The document provides an in-depth overview of forensic ballistics, a science dealing with shootings to support justice, including concepts such as firearm identification and the various types of ballistics: internal, external, and terminal. It explains how firearms function, the characteristics of ammunition, the importance of identifying specific firearms through unique markings left on bullets and cartridge cases, and techniques used in forensic analysis. Advanced imaging technologies such as IBIS and BulletTrax-3D are detailed for enhancing the accuracy of bullet and cartridge case comparisons.

2.  “Ballistics is a branch of a applied mechanics
which is used to study motion of projectiles ,
missiles and associated phenomenon.”

3.  The term forensic ballistics was first coined
by colonel Calvin Goddard.
 “Forensic ballistic is a branch of science of
ballistics which deals the shooting incidence
for the purpose of justice.”

4.  Internal ballistics
 External ballistics
 Terminal ballistics

5.  Firearm
 Ammunition
 Target

6.  A firearm is a device or instrument which is
used to hurl a projectile or projectiles with a
great force in a particular direction.

7. A firearm means arm of any description designed or
adapted to discharge a projectile or projectiles of any kind
by the action of any explosives or other forms of energy ,
and includes:-
 Artillery , hand grenades , riot pistols or weapons of any
kind designed or adapted for the discharge of any noxious
liquid , gas or other such thing.
 Accessories for any such firearms designed or adapted to
diminish the noise or flash caused by the firing thereof.
 Parts of and machinery for manufacturing firearms and
cartridges , platforms and appliances for mounting ,
transporting and servicing artillery.

8.  Barrel
 Action
 Stock
 Firing pin or Striker
 Breech Face

9.  Chamber
 Extractor and Ejector
 Leed

11. The word ‘improvised’ indicates the
nature of the firearm.
 The improvised firearms, are also
known as country made firearms,
home made firearms , pipe guns, zip
guns.
 The country made are improvised by
the culprits from readily available
materials ,either personally or with the
help of a local blacksmiths.

12. Country made firearms have the usual parts-
 The barrel
 Chamber
 The action
 The lock

13. Firearms Identification -
The identification of fired bullets,
cartridge cases or other ammunition
components as having been fired from a
specific firearm.

14.  Firearm identification is a discipline mainly
concerned with determining whether a bullet was
fired by particular weapon.
 Class characteristics and Individual characteristics
plays very important role in the identification of
Firearm.
 When two metal species comes in contact with each
other the harder metal will always scrape the softer
metal. This leaves the evidence of the contact on the
both the pieces.

15. Firearms identification is actually a form of Toolmark
Identification where the firearm, because it is made of a
material harder than the ammunition components, acts as
a tool to leave impressed or striated marks on the various
ammunition components that come into contact with the
firearm.
Tool marks produced on the cartridge cases will be in
two basic forms.
Striated action marks
Impressed action marks

16. Principle of Identification
• “Every Contact Leaves a Trace”
EDMOND LOCARD

17.  A bullet when fired under high pressure
through a hand gun having rifled barrel
expands and fills the whole cross section of
the barrel.
 Marking of lands and grooves will be quite
visible in those cases where the bullet fills
the whole cross section of the barrel when
fired.

19.  In a fired Bullet, the Caliber, Number, Width,
Depth, Directions and Twist of Land and Grooves
form Class characteristics.
 The Finer striations in the land and grooves are
Individual characteristics of the Firearm.

20.  Class Characteristics: Once a manufacturer
chooses a rifling process, for a particular class
of weapon, they keep it consistent.
 Lands & Grooves are the same for a model.
› .32 caliber Smith & Wesson has 5 lands & grooves
twisting to the right.
› .32 caliber Colt has 6 lands & grooves twisting to the
left.
 Class characteristics can eliminate certain
makes but are not enough to ID a particular
gun.

21.  Imperfections in the manufacturing process
make each barrel unique.
 Rifled barrels, even if made in succession
will NOT have identical striation (scratch-like
marks).

23. The cartridges which are fired from automatic
and repeating firearms show repetitive marks
which are useful in identification of the type of
weapon used.

26.  A fired cartridge case contains:
i. Firing pin nose mark over the percussion cap.
ii. Breech face marks on the head of the CC
iii. Chamber marks on the wall of the CC
iv. Extractor marks on the rim surface &
extractor groove.
v. Ejector marks on the periphery of head of CC

28. striated action marks.
Scratches" are produced when the cartridge
case moves laterally against the tool (inner
surface of the firearm) producing a scrape
or striated mark.
Striated action marks are common to
cartridge cases that have passed
through the action of an auto loading or
repeating firearm.

29. Striated action marks include chamber marks;
shear marks, firing pin drag marks, extractor
marks, and ejector marks.

30. Chamber Marks
One of the most common striated action marks
are called chamber marks. Roughness in the
chamber of a firearm can scratch the outer walls
of a cartridge case when loaded and removed
from the chamber. Most chamber marks occur
after the cartridge is fired.
Cartridge cases expand when fired
pressing out against the walls of the
chamber. When they are pulled out of the
chamber, the sides of the cartridge case
can be scratched. The comparison image
below shows chamber marks on .22 calibre
,rim fire cartridge cases.

31. Chamber Marks

32. Chamber Marks

33. Shear Marks
Another common striated action mark are
shear marks produced by GLOCK pistols
on cartridge case primers. GLOCK pistols
have a rectangular firing pin hole (below)
in their breech face.

