This document discusses firearm wounds and ballistics. It begins with definitions of ballistics, including interior ballistics which examines projectiles within weapons, exterior ballistics which examines projectiles in the air, and terminal/wound ballistics which examines projectile penetration of tissues. It then discusses firearm design and classification. Interior ballistics are explained, including the cycle of fire and ammunition design. Exterior ballistics are covered, specifically the forces acting on projectiles like velocity, air resistance, and gravity. Terminal ballistics are summarized as the mechanisms of wound production from projectiles, including laceration, crushing, shock waves, and cavitation.
2. Firearm Wounds
By
Dr. Arif Rasheed Malik
Associate Professor & Head
Department of Forensic Medicine & Toxicology,
SIMS, Lahore
6/15/2023 2
3. Firearm wounds
“ Firearm wounding is a special form of trauma producing a
breech through the body of a person by a bullet or shot
charge “
Principles & Practice of Forensic Medicine by Nasib R. Awan
6/15/2023 3
Firearm
“ An instrument or device with which it is possible
to propel a projectile by means of the expansive
force of the gases generated by the combustion
of an explosive substance “
4. Ballistics
“ Knowledge of physical forces acting on the
projectile & missile “ by Nasib R. Awan
Interior Ballistics
Exterior Ballistics
Terminal / Wound Ballistics
6/15/2023 4
5. 6/15/2023 5
WOUND BALLISTICS
Definitions:
Ballistics is the science of the motion of projectiles.
Interior ballistics is the study of projectiles in weapons.
External ballistics is the study of projectiles in the air.
Terminal ballistics is the study of projectile penetration of
solids.
Wound ballistics is the study of projectile penetration of
tissues.
8. INTERIOR BALLISTICS
• Knowledge of the forces responsible for
propulsion of projectile within the bore of the
barrel till the end of the projectile.
6/15/2023 8
9. 6/15/2023 9
Understanding pre-requires knowledge of:-
1- Missile design & cycle of fire.
2- Ammunition design.
Missile design & cycle of fire
Missile design:-
a- Portion containing mechanical device (not important).
b- Barrel for jetting of the projectile (Important because it has
relation to WOUND BALLISTICS).
11. Classification of Firearms
• Barrel
– Steel tube for jetting of the
projectile. Two ends ---
Breach & Muzzle end
• Bore
– Internal diameter of the
barrel. May be SMOOTH or
RIFLED
6/15/2023 11
Classified on the basis of Barrel
12. Classification of Firearms
• Smooth Bored
– Choked
– Non choked
• Rifled
– Short Barrel
– Long Barrel
6/15/2023 12
Barrel Rifling
17. TYPES OF CHOKING OF BARREL OF SHOT GUN
CHOKE PERCENTAGE OF PELLETS AT 40
YARDS IN 30 INCH CIRCLE
FULL CHOKE 65 - 75
MODIFIED CHOKE 45 - 55
IMPROVED CYLINDER 35 - 45
CYLINDER 25 - 35
6/15/2023 17
22. Ammunition Design
Projectile consists of:-
• Cartridge Case
• Primer
• Powder charge (Black or Smokeless)
• Plastic Wad
• Shot charge (Bullet or Lead shots)
6/15/2023 22
C
A
R
T
R
I
D
G
E
B
U
L
L
E
T
23. 6/15/2023 23
CARTRIDGE CASE
Function: expands and seals chamber against rearward
escape of gases.
Composition: usually brass (70% copper, 30% zinc); also
plastic and paper in shotgun shell tubes.
Shape: (a) straight ("always" pistol ammunition)
(b) bottleneck ("always" rifle ammunition)
(c) tapered ("obsolete").
Extractor flange: configuration at base; rimmed, semi-rimmed,
rimless ,belted, rebated.
Headstamp: manufacturers identifiction imprinted or embossed
on cartridge case.
24. Cartridge Case
6/15/2023 24
I. Cartridge cases (outer covering of the cartridge) are
made up of Cardboard & plastic.
