Interior ballistics is a subfield of ballistics in which there is study of the propulsion of a projectile. In guns internal ballistics covers the time from the propellant's ignition until the projectile exits the gun barrel. The study of internal ballistics is important to designers and users of firearms of all types, from small-bore rifles and pistols, to high-tech artillery.
Interior ballistics is a subfield of ballistics in which there is study of the propulsion of a projectile. In guns internal ballistics covers the time from the propellant's ignition until the projectile exits the gun barrel. The study of internal ballistics is important to designers and users of firearms of all types, from small-bore rifles and pistols, to high-tech artillery.
introductory information related to the field of firearms identification; the evidences, the principles involeved in their examination and the categories of guns.
Explanation of ballistics, various fields of ballistics, Forensic Ballistics,Firearms and its components, Ammunition and its components, firing mechanism of firearm, Identification & individualization.
Forensic Ballistics is a branch of forensic science which deals with shooting incidents for the purpose of justice. Matching and identification of cartridge cases and bullets plays a key role in identifying the firearm.
introductory information related to the field of firearms identification; the evidences, the principles involeved in their examination and the categories of guns.
Explanation of ballistics, various fields of ballistics, Forensic Ballistics,Firearms and its components, Ammunition and its components, firing mechanism of firearm, Identification & individualization.
Forensic Ballistics is a branch of forensic science which deals with shooting incidents for the purpose of justice. Matching and identification of cartridge cases and bullets plays a key role in identifying the firearm.
This presentation illustrates different threat modes such as guns, ammunition and armours. The damage effect of bullets of different calibers are shown here. Development of armours and its types are discussed. This presentation gives a qualitative and quantifiable idea of threats and protect military had to deal with, while in operation
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
1. FORENSIC BALLISTICS
By: KEISHA ALYSSA R. BRILLO, RC
3rd Placer, October 2016 Criminologists Licensure Examination
Cum Laude, Emilio Aguinaldo College-Manila
2. BALLISTICS
•It is the science of motion of projectile
and the condition governing that
motion. The word “Ballistics” was
originated from the Greek word “Ballo”
or “Ballein”.
3. • Ballo or Ballein means to throw and from a Roman war
machine called “Ballista”.
• Ballista-a gigantic bow or catapult used throw missiles
and large objects such as stones at a particular distance
to deter animal or enemy forces. From those words the
term Ballistics was derived to indicate the science of
moving projectile.
5. MOTION
•In relation to ballistics, it refers
to the movement or mobility
of the projectile from one
point to another.
6. TYPES OF MOTION (DTR)
•Direct – the forward motion of the bullet inside the
barrel as a result of gas expansion.
•Translation – the straight motion of the bullet
where there is no rotation. It includes the bouncing
of bullet after hitting a hard object.
•Rotary – the spinning motion of the bullet as a
result of the riflings.
8. INTERIOR/INTERNAL
BALLISTICS
•The branch of ballistics which is
concerned with the properties of the
projectile or bullet while still inside the
barrel of the gun and this extends
from the breech to the muzzle.
9. THIS INVOLVES THE FOLLOWING:
(FICE-PERVE)
a. Firing pin hitting the primer
b. Ignition of the priming mixture
c. Combustion of the gunpowder
d. Expansion of the heated gas
e. Pressure developed
f. Energy generated
g. Recoil of the gun
h.Velocity of the bullet inside barrel
i. Engraving of the cylindrical surface of the bullet
11. THIS INVOLVES THE FOLLOWING:
Muzzle Blast – the sudden noise or sound created at muzzle point of the gun
by reason of the sudden escape of the expanding gas as it comes in contact
with the air in the surrounding atmosphere.
Muzzle Energy - the energy generated at muzzle point
Range – the straight distance between muzzle and target.
• Effective range – the distance within which the shooter has control of his shots, meaning he
can place his shots at a desired spot
• Maximum range – the farthest distance that a bullet can be propelled from the firearm.
12. THIS INVOLVES THE FOLLOWING:
• Trajectory – the actual curved path of the bullet during its flight
from the muzzle of the gun.
