Firearm injuries Flashcards
In which part of the firearm are seen the spiral grooves that gives a rotatory motion to the projectiles?
Barrel
how are called these grooves (2 names)
lands and grooves/
2 types of handguns
Revolver
Pistol
Caracteristics of assault rifles
Auto-loading
Large capacity detachable magazine (>20 rounds)
semi-full automatic
Difference btw semi and full automatic fire
Semi: can rapidly fire if multiple trigger activation
Full: continuous firing while holding the trigger
What is a submachine gun?
Full automatic fire
Designed to be fired from shoulder or hip
Riffled ammunition
Smaller than a machine gun
2 types of powder
Black powder (charcoal, sulfur, potassium nitrate)
Smokeless powder (nitrocellulose colloided with nitroglycerine)
2 ways to report calibre of bullet for riffles gun vs gauge for shotguns
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)
3 types of bullets
Non-jacketed
Semi-jacketed
Full metal jacketed (exposed lead base) / total metal jacket (entirely covered)
3 types of shotgun ammunition
Birdshot
Buck shot
Slug
What is the name of the piece of material that separate the shot/slug from the gunpowder in a shotgun ammunition
Wad
What substance is found between buckshot pellets in shotgun ammunition?
Buffer material
3 types of slugs
Brenneker (wad screwed to slug)
Foster (hollow cavity)
Sabot (hourglass apprearance)
But also:
- Rubber slug
What is the temporary cavity?
Shockwave behind the bullet, causing extension of soft tissues
Factors that affect temporary cavity (kinetic energy lost)
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
Characteristics of entrance wounds
Abrasion collar (skin stretched before penetration –> not related to riffling, can also be present on gunshot wound entries)
Round circular defect
Soot or stippling
Characteristics of exit wounds
Irregular
No abrasion collar
No soot/stippling
When does exit wounds have an abrasion collar?
Shored exit
How distinguish entrance vs shored exit wounds?
Shored exit:
- Larger and more irregular abrasion
Different categories of range of fire
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)
Characteristics of a contact wound
Dirty wound tract
Detachment of skin if on skull with radial lacerations (gas)
Muzzle imprint
Difference between loose contact and close range
Loose contact: burning/charring of epidermis, but no soot
Close range: no burning/charring, but soot present
What is the cylinder gap effect?
Due to the escape of some gases through the cylinder gap, may cause stippling or soot at areas where it is escaped
Range of fire expected for shotgun wad abrasions around the entrance wound
2-3 feet (25 to 35 cm)
Differences between handguns and rifles wounds
Handguns:
- Low energy
- Single wound tack
- Bullet often retained in body
Rifles:
- Higher energy
- Larger destructive wounds
- Larger defects
- Exit the body
3 possibilites for jacketed bullet found in the body, without riffling marks
3d printed gun
Other handcrafted gun
Bullets that are fired during a fire
1 ddx of soot around a wound
Nailguns
What is an ARWEN?
Anti Riot Weapon Enfield
