Ballistics Flashcards
define ballistics
the scientific study of a projectile in flight
what are the 4 areas of ballistics categorised into
- Interior
- Exterior
- Terminal
- Wound
what is interior ballistics
the study of projectiles in weapons - how they behave inside the weapon
what is exterior ballistics
the study of projectiles in the air - what happens when they leave the firearm
what is terminal ballistics
the study of projectile penetration of solids - what happens when it hits something
what is wound ballistics
the study of projectile penetration of tissues
define forensic ballistics
the application of science to law in identifying used cartridge cases and fired bullets, and connecting them to a particular firearm
whats the rule regarding projectiles and kinetic energy
a moving projectile has kinetic energy proportional to its weight and velocity
how is the wounding effect of a projectile produced
by the transfer of kinetic energy from the projectile to the tissues
what is the legal definition of a firearm
a lethal barrelled weapon of any description from which any shot, bullet or other missile can be discharged
what are the three roles of firearms
- discharge a projectile with sufficient energy to kill
- ensure the projectile travels in the required direction
- ensure the bullet arrives at its target nose first - no tumbling
do firearms kill people
no - people kill people with firearms
what does ‘small arms’ include
shotguns, rifles, pistols, revolvers, cattle killers, line throwers, signal pistols, alarm guns, and nail driving or other industrial tools
what is proof (and reproof) of shotguns and small arms and why do we need it
it is the compulsory and statutory testing of every new shotgun or other small arm before sale - ensures its safety in the hands of the user
reproof is retesting
what does the proof act state
that no small arm may be sold, exchanged or exported, exposed or kept for sale, or pawned unless it has been fully proved and duly marked
define ammunition
what is, or may be, fired from a gun
name the five components of a cartridge
- Bullet
- Cartridge case
- Propellant
- Rim
- Primer
which end of a cartridge is the head
the primer (not the bullet)
what are the three main components of firearm analysis in forensic ballistics
- Evidence recovery at the crime scene
- Trace evidence recovery from clothing, hands and wounds
- Ballistics - study of how the projectile behaved
define firearm identification
any discipline of forensic science which has its primary concern to determine if a bullet, cartridge case or other ammunition component was discharged by a particular firearm
what are the potential applications of firearm analysis
- Identifying who fired a weapon
- matching weapons and comparing used bullets
- Providing evidence in the reconstruction of events
name a few examples of forensic evidence found on a semi-automatic pistol
firing pin
breech marks
rifling marks
ejector marks
GSR
gun oil traces
metallic residues
fingerprints
DNA
what is the 4 main roles of a forensic scientists in regards to ballistics
- Examine what happens to the bullet inside the barrel of a firearm during flight and when it reaches the target
- Analyse GSR
- Compare marks that may have been transferred to a bullet during ejection via a microscope
- Determine a damaged serial number of a firearm using chemical treatment
what is a head stamp composed of
letters, numbers, symbols and/ or trade names
name the main 5 types of firearms
- Rifled weapons
- Handguns
- Revolvers
- Shoulder arms or long guns
- Smooth bore weapons
what is rifling, why does it occur and how does it occur
it is the scratching of a bullet during ejection down the barrel of a firearm
it occurs due to the distinct spiral-like grooves engraved onto the barrel of a firearm to provide stability to the ammunition
what is the difference between a single and double action revolver
a single action revolver requires the user to pull back and cock the hammer manually before each fire
name a few examples of rifled long guns
semi-automatic action
pump or slide action
lever action
bolt action
single shot action
how does the damage caused by a rifle differ from a handgun
the bullets fired from a rifle travel much further with greater velocity, meaning they will impart more energy onto the target causing more damage
give an example of a smooth bore weapon
a shotgun
what is the tapering of the barrel end of a shotgun called and what does it do
a choke - condenses the shot as it comes out of the barrel, allowing for a tighter pattern of shot to travel a longer distance
what are the three ammunitions for shotguns called
birdshot
buckshot
slugs
what can we determine from bullets recovered at crime scenes and what is one drawback
the calibre and individual characteristics linking the bullet to a firearm - however they are often impacted
when comparing bullets what do we look for
the number of striations and their spacing to identify a manufacturer, as well as pinfire and breech marks to identify specific firearms
what are the three firearms databases
- NABIS - national ballistics intelligence service
- IBIS - integrated ballistics identification system
- IBIN - Interpol ballistic information network
