actions of a Rifle?
i. Bolt action
ii. Single shot or repeater firearm
iii. Lever action
iv. Self loading
v. Pump action
What is the specific actions of a Handgun?
i. Pistol (Self loading)
ii. Revolver
iii. Double or single action
What is the specific actions of a shotgun?
i. Single or double barrel
ii. side/side
iii. under/over
iv. Self loading
v. Break action
vi. Pump action
- What does a self loading pistol (glock) contain?
○ A mag, Barrel, Muzzle, Slide, Trigger, Frame, grip
- What is GSR?
Gun Shot Residue: ○ Smoke: burning of the propellant ○ Gun must contain to produce GSR: i. Lead ii. Barium iii. Antimony
- What is a handgun?
○ A firearm designed to be fired with one hand
○ Appears in 2 major types
i. Revolvers
ii. (semi)Automatic pistols
- What are the different types of shoulder arm guns?
○ Rifles
○ Automatic rifles
○ Machine guns
○ Shotguns
What are the Land and Grooves in the rifle represent?
Part of Handguns & Rifles. It is the spiral ridges and valleys in the inside the barrel.
The raised portions between the grooves are called Lands.
When the bullet fires, it creates impressions of the microscopic imperfections of the interior barrel surface called striations or striae.
What are the striations or striae represent?
When the bullet fires, it creates impressions of the microscopic imperfections of the interior barrel surface called striations or striae.
These striations or striae are then transferred to a bullet’s outer surface when it is fired.
Striations are considered to be unique to a particular barrel, through manufacturing and use.
What is the difference between a round and a shell?
A round is a single cartridge containing a projectile, propellant, primer and casing.
A shell is a form of ammunition that is fired by a large caliber cannon or artillery piece.
How is a shotgun different from a rifle?
A shotgun is like a rifle but fires many small, round pellets (grouped) or a single large slug.
Therefore, shotgun barrels do not have rifling and have a limited effective firing range.
Shotguns can fire pellets or slugs.
Shotguns do not have rifling but smoothed bore.
What is the purpose of a Choke in a shotgun?
Choke is the Measure of Constriction of a Shotgun Barrel.
Intended to Group the Pellets, and Produce a Tighter Pattern at Impact.
How if the The Size of a Shotgun Barrel is Measured?
in Gauge, Except for the Smallest, because the barrel’s internal diameter is wide
What are the striations or striae represent?
When the bullet fires, it creates impressions of the microscopic imperfections of the interior barrel surface called striations or striae.
These striations or striae are then transferred to a bullet’s outer surface when it is fired. Striations are considered to be unique to a particular barrel, through manufacturing and use.
What are the two basic types of Ammunition?
bullets and shells.
How is a bullet & Shell differ?
Bullets have a SINGLE solid projectile, propellant, a primer to ignite the propellant, and a casing to hold the components together until fired.
Shells are similar to bullets, except that the PELLETS or shot must also be held together and WADDING is inserted between them and the propellant.
The wadding maintains an even pressure on the pellets, pushing them all out of the barrel at about the same time.
What does a primer do?
The primer is what ignites the propellant.
What is a propellant?
The propellant is the fuel that propels the projectile down and out of the firearm’s barrel. (the black colour looking powder thing inside a bullet)
Smokeless powder is the most common propellant by far.
Black powder is the 1st [propellant used in firearms.
