FORENSIC

BALLISTICS
INTRODUCTION TO
FIREARMS
IDENTIFACATION
Ballistics
Ballistics
 A science that deals with the
motion of projectiles.
Legal meaning:
 It is the microscopic examination of
fired cartridge cases and bullets
together with the recording and
presentation by means of photography
of what is revealed by the microscope.
Origin
 It was derived from the Greek word
“ballo” or “Ballien” which means “to
throw”.

 It root was said to be derived from the

Roman weapon “ballista”.
The largest gun

The Gustav gun

The smallest gun
■The Swiss Mini Gun
(KOLIBRE) is the size of a key
fob but fires tiny 270mph
bullets powerful enough to kill
at close range.
■Officially the world's smallest
working revolver, the gun is
being marketed as a collector's
item and measures just 2.16
inches long (5.5cm).
THE BRANCHES
OF BALLISTICS
INTERIOR BALLLISTICS
■refers to the motion of projectiles
while it is inside the firearm.
INTERIOR BALLLISTICS
■ This extends from the breech to the
muzzle of the firearm.
■ The primary effort of interior
ballistics is to study the effect of the
propelling charge, during and after
burning, upon the projectile.
BALLISTICS PENDULUM
by Benjamin Robins
■Charles Hutton – developed a formula
for the velocity of a spherical projectile.
■Gen. Thomas Jackson Rodman – in 1857
led to improvements in the grain-form
of powder and in the manufacture of
guns. He also devised a gauge for the
direct measurement of the maximum
pressures of powder gases in guns.
■Paul Vieille – introduced smokeless
powder.
 FICEPERVRE
■ Firing pin hitting the primer
■ Ignition of the priming mixture
■ Combustion of the gunpowder
■ Expansion of the heated gas
■ Pressure developed
■ Energy generated
■ Recoil of the gun
■ Velocity of the bullet inside the barrel
■A. Firing pin hitting the primer
B. Ignition of the priming mixture and
Combustion of gun powder
D. Expansion of heated gas
D. Recoil is the backward momentum of a gun when it is
discharged.

E. Pressure developed – measured in pounds per square

inch (lbs. / sq. inch or psi)

F. Velocity of the bullet – measured in feet per second

(ft./sec.)

G. Energy Generated

H. Rotation of the Bullet

I. Engraving of the cylindrical surface of the bullet.

EXTERIOR BALLISTICS
- refers to the motion of projectiles
from the time it leaves the muzzle of
the firearm and reaches the target.
A. Muzzle blast – the sound created at
the muzzle and of the barrel of the
firearm after explosion
Muzzle Energy
■ The kinetic energy of a bullet as it is
expelled from the muzzle of a
firearm. It is often used as a rough
indication of the destructive
potential of a given firearm or load.
The heavier the bullet and especially
the faster it moves, the higher
its muzzle energy and the more
damage it will do.
 Trajectory – is the actual pattern or
the curved path of the bullet in flight.
D. Gyroscopic action – is
the spinning motion of the
bullet while in flight
RANGE – the distance between the firearm
and the target.
Effective Range - The maximum distance
at which a weapon may be expected to be
accurate and achieve the desired effect.
Maximum Range – the greatest distance a
projectile can travel when fired at the
optimum angle of elevation of the barrel.
Velocity – the speed of the
bullet
Chronograph - is an instrument used to measure
the velocity of a projectile fired by a gun
G. Air resistance – encountered by the
bullet in flight.

H. Pull of gravity – the downward

movement of the bullet.
STABILIZATION OF
PROJECTILE
■ Two methods are used to stabilize
projectiles and obtain the desired
type of flight: spin and fins.
TERMINAL BALLISTICS
■ It is a branch of science that deals with
the effects of the impact of the projectile
on the target.
■ It is the study of how a projectile
behaves when it hits its target and
transfers its kinetic energy to the target.
■ It is concerned with the forces operating
at the end of the projectile’s trajectory,
that is, at the target..
A. Terminal accuracy – the size of
the bullet grouping on the
target.

B. Terminal energy – energy of

the bullet.
D. Terminal penetration – the
depth of the bullet on the
target.
 Means of Producing
■ Damage
Fragmentation – the action of relatively small particles,
usually from the case of a bomb or racket.
■ Impact – pertains to the penetration or perforation of an
object by a relatively large metallic body, such as an
armor-piercing shot.
■ Blast – release of energy in shock waves.
■ Debris – set in motion at high velocity.
■ Heat – the flame in front of the blast.
■ Fire – from the effects of an explosive or induced by
special incendiary weapons.
■ Chemical action
■ Bacteriological action
■ Radioactivity
Terminal Ballistics
(Hitting the Target)
■ Tumbling has a lot to do with the injury pattern of a
bullet on the target.
■ A short, high velocity bullet begins tumbling more
rapidly in tissue. This causes more tissue to be
displaced and imparts more of the KE to the target.
■ A longer, heavier bullet might have more KE at a
longer range when it hits the target, but it may
penetrate so well that it exits the target with much
of its KE remaining.
■ The speed the projectile must travel to penetrate
skin is 163 feet per second and to break a bone is
213 fps
 Round
Nose
Bullet
Provide the least
breaking, usually
jacketed, and
useful mostly in
low velocity
handguns.
Wadcutte
r
(Flattene
 the bullet’s
d)design provides
the most
braking from
shape alone, is
not jacketed,
and used in low
velocity
handguns.
Semi-
wadcutte
r
Hollow Point Bullet
FORENSIC BALLISTICS

