Intro Ballistics Flashcards
What are the three compenonets of ballisitics?
internal, external, and terminal
What is the tragectory? What component does it belong to?
path that the bullet follows, shallow arc. External ballistics
Small arms vs artillery?
small arms, carried in hand
artillery, requires motive power
bore, barrel and muzzle?
bore- inner tube
barrel- the whole pipe
muzzle- end of gun
cartridge
single item or round or shot (shot gun)
what are the four components of a cartridge?
1) projectile
2) case or casing
3) gunpowder
4) primer
why bigger bottle neck casing in rifle casing?
more gun powder, in turn increases KE for a smaller bullet
what is a breech?
where detonation takes place. where you load the gun too
3 functions of a casing?
hold bullet
contain gunpowder
expand
primer
contains an explosive that ignites with mechanical force
what are the parts of a primer and what do they do?
the compound is crushed between the cup and the anvil. the flame goes through the flash hole and enters the gun powder
type types of gun powder? how do they differ
black and smokeless powder. smokeless has a complete conversion to gas.
two different diameters of shot gun pellets
bird and buck. 000 is called an aught
Slugs
a single shot from a shotgun. used for large game like bears or deer. fewer down range injuries because KE is lost quickly
hollow point allows
mushrooming/ bullet expansion
rifling in bore
used to cause a spin on the bullet and allow for an increase in accuracy and stability. grooves in barrel
shotguns and rifling
only if firing a slug
what does rifling help to prevent?
yawing and tumbling
penetrate vs perforate?
penetrate- entrance no exit
perforate- entrance and exit
intermediate targets
an unintentional target in the path of the bullet. cause decrease in KE and stability.
low, medium and high velocity classifications
low: <1000 ft/sec
medium: 1000-2000 ft/sec
high: > 2000 ft/sec
factors causing wound characteristics? (BITE-bone)
bullet, intermediate targets, tangential impact, pre-Exisiting fractures/ sutures etcs, and bone
What two of BTE-bone effect all wounds
bullet and bone
What are the 6 bullet factors?
strength, speed, stability, shape, size, surface treatment
calibre
max diameter of bullet or min diameter of bore
gauge
shotgun calibre, number of lead bullets that meet diamter from 1 pound of lead
different shapes
conical, wad-cutter, spitzer, hollow point
shape of bullet before and after firing depend on what?
1) bullet velocity and stability,
2) bullet construction
3) non- bullet factors
what two factors determine drag of bullet?
calibre and shape
why is is good to expand at impact
1) increase surface area
2) it decreases KE in tissue
3) rapid slowing of bullet in tissue
4) wider permanent wound track
Why lead?
heavy but soft so will deform on impact causing more damage
fragmentation
good as it causes more damge, act as secondary projectiles
richocet vs intermediate targets
ricochet- oblique rebound or skipping of bullet
intermediate target- unintentional target between firearm and true target
jacketing
covering of the bullet in a metal, usually copper, to allow for protection on integrity from heating at high high speeds
FMJ
full metal jacketing, will usually not deform
Kinetic energy equation
KE= 1/2mv^2
Theoretical vs practical increase of increasing KE
add more gun powder, better option is to increase mass
High vs low KE bullets and wound severity
low may cause more damage as more energy is given off to the tissue
Denser tissue
decreases speed and increases yaw resulting in more KE lost
Mechanisms of tissue damage?
permanent and temporay (cavitation)
intermediate target on shot gun pattern
target spreads out the spray sooner than expected
tangential targets cause entrance wound looking like what?
keyhole pattern where nose chips off some of the ectocranial skull
tangential targets cause exit wound looking like what?
key hole but everything is blown out
What do the pre-exisiting things result in?
a dissipation of energy causing a smaller than expected entrance wound
What can happen if bone is shattered by bullet?
it causes other secondary bone fragments that cause damage
bullet shape and energy transfer?
more round the bullet, more energy that is transfered
trabecular bone
theorectically because it is less dense would fracture less but false, because it is attatched to corticol bone, the bone is pulled off and causes more damage
permantent wound track
direct tissue damage to the tissues in its path
cavitation
indirect damage to the surround tissues of the wound track. high velocity bullets cause undulation and pulsating circumference
cavitation is most significant at what velocity?
> 300 m/s
amount of injury and size of wound correspond to?
direct crushing and cavitation
cavitation is esp damaging to what kind of organs?
friable, fluid-filled, and rigid
why is the brain a bad place to get shot?
its got a rigid shell and will essentially explode. its is fluid filled so will cause secondary fractures
What is important when considering amount of damage caused by a bullet
fragmentation and intergrity of the bullet
Why is cavitation truly destructive?
temporary cavitation focuses on areas weakened by fragmentation rather than being evenly spread by tissue mass.
variations of decrease in energy loss?
yaw pattern
tumbling
tissue density/ elastic differences