II. Bullet cases are made of brass (70% copper and
30% zinc).
III. A few have a nickel coating.
IV. Primer cases are of similar composition (Cu-Zn).
V. Bullet cores are most often lead and antimony,
with a very few having a ferrous alloy core.
VI. Bullet jackets are usually brass (90% copper with
10% zinc), but some are a ferrous alloy and some
are aluminum. Some bullet coatings may also
contain nickel (Ravreby, 1982)
25. FUNCTIONS OF CARTRIDGE CASE
CONTAINS AND KEEPS THE INNER CONTENTS IN
POSITION
PREVENTS THE BACK ESCAPE OF GASES
PROTECTION TO THE CONTENTS
TYPES OF CARTRIDGE CASES
Rimmed, Semi rimmed, Rimless, Rebated, Belted
CASAELESS CARTRIDGE
6/15/2023 25
27. 6/15/2023 27
Rimmed Case : A rimmed case is distinguished by a rim that extends
outward from the head of the case, to a diameter noticeably larger than
the case body.
Semi-Rimmed : Semi-rimmed design is a rim only slightly larger than
the case body itself.
Rimless : Despite the “rimless” designation, the case does indeed have a
rim to facilitate extraction. In this design, however, the rim does not
extend beyond the case body. Rather, the rim diameter is approximately
equal to the diameter of the case body itself just ahead of the extractor
groove.
28. 6/15/2023 28
Belted : The defining characteristic of these cartridges is a small band, or
belt, around the head of the case, just ahead of the extractor groove. In
use, the belt acts in exactly the same manner as a rim. Originally, this
was an absolute necessity, owing to the steeply sloping shoulders of
many of the first belted cases.
Rebated : the rebated case is characterized by a rim that is noticeably
smaller in diameter than the case body. The intent of this design is
normally to offer increased case capacity without altering or enlarging an
existing bolt face.
29. Primer
6/15/2023 29
The major primer elements are Lead styphnate(Pb), Barium
nitrate (Ba), or Antimony sulphide(Sb). Usually, all three are
present.
Less common elements include Aluminum (Al), Sulfur (S), Tin
(Sn), Calcium (Ca), Potassium (K), Chlorine (Cl), or Silicon (Si).
Primer elements may be easier to detect in residues because
they do not get as hot as the powder, and compounds (not just
elements) may be detectable. (Tassa et al, 1982b)
31. 6/15/2023 31
Function: explodes on compression igniting the propellant.
Location: (a) centrefire. Centrally placed primer assembly
comprising primer cup (struck by firing pin), primer, anvil with flash
holes. Boxer design (USA) or Berdan design (Europe).
(b) rimfire. No primer assembly. Primer spun into rim
of cartridge case (rim struck by firing pin) and in contact with
propellant.
36. Powder Charge
Modern gunpowder, or "smokeless" powder, can contain up to
23 organic compounds (FBI study) Nitrocellulose is virtually
always present, along with other compounds containing
nitrate or nitrogen.
One of these compounds, diphenylamine (used as a stabilizer
in the powder), can be detected using reagents containing
sulfuric acid. (Maloney et al, 1982).
Modern gun powders are also described as "single-base"
when the basic ingredient is nitrocellulose and as "double-
base" when there is additionally 1 to 40% nitroglycerine
added. If nitroguanidine it is “Triple – base”.
Hardy and Chera (1979) describe a method to differentiate
them using a mass spectrometer .
6/15/2023 36
37. BLACK GUN POWDER
POTASSIUM NITRATE OR
SALT PETER
75% Charcoal is the fuel, potassium
nitrate the oxygen supplier
gives the mixture more density
and makes it more readily
ignitable
CHARCOAL 15%
SULPHUR 10%
6/15/2023 37
38. 6/15/2023 38
PROPELLANT
Function: burns to produce large volumes of gases under
pressure.
Shape: sheets of smokeless powder cut into disc, flake or
cylinder shapes.
Alternatively produced as ball and flattened ball smokeless
powder (Winchester) which may be coated with silver-black
graphite.