 Is the study of firearm

identification by means of the
ammunition of fired through
them.
 This involves the investigation
and identification of the firearms
by means of ammunitions fired
through them.
Stages of Forensic
Ballistics
 Field Investigation
 Refers to the work of an investigator
in the field.
 It concerns mostly with the collection,
markings, preservation, packing and
transmission of firearms evidences.
 It includes the study of class
characteristics of firearms and bullets.
Stages of Forensic
Ballistics
 Technical Examination
• Refers to the examiners who examine
bullets and/or to determine also whether
or not cartridge cases were loaded or
ejected from the suspected firearm
submitted.
• Reports are made by the examiners and
testify in court regarding their report.
Stages of Forensic
Ballistics
 Legal Proceeding/Court
Presentation
 Presentation of Ballistics reports,
firearm, bullets, cartridges cases
and allied exhibits in the court.
 Appearance of the examiner in court
as an expert witness.
 HISTORICAL
TIMELINE OF
FIREARMS
IDENTIFICATION
(FORENSIC
BALLISTICS)
FIREARMS
Legal definition of
firearm
Section 877of revised Administrative code and section
290 of National Internal Revenue;
“firearms or arms include rifles, muskets,
carbines, shotguns, pistols, revolvers, and all
other deadly weapons from which bullets,
balls, shots, shells, or other missiles may be
discharged by means of gunpowder or other
explosives. The barrel of any firearm is
considered a complete firearm for all intents
and purpose thereof”.
Classes of firearms
TYPES OF FIREARM
ACCORDING TO IT’S
CALIBER
 Artillery

those that propel projectile more than one inch in diamet

 Small arms

-those that propel projectiles less than one inch in diame

Type of Hand Gun
Pistols

- A handgun with a chamber

that is integral with the
barrel.
 ‘

Revolver

-a hand gun that has

a cylinder containing multiple
chambers and at least one
barrel for firing.
Types of F.A’s (according to it’s
Barrel)
 Rifle
(shoulder arms)

- A firearm having barrel with a spirally grooved

interior, which
imparts to the bullets spinning motion and thus
greater accuracy over a longer range.
 Shotgun

-are firearms typically fired from the shoulder that are

designed to fire shot shells containing anywhere from
one large projectile to as many as several hundred small
pellets.
 Types of F.A’s
(according
1. Single Shots
to
mechanical
2. Repeated Arms
construction)
 Single shot

--firearms that hold only a single round of ammunitio

and must be reloaded after each shot.
Repeating Arms

■ Type of firearm designed to fire several shot in one

loading
■ Bolt action type
■ Automatic loading type
■ Pump action type
■ Lever action type
Automatic Loading Type

After the first shot is fired, automatic loading or

feeding of the chamber takes place.
 Pump/slide Action type

-is one in which the handgrip can be pumped back and forth
in order to eject a spent round of ammunition and to
chamber
a fresh one.
 Bolt Type

-a type of firearm action in which the weapon’s bolt is operated

manually by the opening and closing of the breech (barrel) with a
small handle, most commonly placed on the right hand side of the
weapon (for right-handed users).
 Lever Type

-is a type of firearms action which uses a lever located around

the trigger guard.
Type of F’A According to
its Action
■ Single Action – the trigger perform a single action
and that to release the hammer which contact with
the firing pin and discharge the primer which ignite
the powder charge
■ Double action- the trigger can both cock and
release the hammer.
Definition of
Ammunition
(legal and technical)
 legal definition of Ammunition--- A loaded
shell for
rifles, muskets, carbines, shotguns, revolvers
and pistols from which a ball, bullet, shot,
shell or other missile may be fired by
means of gunpowder or other explosives.
Technical definition of Ammunition--- refers
to group of cartridge or a single unit or
single cartridge – meaning a complete
unfired unit consisting of a bullet, cartridge
case, gunpowder and primer.
Ammunition
Components
1.Cartridge case
2.Primer
3.Propellant
4.Projectile
PARTS OF THE
CARTRIDGE
 Bullet

Bullet-the projectile propelled through the barrel of a firearm by means of

Force of gasses coming from the burning gun powder.
 Cartridge case

artridge case-the tubular metallic container which hol

ogether the propellant, gun powder, projectile and th
rimer.
 Gun powder

un powder- the powder charge which, when ignited

y the primer’s flash, is converted into heated gas
nder high pressure and propels the bullet or shot char
hrough the barrel and to the target .sometimes called
ropellant r powder charge.
Gunpowder

