Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Forensic MBBS > Ballistics > Flashcards

Ballistics Flashcards

1
Q

Types of ballistics

A
  1. Internal ballistics
  2. External ballistics
  3. Terminal ballistics
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Rifled firearm

A
  1. Cross section: lands and grooves
  2. Fired as a single bullet
  3. No contact with each other on firing
  4. Composed of lead
  5. Rotation present ➡️ increase in:
    • velocity
    • energy
    • gyroscopic moment
    • range
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Caliber of a rifle

A

Distance between 2 opposite lands in the cross section of a rifle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Smooth bore weapon

A
  1. Smooth Internal surface
  2. Pellets strike each other
  3. Composed of lead, antimony
  4. Rotation absent: less velocity, range
    Example:
    shot gun - 40-50 yards
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ranges of rifles

A

Revolver: 200
Pistol: 400
Military rifle: 1000-3000
In yards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Modifications of smooth bore weapon

A
  1. Choking:
    Funnel shaped muzzle ➡️ reduce dispersion of pellet
  2. Paradoxing:
    Terminal part has lands and grooves
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

12 and 24 bore gun

A

In a 12 bore gun, lead sphere of 454 gm is equally divided into 12 pellets
Similarly is for 24 bore gun

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Cartridge of a rifled firearm

A

The trigger removes the detonator cap,

When primer is ignited (friction) ➡️ gun powder burns ➡️ pressure increases ➡️ bullet fired (or pellets)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cartridge of a smooth bore weapon consists of

A
  1. Pellets
  2. Felt wad - lubricant
  3. Gun powder
  4. Card board disc
  5. Detonator cap or percussion cap: Cu or Zn
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Composition of primer

A

B. Barium nitrate
L. Lead
As. Antimony Sulfide
T. Tetracene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Types of gun powder

A 
1. Black gun powder:
 KNO3 - 75% oxidising
 Charcoal - 15% binding
 Sulphur - 10% fuel
2. Smokeless gun powder: better
 • single base - nitrocellulose NC
 • double base - NC + nitroglycerin NG
 • triple base - NC + NG + nitroguanidine
3. Semi smokeless gun powder:
 20% smokeless 
 \+ 80% black gun powder
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Types of black gun powder

A

Fg, FFg, FFFg
F - fineness
More the number of F, faster is the burning of the powder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Tests for detection of gun powder

A

H. Harrison Gilroy test
A. Atomic absorption spectroscopy
N. Neuron activation analysis
D. Dermal nitrate test/ paraffin test- not used
SEM-EDXA Scanning Electronic Microscope - Energy Dispersive X-ray Analysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Bullets are picked up by

A

Hand (with gloves🧤) and not by any other instrument to preserve markings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Markings of a bullet

A 
1. Primary markings:
 Decides class
 Decided by manufacturing company 
2. Secondary marking:
 Individual irregularity of weapon barrel
 Bullet fingerprint
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Types of bullet

Part 1

A 
1. Dum Dum bullet: maximum damage
 Terminal end broken/ chiseled out ➡️ explodes
 Sometimes jacketed
2. Express bullet: high velocity
 Base has a hole
3. Tracer bullet:
 Release powder throughout is course
4. Incendiary bullet: contains phosphorus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Types of bullet

Part 2

A
  1. Frangible bullet: fragments
  2. Glancing bullet:
    Grazes objects causing gutter fracture
  3. Souvenir bullet:
    Restrained billet lodged in bone or soft tissue
    Lead poisoning
  4. Ricochet bullet:
    Oblique entry wound
18
Q

Types of bullet

Part 3

A 
9. Yawning bullet: slow and irregular
 Keyhole shaped entry wound 
10. Tumbling bullet: tumbles on end
11. Tandem bullet: piggyback bullet 
 Two bullets fired simultaneously
 Second bullet pushes the first
12. Plastic bullet: Baton bullet
 PVC
19
Q

Billiard ball effect

A

Pellets when they strike each other

20
Q

Tandem cartridge

A

Single cartridge having 2 bullets ➡️ 2 entry wounds

21
Q

Differences between entry and exit wound for both rifles and shotguns

A
  1. Size: entry - small
    exit - large (except point blank)
  2. Margin: entry - inverted
    exit - everted
  3. Tissue discolouration only in entry wound - cherry red (CO from smoke and Hb)
  4. Singing, blackening and tattooing are seen only entry wound
  5. Skull bone bevelling
22
Q

Features of an entry wound specific to rifle

A 
1. Grease collar:
 Due to lubricant surround the entry wound
2. Abrasion collar:
 Surrounding the grease collar
 Decides the direction of the bullet
23
Q

Shape of entry wound of a shotgun

A 
Contact shot: stellate or cruciate
O. Oval/ circular: 0 - 1m
R. Rat hole: 1 - 2m 
 Indented margins
S. Satellite: 2 - 4m
 Major entry wound surrounded by many minor wounds
Distant: more than 4m
 Individual pellet entry wounds
24
Q

Features of a point blank shot

A

Entry wound:
Larger
Satellite or cruiciate shape
Muzzle markings may be seen

25
Q

Singing, blackening and tattooing

A 
In the order of disappearance with distance:
1. Singing/ burning of hair - flame
2. Blackening - smoke of gun powder
3. Tattooing - unburnt gun powder
Present along the track
26
Q

Ranges of different types of guns wrt presence of SBT, BT and T in inches

A
  1. Pistol and revolver: 3, 6, 12-18
  2. Rifles: 6, 12, 24-36
  3. Shot guns: 12, 24, 48-72
    in inches
27
Q

Bevelling of skull bone

A

Skull bone bursting at the exit point (not exit ‘wound’)
Bevelling in entry ➡️ inner table
Bevelling in exit ➡️ outer table

28
Q

Kennedy phenomenon

A

After surgery it becomes difficult to identify entry or exit wound

29
Q

Puppe’s rule

A

It helps to determine the sequence of skull fracture

When two fracture lines meet at same point, then the second fracture line never crosses the first

30
Q

Helixometer

A

Instrument used to decide the dimension of a weapon

31
Q

Primer in ballistics

A

Mercury fulminate

32
Q

Only weapon which never ejects cartridge

A

Revolver

33
Q

Butterfly fracture

A

Fracture of tibia by firearm injury

34
Q

Gyrojet cartridge

A

Used for rockets

35
Q

RDX

A

Research Departmental Explosive

36
Q

Carbine

Musket

A

Carbine- Rifled firearm

Musket- smooth bore firearm

37
Q

Rayalaseema phenomenon

A

In stab injury bullet is implanted to mislead the investigation

38
Q

Kronlein shot

A

Contact shot causes skull bursting

39
Q

Petrol bomb

A

Molotov cocktail

40
Q

Metal fouling

A

Small lesions surrounding the entry wound due to metal discharge from interior of barrel

41
Q

Range of weapon based on choking

A
  1. Fully choked weapon (yards): dispersion of pellets (inches) * 3/4
  2. Half cooked weapon (yards): dispersion of pellets (inches)
  3. Cylinder bore gun (yards): dispersion of pellets in inches * 1.5

Forensic MBBS (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions