This powerpoint would provide a brief introduction to firearms and their medico-legal aspects

1. FIREARM INJURIES
(BALLISTICS)
Dr. A.K. Srivastava
Professor
Dept of Forensic Medicine
Subharti Medical College, Meerut

2. FIRE ARMS & AMMUNITION

3. CARTRIDGE

4. PARTS OF FIREARMS
 Barrel
 Breech part

5. Barrel
 Muzzle end
 Breech end
Lead, cone or taper
Chamber

6. BREECH PART
 Breech plate
 Lock incorporating firing pin
or striker
 Hammer (if any)
 Trigger
 Grip or butt

7. CARTRIDGE: Assembled ammunition
 Cartridge case
 Percussion cap
 Primer (detonator)
 Gun powder
 (propellant charge)
 Bullet / pellet
 (projectile or missile)

8. FIREARMS
“An instrument or devise
through which a projectile can
be propelled out by the
expansive force of gases
generated as a result of
combustion of propellant
charge in a closed space”

9. BALLISTICS
“Branch of Forensic Science
concern with the investigation
of firearms, ammunition and
the problems arising in their
use”

10. TYPES OF FIREARMS
 Small arms
 Heavy arms
It may be –
 Non automatic
 Semi-automatic (self loading)
 Automatic
Firearms are
 Smooth bored (Shot gun)
 Rifled gun

11. SMALL ARMS
 Hand gun
Revolver
Pistol
 Shoulder gun
 Mounted gun

12. REVOLVER

13. DRUM/ MAGAZINE

14. SMOOTH BORED GUN
 Muzzle loading gun
 Breech loading gun
Single barrel gun
Double barrel gun
Musket gun

15. RIFLED GUN

16. RIFLING
Parallel but spiral grooving in
barrel, usually one and half turn
from breech to muzzle end of gun
for passage of smoke and gases.

18. RIFLING
 Imparts gyroscopic stability
to bullet
 Helps to maintain a straight
trajectory and accuracy
 Prevents bullet from wobbling
 Gives greater power of
penetration and effective
range

19. BORE / CALIBER
Bore: Number of balls of equal
size, made from one pound
of lead and any one of ball is
exactly fitting at the muzzle
end of the gun

20. CHOKING OF A GUN
 Full choke gun
 Half choke gun
 Quarter choke gun
 Improvised cylinder
 True cylinder

21. TYPES OF CARTRIDGES
 Smooth bored
 Rifled
 Case less

22. PARTS OF A CARTRIDGE
 Cartridge case
 Percussion cap
 Primer
 Propellant charge
 Projectile
 Wad and cardboard disc (In
shot gun cartridge only)

23. PRIMER
It is made of –
 Potassium chlorate
 Antimony sulphide
 Lead styphnate
 Barium nitrate etc.

24. Propellant charge (gun powder)
 Black gun powder
 Smoke less gun powder
 Semi- smoke less gun powder

25. BLACK GUN POWDER
 Charcoal – 15%
 Sulphur – 10%
 Potassium nitrate – 75%

26. SMOKE LESS GUN POWDER
 Single base – Nitrocellulose
 Double base – Nitrocellulose +
Nitroglycerine

27. Semi- smoke less gun powder
 85% black gun powder
 15 % smoke less gun powder

28. PROJECTILES
 Bullet (Rifled gun)
 Pellets (shots)

29. WAD
 Separates projectile from gun
powder
 Seals the bore efficiently
 Prevent expansion of gases
 Allow optimum pressure to
develop

30. MAGAZINE
Spring loaded box or container
carrying a number of
cartridges

31. EFFICIENCY OF A GUN
Depends upon –
 Type of weapon
 Amount, nature & efficacy of
gun powder
 Projectile &
 Wad, which seals the barrel

32. Can be measured by –
 Muzzle velocity
 Pressure generated at the
breech end
 Range of fire
EFFICIENCY OF A GUN

33. Type of
Gun
Pressure
breech end
(Tons/Inch2
)
Muzzle
Velocity
(Mtr/Sec)
Range of
Fire
(Mtrs)
Shot Gun 3.5 to 5 300 30 - 40
Rifle 20 500 - 1000 600 - 1000
Revolver 6 200 50
Pistol 13 400 100

34. Physical Aspects of Firearm Injuries
 Loading (feed the cartridge)
 Cocking (pull the hammer)
 Firing (pull the trigger)

35. WOUND OF A FIREARM
Depends upon –
 Projectile
 Gun powder
 Flame & hot gasses (Burning)
 Smoke (Blackening)
 Un-burnt gun powder (Tattooing)
 Wads & cards (in shot-gun)

36. PROJECTILE
o Rifled gun: Single bullet &
single small hole in
wound of entry
wound of exit
o Shot gun: Multiple shots &
a large hole or
multiple small holes
in wound of entry

