Ballistics and Firearms Flashcards
1
Q
Gun Shot Residue
A
- primer and propellant particles blown on to the shooter
- combustor products follow the bullet
- can be found on hands, clothing, people in close range or victim
- stays on hands for approximately 2 hrs., removed easily by hand washing
- help estimate range
2
Q
Ballistics v. Firearm ID
A
Ballistics: projectile in motion
Firearm ID: upon impact
3
Q
Firearms function and types
A
- explosive pressure behind a projectile to launch it
- handguns, rifles, shotguns
4
Q
Ammunition
A
- case (around propellant) is usually brass
- jacket (around lead core at tip) usually copper
- bullet diameter = caliber/gauge
5
Q
Pulling the trigger
A
- releases firing pin
- pin strikes primer
- primer ignites powder
- gas propels bullet
6
Q
Rifling
A
- Bore: interior of the firearm
- series of lands and grooves formed into the bore designed to give the projectile spin improving accuracy
7
Q
Class Characteristics
A
- lands and grooves are the same for each gun model
- bullet type, headstamp
8
Q
Accidental Characteristics
A
- drill leaving marks in the barrel
- imperfections in manufacturing
- unique striations
- breech, chamber and firing pin marks
9
Q
bullet comparisons
A
- test bullets fired through a suspect gun and microscopically prepared
- complications: striations may be due to dirt or rust
10
Q
CIBIN
A
- RCMP national and international ballistics network
11
Q
Cartridge cases characteristics and markings
A
Class: manufacturer head stamps, type, shape, caliber, composition
- all moving components leave impressions
12
Q
Breech marks
A
- when fired shell casing is forced against the breech
13
Q
reconstruction
A
- necessary to determine fire direction, flight path, zones of potential
- uses rods in holes
14
Q
Zones of possibility
A
1: probable
2: possible - may include an awkward position
3: impossible