34. In a similar process, striated marks called firing pin
drag marks can be produced. When the firing pin
springs forward to strike the primer of a cartridge, it
may remain slightly forward and imbedded in the
primer. Certain barrels (like in the GLOCK) drop
down slightly as recoil is forcing the action open. The
cartridge case drops with the barrel causing the nose
of the protruding firing pin to drag across the primer
as it leaves the firing pin impression.
Firing Pin Drag Marks

35. The below comparison image shows firing
pin drag marks produced by a Colt 45 AUTO
pistol.

36. Another action mark, usually found in a striated
form, are those created by the extractor of most
auto-loading or repeating firearms. The extractor
is a small part sometimes resembling a hook that
is used to remove a cartridge or cartridge case
from the chamber of a firearm.
Extractor Marks

38. Ejector Marks
As described above, the extractor pulls the cartridge
case out of the firearm's chamber. As the cartridge
case is pulled to the rear it will be struck somewhere
on an opposing edge by a part as seen below called
the ejector.

39. Cartridge Case ejection

40. impressed action marks.
Impressed marks are created on cartridge cases
when it impacts the tool (again, the firearm) with
adequate velocity or pressure to leave an impressed
or indented mark.
Impressed action marks, with a few exceptions,
are produced when a cartridge case is fired in a
firearm.
Ejector marks can be striated in nature but a lot of
the time they are impressed action marks.

41.  Firing pin impressions
 Breech face marks

42. Firing Pin Impressions
Firing pin impressions are indentations created when
the firing pin of a firearm strikes the primer of center
fire cartridge case or the rim of a rim fire cartridge
case. If the nose of the firing pin has manufacturing
imperfections or damage, these potentially unique
characteristics can be impressed into the metal of the
primer or rim of the cartridge case.

45. Breech Marks
By far the most common impressed action marks
on cartridge cases are breech marks. Most fired
cartridge cases are identified as having been fired
by a specific firearm through the identification of
breech marks.
Very high pressures are generated within a firearm
when a cartridge is discharged. These pressures
force the bullet from the cartridge case and down
the barrel at very high velocities. When a firearm
is discharged, the shooter will feel the firearm jump
rearward. This rearward movement of the firearm
is called recoil.

47. To match bullets and cartridges to a gun, test bullets
must be fired through a suspect firearm for
comparison.

48.  Test bullets are the bullets which are fired
from the suspected firearm for the purpose
of comparison with the crime bullet.

49.  Variety of materials like rags, saw, soap, paraffin,
ice, water and cotton have been used in which test
firing is done to obtain test bullet. However the
most suitable material is water.
 The submitted firearm is fired in container filled
with water. Lid on tank is closed and lock and
muzzle of firearm is placed at open tube at end of
tank and fired. Friction of water slows down the
bullet they end up on the bottom of the tank about
halfway down its length.

50.  Firstly, visual examination is carried out with
ordinary light ,thrown at different angles .Then ,
 Stereoscopy
 Comparison microscope
 Borescope
 Comparison camera
 Striagraph
 Periphery camera
 Photographic comparison

52.  The comparison microscope consist of two
compound microscope mounted side by side
and connected by optical bridge. There are
two stages on the lower part of the microscope
that the bullets to be compared are mounted
on.
 Microscope used for firearm identification
have magnifications 5X, 10X, 20X, 30X, and 40X.

53.  The resulting image will show the bullets
mounted to the stages, side-by-side, with a
thin dividing line down the middle.
 The images below show rifling impressions
on a 32 caliber bullet at progressively
increasing magnifications.

54.  The stages that the bullets are attached to allow the
bullets being examined to be rotated on their axis
and moved up, down, to the left, and to the
right. The bullets are rotated around to see if any
microscopic similarities are present. Most positive
identifications are made on striations that occur in
land impressions and the best marks are usually
near the base of the bullets like those seen below.

55.  The comparison image below shows the above
bullet fragment (right) compared to a
standard (left) fired from the submitted
firearm.

58.  IBIS is a system that combines specially
designed imaging and correlation software
for acquiring and comparing the digital
image of bullet.
 3d- Brass Trax , 3d- Bullet Trax , Data
concentrator, Correlation server and Match
point all together forms IBIS

60.  A key feature of BulletTRAX-3D is its capacity to acquire
and preserve digital representations of the unique
microscopic striated marks (“lines”) produced in the
bearing surfaces of fired bullets. These include the land
engraved area (LEA, or land impression) and groove
engraved area (GEA, or groove impression).
 Typically the most useful details are found closest
to the base of fired bullets, as the area last in contact with
the barrel, and typically least subject to damage. Of these
the most useful are usually found in the LEA.
BulletTRAX-3D acquires this image data by integrating
the use of a number of specialized components.

62.  The latest three dimensional sensory
technology that allows 2D digital images to
created 3D topographic models of bullet
surface area.

63.  Bullet Trax allows to capture the high quality
images of cartridge cases in both 2D and 3D
and offers greater impression detail and
multiple viewing perspectives.
 It provides a number of quality control
features such as an automated acquisition
tray, automated imaging for breech face and
firing pin impressions, and automated
lighting, focus, and system calibration.

65.  The Correlation Server is the engine that
propels the comparison functions of IBIS
technology.
 The Correlation Server receives, manages,
and compares the unique digital signatures
taken from the images of ballistic exhibits.

66.  IBIS MATCHPOINT provides the ability
to compare digital images in side-by-side or
multi-viewing modes.
 It also helps in making more accurate
comparison calculations. It analyzes bullet
in both two dimensions and three
dimensions.

68.  When comparisons are made between evidence and standard
bullet the results can read as follows:
1. The bullet was identified having being fired from firearm.
 This conclusion is reached after all class characteristics agree and
a sufficient correlation between individual characteristics is found.
2. The bullet could neither be identified nor eliminated as having
been fired from firearm. All comparisons were inconclusive.
 This conclusion is reached if class characteristics agree but there is
an insufficient correlation between individual characteristics.
3. The bullet was not fired from Firearm.
 This conclusion is reached if class characteristics disagree.