Firearm injuries

Question 1

In which part of the firearm are seen the spiral grooves that gives a rotatory motion to the projectiles?

Answer 1

Barrel

Question 2

how are called these grooves (2 names)

Answer 2

lands and grooves/

Question 3

2 types of handguns

Answer 3

Revolver
Pistol

Question 4

Caracteristics of assault rifles

Answer 4

Auto-loading
Large capacity detachable magazine (>20 rounds)
semi-full automatic

Question 5

Difference btw semi and full automatic fire

Answer 5

Semi: can rapidly fire if multiple trigger activation
Full: continuous firing while holding the trigger

Question 6

What is a submachine gun?

Answer 6

Full automatic fire
Designed to be fired from shoulder or hip
Riffled ammunition

Smaller than a machine gun

Question 7

2 types of powder

Answer 7

Black powder (charcoal, sulfur, potassium nitrate)

Smokeless powder (nitrocellulose colloided with nitroglycerine)

Question 8

2 ways to report calibre of bullet for riffles gun vs gauge for shotguns

Answer 8

Riffles:
Decimal of an inch (0.4 inch)
Millimiters (9mm)

Shotgun:
- number of lead balls of the inner diameter of the barrel that make up 1 pound in weight (commonest : 12 and 20)

Question 9

3 types of bullets

Answer 9

Non-jacketed
Semi-jacketed
Full metal jacketed (exposed lead base) / total metal jacket (entirely covered)

Question 10

3 types of shotgun ammunition

Answer 10

Birdshot
Buck shot
Slug

Question 11

What is the name of the piece of material that separate the shot/slug from the gunpowder in a shotgun ammunition

Answer 11

Wad

Question 12

What substance is found between buckshot pellets in shotgun ammunition?

Answer 12

Buffer material

Question 13

3 types of slugs

Answer 13

Brenneker (wad screwed to slug)
Foster (hollow cavity)
Sabot (hourglass apprearance)

But also:
- Rubber slug

Question 14

What is the temporary cavity?

Answer 14

Shockwave behind the bullet, causing extension of soft tissues

Question 15

Factors that affect temporary cavity (kinetic energy lost)

Answer 15

Amount of KE possessed by pullet at the time of impact

Angle of yaw of a bullet at the time of impact

Bullet characteristics

Density, strength and elasticity of the tissue struck

Question 16

Characteristics of entrance wounds

Answer 16

Abrasion collar (skin stretched before penetration –> not related to riffling, can also be present on gunshot wound entries)

Round circular defect

Soot or stippling

Question 17

Characteristics of exit wounds

Answer 17

Irregular
No abrasion collar
No soot/stippling

Question 18

When does exit wounds have an abrasion collar?

Answer 18

Shored exit

Question 19

How distinguish entrance vs shored exit wounds?

Answer 19

Shored exit:
- Larger and more irregular abrasion

Question 20

Different categories of range of fire

Answer 20

Contact (muzzle imprint, dirty wound tract)
Close range (usually < 15 cm, soot)
Intermediate (15 to 60-90 cm)
Distant (>60-90, intermediate target ruled out)
Indeterminate: can’t tell at autopsy (intermediate target, clothing)

Question 21

Characteristics of a contact wound

Answer 21

Dirty wound tract
Detachment of skin if on skull with radial lacerations (gas)
Muzzle imprint

Question 22

Difference between loose contact and close range

Answer 22

Loose contact: burning/charring of epidermis, but no soot

Close range: no burning/charring, but soot present

Question 23

What is the cylinder gap effect?

Answer 23

Due to the escape of some gases through the cylinder gap, may cause stippling or soot at areas where it is escaped

Question 24

Range of fire expected for shotgun wad abrasions around the entrance wound

Answer 24

2-3 feet (25 to 35 cm)

Question 25

Differences between handguns and rifles wounds

Answer 25

Handguns:
- Low energy
- Single wound tack
- Bullet often retained in body

Rifles:
- Higher energy
- Larger destructive wounds
- Larger defects
- Exit the body

Question 26

3 possibilites for jacketed bullet found in the body, without riffling marks

Answer 26

3d printed gun
Other handcrafted gun
Bullets that are fired during a fire

Question 27

1 ddx of soot around a wound

Answer 27

Nailguns

Question 28

What is an ARWEN?

Answer 28

Anti Riot Weapon Enfield