42. Exterior Ballistics
Interactions of forces:-
1- Forces originating from the bullet motion
a- Velocity:- i- Forward (Rate of motion (speed) and
Direction
ii- Rotational :- It varies (length of the barrel)
b- Velocity of bullet at the muzzle end for various firearms:-
i- Revolver:- 600 – 900ft/sec
ii- Pistol:- 1200 – 1440 ft/sec
iii- Rifle:- 2000 – 3500 ft/sec
2- Forces present in the medium
a- Air resistance
b- Gravity
6/15/2023 42
“ Knowledge of forces acting on the shot while it
leaves the barrel till it reaches the target “
43. Forces originating from the projectile
Velocity
1- Speed or Rate of motion also called Muzzle
velocity
• Rifles upto 2000 – 3000 fps
2- Direction of motion
• Forward motion
• Also Rotational motion in bullets due to rifling
6/15/2023 43
Bullets do
not typically
follow a
straight line
to the target.
Rotational
forces are in
effect that
keep the
bullet off a
straight axis
of flight.
44. DEFINITIONS
• YAW: is the oscillation around the long axix
of the bullet.
• PRECESSION: is a circular Yaw about the
center of gravity which takes the shape of a
decreasing spiral.
• Nutation: is a rotational movement in a small
circle which forms a rosette pattern like a
spinning top.
6/15/2023 44
45. Forces present in the medium
1- Air resistance
2- Gravity
6/15/2023 45
Curved path
Projectile
Follows..
Trajectory of bullet
47. Tail wag phenomenon
• Inside barrel projectile is
supported by walls of barrel
• Entering new medium loses
balance due to air resistance
& force of gravity
• Regains balance after
covering some distance
6/15/2023 47
Tail wag
Initial
tail wag
Intermediate
tail wag
Terminal
tail wag
48. Bullet through a glass
6/15/2023 48
Intermediate tail
wag
Secondary
misslies
49. Tail wag phenomenon
For pistol up to 60 yards
For Rifle up to 200 yards
6/15/2023 49
Medicolegal importance
Atypical firearm entry wounds
50. Terminal / Wound Ballistics
Mechanism of Wound production
Laceration & Crushing
Shock waves
Cavitation
6/15/2023 50
“ It is concerned with the effect of bullet on the
target at impact until it comes to rest “
by Naseeb R. Awan
51. Mechanism of Wound production
INTERACTION BETWEEN THE FIRE – BLAST AND PART STRUCK
FORCES IN THE FIRE - BLAST FACTORS IN THE PART STRUCK
PROJECTILE & ITS RESISTANCE OF THE TISSUE DEPENDS
UPON
DIAMETER
SHAPE NATURE,
WEIGHT DESIGN &
RIGIDITY DENSITY
TERMINAL VELOCITY (MOST
IMPORTANT)
6/15/2023 51
52. 6/15/2023 52
Projectiles disrupt tissues by two principal
mechanisms:
1. Direct laceration of the tissues as occurs with any penetrating
object ("drilling effect").
1. This is the main mechanism in low velocity gunshot wounds
e.g. from a pistol, and in such cases the permanent cavity seen
at autopsy accurately reflects the tissue damage produced by
the path of the bullet.
53. 6/15/2023 53
In high velocity rifle wounds, e.g. centrefire hunting rifles, there
is an additional effect of temporary cavity
formation.
Produced by the large amount of kinetic energy transferred to
the tissue, this cavity may be up to 30 times the diameter of the
projectile, has a lifetime of 5 to 10 milli-seconds, produces
pressures of 100 to 200 atmospheres and collapses in a pulsatile
fashion.
54. 6/15/2023 54
The diameter of the resultant permanent cavity is variable but
usually larger than the diameter of the bullet.
At autopsy, the evidence of temporary cavity formation may be
a wide zone of haemorrhage around a small permanent cavity;
this is deceptive as the tissue damage is greater than it appears
to be.