• Velocity - rate of speed of the bullet per unit of time.
• Air resistance – the power or capacity of the bullet to resist air
during its flight from the muzzle of the gun.
• Pull of gravity – that is when the bullet plunge or dive itself after
attaining its effective range.
• Penetration – the depth to which the bullet has entered its target
or object hit.
13. TERMINAL BALLISTICS
This branch of ballistics is concerned with the effects of the impact of the
projectile on the target, and this involves the following: (PAVE)
• Terminal Penetration – that depth of bullet penetration on the target or
object hit.
• Terminal Accuracy – that size of the bullet group on the target.
• Terminal Velocity – velocity of the projectile when it strikes the
target.
• Terminal Energy – that energy of the projectile when it strikes the
target. It is otherwise referred as the striking force or energy.
14. FORENSIC BALLISTICS
Technically, it is the science of firearms identification
which scientifically examines ballistics exhibits such
as: (BSFA)
1. Fired Bullets;
2. Fired Shells;
3. Firearms; and
4. Allied matters, used in crime.
15. FORENSIC BALLISTICS
It is defined as the study of the motion
of the projectile as applied to law or
simply the science of firearm
identification by means of the
ammunition fired through them.
17. FIREARM
A firearm is a mechanical
device that uses pressure from
a burning powder to force a
projectile through and out of a
metal tube.
18. FIREARM
It is an instrument used for the
propulsion of projectile by means
of the expansive force gases
coming from burning gunpowder.
19. FIREARM
Legally speaking, “Firearms” or “Arms” are herein used includes
rifles, muskets, carbines, shotguns, revolvers, pistols and all other
deadly weapons from which a bullet, ball, shot, shell or other missile
may discharge off by means of gunpowder or other explosives. The
term also includes air rifles except such as being of small caliber
and limited range used as toys. The barrel of any firearm shall be
considered a complete firearm for all purposes hereof (Sec. 877,
Revised Administrative Code see also Sec. 290 National Internal
Revenue Code).
21. Classification of Firearms
Two General Classification of Firearms
(According to Interior Barrel Construction)
1.Smooth Bore Firearms = Firearms that
have no rifling (lands and grooves) inside
their gun barrel.
Examples: Shotguns and Musket
2. Rifled Bore Firearms = Firearms that have
have rifling inside their gun barrel.
Examples: Pistols, Revolvers, and other
modern weapons.
22. Main Types of Firearms
(According to the Caliber of the projectile
propelled)
1. Artillery = Refers to those type of firearms that
propels projectile with more than one inch
diameter.
Examples: Cannons, Mortars and Bazookas:
2. Small Arms = Are firearms that propels projectile
with less than one inch diameter and it can be
handled, moved and operated by one man.
Examples: Machine gun, shoulder arms and
handguns.
23. Machine guns
Machine gun is a type of firearm that is
primarily designed for military use. Even in
investigation of shooting cases done in the city,
it is not usual or common to encounter this
type of firearm having been used. It can be
grouped in three general types:
Sub Machine Gun
Is a light, portable form of machine gun,
utilizing a pistol size ammunition, having a
shoulder stock that may or may not be folded
and designed to be fired with both hands.
24. Shoulder Arms
Are those types of firearm that were
normally fired from the shoulder.
Rifles= A shoulder weapon designed to
to fire a projectile with more accuracy
through a long rifled bore barrel, usually
more than 22 inches.
Carbine = A short barrel rifle, with its
barrel rifle, measuring not longer than 22
inches. It fires a single projectile though a
rifle-bore either semi-automatic or fully
automatic, for every press of the trigger.
25. Muskets = is an ancient
smoothbore and muzzle loading
military shoulder arms designed to fire
a shots or a single round lead ball.
Shotgun = A smooth bore and a
breech loading shoulder arms designed
to fire a number of lead pellets or a
shots in one charge (FBA Manual)
26. The barrel construction of shotgun may
also be found in different bore construction.
A. cylinder bore type = which the bore size
is the same throughout the barrel
B. choke bored gun = designed with a
diminishing or reducing bore diameter type
towards the muzzle. This type is designed to
cause an effect to the travel of the shots. It
makes the shots travel longer before it spreads.