 Types of gun powder

1.Black Powder- produces large amount of greyish
smoke and leaves a considerable residue in the
gun barrel.
2.Smokeless Powder- a misnomer for it is neither
smokeless nor in powder form. Almost all
smokeless powder grains have perfectly definite
shape.
Black Powder
Smokeless Powder
 primer

Primer- the metal cup containing the highly sensitiv

priming compound which when struck by the firing
pin would ignite. Such action is called” Percussion”
According to the
location of the
primer:
■1.pin fire
■2.rim fire
■3.center fire
 PIN FIRE-

is an obsolete type of metallic firearm cartridge in which the priming

compound is ignited by striking a small pin which protrudes radially
from just above the base of the cartridge.
Rim fire
Centerfire
classification of
cartridges
(according to the base
form)
Rimmed-the rimmed cartridge is the oldest of the types and has
a rim that is significantly larger in diameter than the base of the
cartridge. rimmed cartridges use the rim to hold the cartridge in the
chamber of the firearm, with the rim serving to hold the cartridge at
the proper depth in the chamber.
Semi-rimmed- the rim project slightly beyond the base
of the case, though not as much as a rimmed
cartridge
Rimless-the rim is the
same
diameter as the base of
the case.
 TYPES OF BULLETS

■ Armour Piercing
■ Frangible or fragmented
■ Dum dum bullet
■ Incendiary bullet
■ Tracer bullet
 Armour piercing bullet

-A bullet constructed of hardened material or carrying a hardened

core specifically designed to penetrate bullet resistant, or armour
plated targets such as tanks and other vehicles.
Frangible bullet

-the disruption of the bullet into many pieces

caused by the forces of impact on the bullet.
Expanding bullet or Dum
Dum bullet

- Have a metal jacket open at both ends

so they flatten on contact with living
tissue and produce great internal
damage
Incendiary bullet
is a form of shell which combines
armour-piercing capability and a high
explosive effect
Tracer Bullet
Bullet Caliber
1. Caliber: the diameter of the gun barrel.
2. Caliber is recorded in
– hundredths of an inch (.22
& .38)
– millimeters (9mm)
Firearms Evidence

Individual Characteristics: Class Characteristics:

1.Firing pin marks 1.Bullet type
2.Breech marks 2.Bullet caliber
3.Extractor marks 3.Bullet weight
4.Ejector marks 4.Lands and grooves
5.Chamber marks 5.Rifling
6.Cartridge case
7.Head stamp
Bullet Comparisons

1. Each gun leaves distinct markings on a bullet passing

through it.
2. A gun barrel is made from a solid bar of steel that has
been drilled/hallowed out.
3. The drill leaves microscopic marks on the barrel’s inner
surface.
4. Gun manufacturers also add spiral grooves to the barrel.
This is known as rifling.
5. Lands: the space between the grooves.
6. As a spinning bullet passes through the barrel, it is
marked by these grooves
 Rifling
1. The grooved spirals inside the barrel of a gun that
produce lands and grooves on a bullet

2. Lands & grooves are class characteristics

Class Characteristic
Class characteristics
according to riflings
Styr type – 4-R-G=L
Smith & Wesson type - 5-R-G=L
Browning type – 6-R-G2x
Colt type – 6-L-G2x
Webley type – 7-R-G32x
Army type – 4-R-G3x
Individual Characteristic

■ Are those characteristic markings peculiar in

character and which are not found in all other
firearm.
■ They serve as basis to identify a particular firearm.
Cartridge Markings

1. Cartridge Case Individual Characteristics:

– Breech face marks
– Firing pin impressions
– Chamber marks
– Extractor marks
– Ejector marks
BREECH FACE
Breech Marks
1. When a cartridge is fired, the explosion forces the bullet
down the barrel and the shell casing is forced back against
the breech.
2. This leaves impressions unique to the individual gun’s
breech on the shell casing
Breech face Marks
FIRING PIN
 Firing Pin Marks
1. In order to fire the
cartridge, the primer
must first be ignited. To
accomplish this a firing
pin strikes the center
ring of the cartridge.
2. This will in turn leave a
distinct impression that
is unique to the firing
pin of that particular
gun.
CHAMBER
Chamber

■ is the portion of the barrel or firing cylinder in

which the cartridge is inserted prior to being
fired. Rifles and pistols generally have a single
chamber in their barrels, while revolvers have
multiple chambers in their cylinders and no
chamber in their barrel. Thus rifles and pistols can
usually be fired even with a detached magazine,
while a revolver has a separate chamber.
Chamber Marks
EJECTOR

the mechanism that after firing throws out the empty

cartridge or shell.
Ejector Marks
EXTRACTOR

is a part in a firearm that serves to remove brass

cases of fired ammunition after the ammunition has
been fired. When the gun's action cycles,
the extractor lifts or removes the spent brass
casing from the firing chamber.
EXTRACTOR MARKS
QUESTIONS?