If the pressure of temporary cavity formation exceeds the elastic
limit of the tissue, then the organ may be disrupted ("bursts")
and a large permanent cavity seen at autopsy reflects the size of
the temporary cavity.
55. 6/15/2023 55
Organs which are dense (and thus cause greater loss of projectile
KE) and relatively inelastic are most susceptible to this bursting
effect e.g. liver.
Organs with low density and high elasticity are relatively protected
e.g. lung.
Organs such as muscle and skin which have similar density to liver
are relatively protected because of their elasticity.
High velocity gunshot wounds of the head produce bursting
injuries of the skull due to temporary cavity formation.
56. 6/15/2023 56
Other wounding mechanisms include:
1. Shockwaves receding from the projectile at the speed of
sound.
These may cause the rupture of gas-filled organs such as the
bowel.
2. Secondary projectiles such as shattered bone fragments e.g.
gunshot wounds to the head.
3. Discharge gases exiting the muzzle of the weapon pass into
the wound track in hard contact wounds and produce tissue
disruption e.g. contact shotgun wounds to the head.
57. Laceration & Crushing
• Velocity is a key factor to the overall extent of gunshot
wounds
• According to the kinetic energy equation: (kinetic energy =
mass/ 2 x velocity2) Doubling the mass doubles the energy,
however doubling the velocity quadruples the energy
• Therefore a small-caliber bullet traveling at high speed can
produce a more extensive injury than larger caliber bullet
traveling at a lower speed
6/15/2023 57
Kinematics is the science of motion. In gunshot
wounds we can use this to determine the extent of
injury from the forces and motion involved.
58. Laceration & Crushing
…. produced by the direct effect of bullet
1- Missile velocity
2- Shape & composition of
projectile or Frontal area
3- Angle of impact
4- Flight characteristics as
yaw, tumbling & nutation
5- Fragmentation
6/15/2023 58
59. LOW VELOCITY BULLET
a. PART STRUCK SOFT AND ELASTIC TISSUE
b. PUSHES & STRETCHES THE SKIN & UNDERLYING TISSUE.
c. ROTATES UPON ITS AXIS
d. INDENTATION IS PRODUCED
e. PERFORATION OF TISSUE
f. PASSAGE OF BULLET
g. ENERGY OF BULLET RADIATES LATERALLY
h. DAMAGE PROPORTIONATE TO DIAMETER OF THE BULLET
i. REPRESENTED BY THE PATH OR TRACK OF THE BULLET
6/15/2023 59
60. SHOCK WAVES
I. DEMONSTRATED ONLY BY HIGH SPEED PHOTOGRAPHY OR RADIOGRAPHY
II. IN HIGH VELOCITY BULLETS
III. TRACK IS FORCED THROGH SOLID TISSUE.
IV. MEDIUM IS COMPRESSED BY MISSILE IN FRONT OF IT
V. REGION OF COMPRESSION MOVES AS A SHOCK WAVE OF SPHERICAL FORM,
4800/FT/S
VI. CHANGES OF PRESSURE REMAINS FOR A MILLIONTH OF SECOND BUT MAY REACH
PEAK VALUE UP TO 100atm.
VII. So damage at a distance from wound track.
VIII. Solid tissues like Muscle, Liver, Spleen & brain are very susceptible.
IX. Conducted particularly well along tube filled tubes like arteries & veins to
cause damage at a distance.
6/15/2023 60
61. Shock waves
…. generated in tissues by high velocity bullets, greater than 2,500/feet/sec
• Last only for 15-25 microseconds
• Are of high energy creating over 1000 lbs/sq inch of
pressure
• Easily rupture gas filled organs
6/15/2023 61
Shock Waves
62. Types of cavitations
Temporary:
Permanent:
High velocity missile
Main destructive effect
Release of energy, absorbed by the local tissue.
Accelerated violently forwards & outwards.
Continue to move even after passage of missile.
A large cavity is produced (temporary cavity), reaches its maximum size,
have sub atmospheric pressure, collapses in a pulsatile fashion and
permanent cavity left.
Soft tissues pulped, blood vessels disrupted and bone may be shattered.