37. Range of Gun-powder effect
Around the wound, following
effects may be seen –
Gun Burning Blackenin
g
Tattooin
g
Revolver
or Pistol
2 - 3 inch 1 feet 2 feet
Rifle 6 - 8 inch 2 feet 2½ - 3 feet
Shot gun 12- 18 inch 3 feet 6 - 9 feet

38. WADS & CARDS
 Found in wounds – up to 6 feet
 May cause separate injury – 6 to
10 feet

39. INJURIES
produced by
FIREARMS

40. MEDICOLEGAL ASPECTS
 Is the wound caused by Firearm?
 If yes, type of firearm used?
 Is it a wound of entry or exit?
 Range and Direction of fire
 If wounds are multiple-
 Caused by one or more fire?
 Caused by one or more weapon?
 The time victim survived?
 Cause of death
 Manner of death

41. FIREARM WOUND
 Contused
 Lacerated
 Punctured wound
with some special modification
due to impact and entry of
missile and gun powder

42. CHARACTERISTICS OF WOUND
Depends upon –
 Type and bore of weapon
 Projectile used
 Gun powder
 Distance of fire
 Direction of fire
 Site of body
 Ricocheting effect

43. CIVILIAN INJURIES
These are usually due to –
 Single or double barrel shot gun
 Rifled gun
 Revolver
 Pistol
 Country made gun

44. INJURIES
produced by
A RIFLED FIREARM

45. WOUND OF ENTRY-BULLET
 Stretching of skin (abrasion collar)
 Penetration in skin (dirt / smudge
ring)
 Penetration into soft tissue & bone
 Skin partially return to original
position
 Burning effect
 Blackening
 Tattooing

46. WOUND OF ENTRY

47. ABRASION COLLAR

48. GUN POWDER EFFECT

49. Range of Gun-powder effect
Around the wound, following
effects may be seen –
Gun Burning Blackenin
g
Tattooin
g
Revolver
or Pistol
2 - 3 inch 1 feet 2 feet
Rifle 6 - 8 inch 2 feet 2½ - 3 feet
Shot gun 12- 18 inch 3 feet 6 - 9 feet

50. WOUND OF ENTRY
Depends upon:
 Range of fire
 Contact wound
 Close range wound
 Near range wound
 Distant range wound
 Velocity of bullet
 Wobbling of bullet

51. CONTACT WOUND
 Bigger with
lacerated margins
 No burning,
blackening or
tattooing
 Explosion effect

52. CLOSE RANGE WOUND
 Smaller size
 Key hole appearance
 Abrasion collar
 Dirt ring
 Scorching of skin
 Singeing of hairs
 Blackening
 Tattooing

53. NEAR RANGE WOUND
 Smaller size
 Key hole appearance
 Abrasion collar
 Dirt ring
 Blackening may present
 Tattooing may present

54. NEAR RANGE WOUND

55. DISTANT RANGE WOUND
 Abrasion collar
 Dirt ring
 No blackening or tattooing

56. DISTANT RANGE WOUND

57. EXIT WOUND
 Margins everted
 Bigger as compared to entry
wound
 Lead ring absent
 Burning, blackening and
tattooing absent
 More bleeding

58. EXIT WOUND

59. EXIT WOUND
It may not be present when bullet
is –
Inside the body
Coughed out
Vomited
Passed through fecal matter or
Dropped out through entry

60. WOUND IN SKULL BONE

61. WOUND OF ENTRY

62. EXIT WOUND

63. DIRECTION OF FIRE

64. SOME SALIENT POINTS
 Point blank range
 Tandem bullets
 Tandem Cartridge
 Dum-dum bullet
 Multiple wound of entry & exit
from a single fire

65. INJURIES
produced by
A SMOOTH BORED Firearm

66. SHOTGUN WOUND
It depends upon –
 Number & size of shots
 Dispersal of shots
 Wad and cards
 Distance (range)
 Unusual projectile
 Gun powder
 Choking of gun

67. DISPERSION OF PELLETS

68. CONTACT WOUND

70. MUZZLE IMPRINT

71. CLOSE RANGE WOUND

72. NEAR RANGE WOUND

73. NEAR RANGE WOUND

74. NEAR RANGE WOUND

75. DISTANT RANGE WOUND
 Each individual pellet produces
its own track
 The pellets only penetrate the
skin or muscle
 Injuries are usually simple,
mostly non-fatal

76. DISTANT RANGE WOUND

77. EXIT WOUND
 Usually no exit wound
 Rarely multiple exit wounds
when fired from contact or close
range with cartridge of bigger
shots
 Exit wound does not
corresponds with the site of
entry wound

78. OTHER QUARRIES
 How much time the victim
survived?
 Cause of death
 Manner of death