DiMaio Ballistic Wounds

Question 1

4 main parts of a gun

Answer 1

Grip
Trigger
Hammer
Barrel

Question 2

What happens when the trigger is pulled?

Answer 2

Hammer strikes the firing pin against the base of the cartridge, igniting the primer, followed by the main powder charge that propels the bullet down the barrel

Question 3

What are the 2 types of primer in cartridges of rifles and handguns

Answer 3

Rimfire ammunition (rim of the base)
Center-fire ammunition (center of the base)

Question 4

What is “rifling”

Answer 4

Series of parallel spiral grooves and lands on the bore (interior of the barrel) which impart a rotational spin on the bullet as it travels down the barrel

Question 5

What usually determines the caliber of a gun

Answer 5

Diameter of the bore

Question 6

Difference between ammunition and cartridge

Answer 6

Cartridge = type of ammunition

Question 7

Main parts of a cartridge

Answer 7

Bullet/projectile
Propellant
Primer
Casing

Question 8

3 types of low-velocity riffled gun

Answer 8

Pistol
Revolver
Rimfire rifles (long gun)

Technically, shotgun is also a low-velocity firearm, but not riffled

Question 9

Main elements that affect kinetic energy of a projectile

Answer 9

1/2 x mass x velocity^2

Question 10

3 ways a bullet create injuries

Answer 10

Shredding and crushing by the bullet itseld
Compression, stretching and shearing 2nd to temporary cavity
Secondary injuries due to breakup of the bullet

Question 11

Explains what is the pathological range of fire

Answer 11

When a firearm is discharged, heat and flame, soot, unburned/burnt gunpowder and the bullet are ejected.

These substances can mark the skin of the clothing depending on the distance between the firearm and the body. When we identify these, we can give a pathological range of fire.

The main categories of range of fire are:
- Contact
- Close
- Intermediate (powder tattoo or stippling)
- Undetermined

Question 12

Elements of a contact wound

Answer 12

Can be divided into:
- Loose contact:
- Hard contact: muzzle tightly held against the skin, so all material in the wound (but searing and soot on immediate edge of the wound

Question 13

T or F: caliber of the bullet can be determined by the diameter of the entrance wound

Answer 13

FALSE: due to diameter of the bullet but also elasticity of the skin and location of the wound

Question 14

3 substances that can be tested in gunshot residue

Answer 14

Lead, antimony, and barium