6/15/2023 62
63. M/L Importance of Wound Ballistics
1- Recognition of Entry & Exit wounds
2- Distance of Fire
3- Direction of fire & Wound track
4- Relative position of weapon/victim & angle of fire
5- Cause of death
6- Manner of death
7- Identification of firearm
6/15/2023 63
64. Components of a Shot responsible for damage
1- Shot charge
(bullet/pallet)
2- Flame & heat
3- Hot explosive gases
4- Smoke
5- Wad
6- Unburnt gun powder
7- Grease from the barrel
6/15/2023 64
65. FIREARM WOUND COMPLEX
All these elements affect:
I. Body of the victim as signs & symptoms
II. At the place of strike or target produce
characteristic changes
Result is FIREARM WOUND COMPLEX
This has two components:
a. Wounding component
b. Non – wounding component
6/15/2023 65
66. Firearm-wound complex has four parts:
1. An entry wound
2. A track with its direction
3. Place of resting of bullet or shot-charge.
4. Exit wound
6/15/2023 66
67. ENTRY WOUND
SINGLE HOLE:
SIZE : depends upon skin elasticity, tail wag, explosive blast
effect of gases so either proportionate to the diameter of
the bullet, SMALLER or much larger having STELLATE SHAPE.
SHAPE: depending upon the angle of firearm with the
target. Circular, Oval, Elliptical, An elongated furrow.
Inverted margins. May be everted.
Collar of abrasion: shape depends upon the angle of firearm
with the target.
6/15/2023 67
72. 6/15/2023 72
Burning: Few inches in case of
revolver & one foot in case of a
Shotgun
by Naseeb R. Awan
Blackening: Absent after one
yard
by Naseeb R. Awan
73. Tattooing (due to unburnt gunpowder particles)
6/15/2023 73
Beyond 2 yards,
tattooing is not
present
by Naseeb R.
Awan
“ They pierce under the superficial skin layers causing
punctate abrasions of smaller blood vessels under the
skin “
75. Skin changes
Gross splitting: Seen in high velocity bullet & contact
wound of low velocity bullet . Tail wag/range/gas
penetration. BLOW BACK PHENOMENON
Bruising (at or around entry wound due to general tissue
trauma) MUZZLE IMPRINT, Gases of the blast ballooning &
bruising the skin/Vital reaction / Inflammatory reaction
Collar of Abrasion: Rub raw of the superficial skin layers
while projectile enters the skin. More prominent in rifled
firearms due to their rotational motion
6/15/2023 75
76. 6/15/2023 76
5/3/2004
40
Tail wag phenomenon
Medicolegal importance
Atypical firearm entry wounds
Bigger entry wound
X-shaped entry wound
Key hole or slit like entry wound
Multiple entry wounds of a single fire
Skin deep / muscle deep wounds
79. Classification of Firearm Rifled Entry wound
depending upon distance/range
6/15/2023 79
Contact entry
wound
Hard/Firm
contact
Loose contact
Close range: Up
to 2 yards
Near distant:
within six
inches
Intermediate
range:
1 – 2 yards
Distant range:
Beyond 2 yards
80. Contact Firearm Entry wound
• Muzzle of firearm pressed hard on some
hard bony area as forehead / skull
• Gases can’t enter skull & escape from sides
causing lacerations in the scalp
• Star shaped projections in scalp
• Components of shot present inside skull in
the track
6/15/2023 80
Stellate Firearm wound
81. FEATURES OF ENTRY WOUND
FIRM CONTACT
• Lacks exterior residue.
• No imprints of components of fire
externally.
• Burning, blackening, tattooing
present in the track or interior of
wound or on intervening bone.
• Pinkish discoloration due to
CoHb.
• Muzzle imprint on close
examination.
• Entry wound of variable shape
with collar of abrasion.
LOOSE CONTACT
As small gap between body &
weapon.
Circular defect.
Collar of abrasion.
Circular soot material.
Tattooing, blackening & burning
in the wound track.
