Ballistics

E . James Radin , MD

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 Ballistics

• This lecture is designed to provide one with the basic

insight into the nature of ballistic injuries . . . . . . . . . . .
• Understanding of how projectiles carry and transfer
energy . . . . .
• Understanding direct and indirect injuries . . . . . .
• Scene information . . . .
• Patient information . . . . .
• And Patient assessment .

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 Projectiles

• Any material that travels has the ability to injure , be it

a shard of glass , a falling object , or a bullet .
• The energy within that projectile is dependent on the
velocity , the weight ( or mass in zero gravity ) , and
distance .
• Air resistance slows an object , as do barriers , gravity
can accelerate .
• Material makeup and design of a projectile can
determine how energy is transferred to the target .

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 kE = [( V2 / 7000) / 64.32 ] x grains

• Kinetic energy is a factor of velocity squared , divided by 7000 (

the number of grains in a pound ) , divided by a correction factor
of 64.32 , then all multiplied by the grain weight of the projectile .
• Velocity usually plays the major role in the energy
• Over whelming weight (mass ) can makeup for a slow velocity .
• Shape of a projectile will determine how well a object can slice
through atmosphere and hence how well it will maintain velocity .
• Low velocity is under 2000 feet/second .
• High velocity is above 2000 feet/second .

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Ballistics

• Assault Rifle
• 120 Grain bullet
• 2800 feet/second

• kE = 2090 foot pounds of

energy at the muzzle ,
but this will fall off with
distance to target .

• High velocity
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Ballistics

• Auto loading pistol

• 9 mm , 95 grain
• 1060 feet/second

• kE = 237 foot pounds

• Low velocity

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Ballistics

• Shot Gun
• 1 1/4 oz lead shot
• 1200 feet/second

• kE is determined by the
grains of the individual pellet
.

• kE = 4.4 or less foot pounds

for # 6 shot , energy falls off
rapidly

• Very low velocity 8

 Ballistics

• Not all projectiles need come from fire arms !!!

• 3000 pound car

• 30 mile per hour ( 44 feet/second )

• kE = 91,000 foot pounds of energy to a pedestrian (

361,194 foot pounds at 60 mph )

• Very low velocity but very high mass .

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 Projectile Design

• Soft Lead
• Partial Jacket , Soft Point
• Full Jacket , Pistol and Military Ball
• Hollow Point
• Wad Cutter
• Explosive
• Tracer
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Soft Lead

• Variety of shapes
• Hold together after
impact well
• will expand somewhat
• transfer energy well
• maintain velocity well
• used for both high and
low velocity applications
• very low tech , easy to
make
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Partial Jacket , Soft Point

• Complex construction
• Lead core with copper jacket
• designed to enhance
expansion yet maintain
weight
• larger wound channels
• better energy transfer
• ? More accurate at longer
ranges ?
• Can be driven at higher
velocities than lead only
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Full Metal Jacket

• Rugged , can tolerate rough

handling
• Usually military , surplus
• Can be driven at very high
velocity accurately
• Limited wound channel
• Very little expansion
• Little transfer of energy
• Damage by shock wave
• More hard tissue damage
• Also common for handguns
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Hollow Point

• Metal jacket , tip hollow

• More expansion than soft
point at lower velocities
• More energy transfer at lower
velocities
• Excellent handgun projectile
• Large amount soft tissue
damage
• High tech to manufacture

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Explosive Projectile

• Military projectile
• Explosive charge within the
projectile
• Extensive tissue damage
• Fragments throughout wound
area
• High velocity , long range
• Maintains velocity well
• Not common on the street

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Tracer Projectile

• Military application , for

directing rapid fire , see
where the projectile travels
• Not very accurate
• Surplus available
• Magnesium compound in tail
of projectile that burns when
fired
• Jacketed round
• Wound channel burned
• Extensive tissue damage
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Wad Cutter

• Lead construction
• Flat tip , Ash can shape
• Usually handgun projectile
• Good energy transfer
• Does not maintain velocity as
well
• Low velocity loading
• close in applications
• Maintains weight well after
contact

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Shot

• Multiple projectiles
• Variety of sizes
• Must calculate energy on the
basis of individual pellets
• Jagged wound channel
• Distal embolization
• Short range
• Loses velocity and energy
very quickly
• Varied composition

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 Pathology

• Design Characteristics , Special Considerations :

• Maintain weight
• Deformability
• Expansion
• Fragmentation
• Multiple Projectiles
• Organ Damage
• Wound channel size
• Shock Wave injury
• Foreign material into wound
• Thermal
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 Pathology

• Projectiles injure soft and hard tissues

• One projectile can be a multi - system trauma
• Damage is a factor of design , velocity , and distance
• Transfer of energy is a factor of design and velocity
• Distal embolization can occur when a projectile slows
enough and enters the vascular system
• Entry and exit wounds can lie ! ! ! ! ! ! Projectiles do
not have to follow a straight line !