No scorching, singeing
externally.
Muzzle imprint.
Pinkish discoloration
6/15/2023 81
82. Close Range Firearm Entry wound
• Examination of clothes is important
• Burning, blackening, tattooing present
• Collar of abrasion present
• Grease collar / Dirt collar may be present
• Margins may be inverted
• Wad maybe present in the track in case of smooth bored
firearm
6/15/2023 82
83. FEATURES OF ENTRY WOUND
NEAR DISTANT
Barrel is held close to skin in
the range of flame & smoke.
Central defect.
Collar of abrasion.
Inverted margins.
Burning, scorching, singeing,
blackening & tattooing
present.
INTERMEDIATE RANGE
• Within 1 – 2 yard
• Hole
• Collar of abrasion.
• Inverted margins.
• Blackening fades.
• Tattooing present
6/15/2023 83
84. FEATURES OF ENTRY WOUND:
DISTANT RANGE
• Hole
• Collar of Abrasion
• Grease collar inside the collar of abrasion also
called smudge ring
• No flame & gun powder effect.
6/15/2023 84
85. Shotgun Cartridge
• Construction:chamber primer/powder/wad/shot
• Shot types Bird, Buck, Slugs
• Pellets Rarely exit
• Variable factors
Range
Gauge
Choke
HIGH ENERGY TRANSFER
6/15/2023 85
86. 6/15/2023 86
SHOTGUNS
Shotguns: have a smooth bore; fire multiple pellets (can
fire single slug).
Construction:
a. chamber - encloses shotgun shell.
b. forcing cone - constricts the charge of pellets entering the
bore
c. the bore .
Gauge: measure of calibre of shotgun; number of lead
balls of the given bore diameter required to make up one
pound weight.
87. 6/15/2023 87
Shells (ammunition):
(a) tube - paper pre-1960 with mouth closed by "rolled
crimp"; plastic body or hull with mouth closed by "pie
crimp" or "star crimp", eliminating need for overshot wad.
(b) head - brass/brass-coated steel; low brass or high-brass
types depending on length.
(c) primer - see above.
(d) powder - see above.
88. 6/15/2023 88
(e) wads - four, viz: base (underpowder), overpowder, filler
(both between propellant and shot acting as gas seal),
overshot; Remington plastic "power piston" (1963) with four
"petals" replaced traditional felt or cardboard disc wads, other
manufacturers have similar designs;
must be recovered at autopsy since they indicate gauge of
weapon and bear manufacturers' marks; felt wads may swell
when wet, therefore measure after drying.
90. 6/15/2023 90
(f) lead shot - three types, viz. drop/soft shot (pure lead), chilled/hard
shot (lead hardened by antimony), plated shot (coated with
cupronickel), steel shot.
Two categories, viz. birdshot (for birds and small game), buckshot
(for large game).
slugs (for deer and bear in heavily populated areas).
Some become partially melted and fused by discharge gases and rapid
acceleration of pellets at bottom of the charge, others flattened by contact
with barrel; these distorted pellets become "fliers" straying from the main
pattern, veering off at varying angles.
white granulated polyethylene/polypropylene filler used in some loads
(produces pseudo-tattooing).
Sawn-off ballistic comparisons using "power piston" wad or sabot from
slug shotguns possible if sawed off barrel end has not been smoothed off.
97. Firearm Exit Wound
• There may be no exit wound
• May be multiple exit wounds of one entry wound due to
Secondary missiles
• May be large typical exit wound with everted margins
• No close range characteristics
• Shored exit wound: Collar of abrasion present
6/15/2023 97
5/1/2004
25
Bullet through a glass
Intermediate tail
wag
Secondary
misslies
Intermediate tail
wag
Secondary
misslies
98. Shot gun wounds
• Contact shotgun wound are most destructive
• Bursting rupture of head is rule rather than
exception
• Skull may be largely fragmented leading to
Egg-shell fractures
• Scalp is extensively lacerated
6/15/2023 98
“ The unfavourable ballistic shape of shotgun pallets combined
With lack of stabilizing spin, causes a rapid fall-off in velocity &
Thus Kinetic energy “ by Naseeb R. Awan
102. Entry Wound
• By contact to 2 ft birdshot
produces a single wound
• By 3 ft there will be Rat-hole
type of entry wound
• By 4 ft scattered satellite pallet
holes
• By 10 ft there is great variation
in type of entry wound
• The diameter of spread of
pallets on body in “inches “ is
roughly equal to the distance
from muzzle in “yards”
• Wad may travel upto 6 ft & may
be found in track of injury within
that distance
• Biliard Ball Ricochetting
phenomenon: Important in
giving distance of fire
6/15/2023 102
Shot gun Firearm wounds
103. This “cookie cutter” type wound shows a few
separate pellet injuries forming as the distance increases. This
is not a suicide.
6/15/2023 103
106. Important definitions
• Bone of skull is dipoc (has 2 layers).
• Table which is struck first by projectile is supported from
below so has comparatively small circular hole & clean
margins.
• Table which is 2nd to be struck has no support so has a
bigger irregular hole & beveled margins.
M/L importance
• Gives direction of fire
6/15/2023 106
Beveling of skull bone
109. Important definitions
• Birdshot
• Buckshot
• Dustshot
• Blank
ammunition
• Dum dum
bullets
Size of pallet is 2-9
Pallets larger than size 9
Pallets smaller in size
Only powder no projectile present
Either non-jacketed or partially jacketed.
They may expand or flatten on impact
thus increasing energy dissipation &
tissue destruction
6/15/2023 109
110. Important definitions
• Ballistic coefficient
• Fragmentation
• Embolised bullets
• Swallowed bullets
• Tandem bullets
• Ricochetted bullet
• Efficiency of a bullet in overcoming air resistance
• Breaking up of a jacketed bullet through some
bone or non-jacketed bullet through soft tissues
• Bullet gains access to blood circulation & carried
away to distant location
• Bullet that enters GI tract & carried away by
peristalsis
• Bullets remaining in barrel due to defect & then
come out subsequently one after the other
• Bullet which deviates from its course by striking an
intermediate object
6/15/2023 110
111. DUM-DUM BULLET
A hollow point is an
expanding bullet that has a pit
or hollowed out shape in its
tip, generally intended to
cause the bullet to expand
upon entering a target in
order to decrease penetration
and disrupt more tissue as it
travels through the target. It is
also used for controlled
penetration, where over-
penetration could cause
collateral damage (such as on
an aircraft).
6/15/2023 111
112. Tandem bullet
• Tandem cartridge if used could result in
multiple entrance wounds in a single fire.
• If the first bullet fails to leave the barrel and is
ejected by the subsequent fired bullets, The
bullets are ejected one before the other and
are called as tandem bullets.
6/15/2023 112
113. KENNEDY PHENOMENON
• Surgical alteration or suturing of gunshot
wounds creates problem. in this situation the
evaluation of the wound whether it was an
entrance or exit wound becomes difficult. This
phenomenon is called as Kennedy
phenomenon.
6/15/2023 113
114. 6/15/2023 114
BILLIARD BALL RECHOCHETTING
Diagnosing long-range injury based on the pattern of pellet spread is difficult.
When shotgun pellets are tightly clustered or widely spread out, close-range
injury or long-range injury (respectively) is usually suspected. However, in
close-range injuries, the billiard-ball effect may cause considerable pellet
spread.16
When the tightly clustered group of shot at close range contacts the skin, the
pellets at the front of the group are slowed. The pellets behind them in the
group strike the pellets in front, with an effect like a billiard-ball break.
This causes much more pellet spread in tissue than would be expected at
close range. On radiographs, particularly in trunk wounds, this effect can
simulate the pellet spread of a longer-range injury.16
Correlate the physical examination with the radiologic findings. If there is
only one entrance wound hole, it is a close-range injury. If the distribution of
the multiple skin entrance wounds is the same as the pellet spread on the
radiograph, the injury occurred at longer range.