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 Pathology

• Kinetic energy is the similarity between MVA and GSW, massive

amounts ! ! !
• 50 % of deaths are due to exsanguination
• 10 % from CNS injury
• Require rapid pressure application and evacuation , the one
exception is that of a GSW to the head . The wound is just covered
lightly
• Large bore IV’s are needed for fluid replacement
• Do not delay transport for ANY REASON ! ! ! ! ! ! !
• GSW are Treated in the Operating Room , saved in the field

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Field Assessment

• Scene Safety
• Do Incident Command ! !
• Who ‘s the patient ?
• How many ??
• Do not become one of the
patients by going in without
support
• Relay accurate information
ASAP to the receiving
hospital ! ! ! !
• A 5 minute ETA report will
not cut it ! ! ! ! 31
Field Assessment

• Observe details of the scene

• How far away was the gun
from the patient ?
• How many shots fired ?
• What type of weapon ?
• Have someone search the area
, someone could be down just
around the corner
• Patient care but remember it
is a crime scene too ! ! !

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Field Assessment

• ABC’s
• Oxygenate
• Ventilate
• IV’s and Fluid
• Rapid extrication
• Rapid Transport
• Meet any additional resources
enroute ! ! !
• Smaller hospitals do have
surgeons that can stop
internal bleeding ! ! ! And
temporize !
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Field Assessment

• Document every item

• Serial vitals
• Serial ABC’s
• Serial neurovascular
• Serial GCS
• Changes enroute
• Recheck dressings
• Recheck IV’s
• Med Command as needed
• Nausea , vomiting , pupils ,
etc.
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Hospital Assessment

• Get as much information

as you can from the
scene
• Know the number of
patients coming
• Inform EMS the number
you can handle
• Mobilize your resources
• Uncross-matched blood
ASAP to ED and OR
• Mobilize the OR 37
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Hospital Assessment

• On arrival , Repeat ABC’s

• Repeat vitals
• Examine wounds
• Fluids / Blood as needed
• Expedite OR or diagnostics
• Remember a single GSW can
be a multi-system trauma
• Fix any pneumothorax before
diagnostics

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Hospital Assessment

• Labs
• CBC
• T&C
• SMA - 20 , amylase
• PT / PTT
• U/A
• ABG
• X - Ray
• Skull , Facial
• C - Spine
• CXR
• ABD
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• Extremity
Hospital Assessment

• Procedures
• Large bore lines
• EKG
• DPL
• Monitoring
• Oxymetry
• ICP Bolt
• Mini - Lap
• Open Chest
•
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Hospital Assessment

• Special Diagnostics
• CT
• IVP
• Cysto
• DPL
• Arteriogram
• Ultrasound
• Echocardiogram
• Fetal monitoring
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 Wisdom

• GSW are multi - system events

• GSW to the head cause C - Spine injuries
• Point A - to - point B is not always a straight line ! ! !
• GSW patients have other concomitant problems :
• Drugs
• ETOH
• HIV , Hepatitis B , etc.
• Medical , pregnancy
• Surgical
• May not speak the truth
• GSW are high risk to all involved
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 Wisdom

• Think ballistic injury with all forms of trauma

• Rapid deceleration and stop can be a ballistic
injury
• A fall is a ballistic injury
• Ballistic injury can be occult just like other
penetrating events

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Summary

• The OR is the CURE ! ! !

• Rapid assessment , treatment
, and transport
• Do not by - pass a smaller
hospital with a surgically
unstable patient , they can
help you stabilize the patient
• Activate all resources as soon
as the need noted
• Use Incident Command
• Notify receiving hospital
ASAP ! ! !
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Summary

• Plan Ahead
• Know available resources
• Expect the un- expected
• Be prepared for the worst
• Oxygen and fluid , and fluid ,
and fluid !
• Serial ABC’s

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