C. “paradox gun”.= still in a very rear
occasions another type of shotgun can be
observed to be having rifling only a few inch
from its muzzle points.
27. Handguns = those type of firearms
that are designed or intended to be fired
using one hand.
Ex. Pistols and Revolvers
Pistol ═ refers to a handgun
having one chamber integral with the barrel
or it is a magazine fed type of handgun
designed to fire a single projectile through a
rifled bore for every press of the trigger.
28. Revolver ═ is a type of firearm designed
to position cartridge into position for firing
with the aid of a rotating cylinder serving as its
chamber. There are two types of revolvers
according to its mechanical firing action.
1. Single action, a type of revolver that needs
manual cocking of the hammer before
squeezing the trigger
2. Double action, a type of revolver that does
not need manual cocking. Just press the
trigger and it both cocked and released the
hammer causing a much faster firing.
29. Types of Firearms (According of Mechanical
Construction)
1. Single shot firearms = types of firearms
designed to fire only one shot every loading.
Examples: Single shot pistols,
Revolvers and shotguns.
2. Repeating Arms = A type of firearms designed
to fire several loads (shot) in one loading.
Examples: Automatic pistols revolvers
rifles and shotguns.
30. 3. Automatic F/A = type of firearms that
constitutes a continuous firing in a single
press of the trigger and while the trigger is
press.
Examples: Machine guns and rifles
4. Slide Action type = types of firearms in
which loading take place by back and forth
manipulation of the under/over forearms of
the gun.
Examples: Shotgun and pistols
31. 5. Bolt Action Type = Type of firearms in
which reloading takes place by manipulating
the both back and forth.
Examples: Rifles, shotguns and
machine guns.
6. Lever type (Break type) = loading takes
place by lever action on the firearms.
Examples: Rifles and shotguns.
32. Miscellaneous Types of Gun
1. Cane gun, knife pistols, cellphone gun,
devices principally designed for other purpose
to which a gun mechanism is incorporated also
called as Freakish gun.
2. Flare gun = designed for tracing or sending
signals or locating enemy troops.
3. Freakish gun = a tool in which firearm
mechanism is attached to prevent easy
identification.
4. Gas gun = generally referring to all gun
designed from firing tear gas.
33. 5. Harpoon guns = refers to a barbed spear
in hunting large fish.
6. Liberator = U.S. government made
smooth bore gun used in Europe during war
designed to fire an automatic colt pistol
cartridge caliber .45.
7. Multi –Barreled gun = refers to all types
of gun containing a number of barrels.
8. Paradox gun = a type of gun which
contains lands and grooves a few inch from
the muzzle point.
34. 9. Tools = are those devices which
resembles a gun designed but are
generally used for construction of
furniture.
10. Traps = refers to gun used for
trapping animals that are fired to
woods.
11. Zip Gun = refers to all type of
home made gun.
35. Legal Definition
Ammunition refers to loaded shell
for rifles, muskets, carbine, shotgun,
revolvers and pistols from which a ball,
shot shell or other missiles maybe fired
by means of gun powder or other
explosive. The term also includes
ammunition for air rifles as mentioned
elsewhere in the code. (Chapter VII,
Sec.290 of NIRC as well as Sec 877 RAC)
36. Technical Definition
Ammunition refers to a
group of cartridge or to a single
cartridge.
Cartridge is a complete
unfired unit consisting of bullet
(ball), primer (cap), cartridge
case (shell) and gunpowder
(propellant).
37. Origin
The word cartridge was derived
from the Latin word “Charta” meaning –
a “paper” and also from the French
word “Cartouche” meaning – a rolled
paper. This only indicates that the first
type of cartridge was made up of a
rolled paper. It was about the turn of
the 16th century that the term
“cartridge” comes to use.
38. General types of Ammunition
a. Dummy ( used as a model)
b. Drill Ammunition (without gun
powder)
c. Black Ammunition (without
bullet)
d. Live Ammunition
39. Classification of Cartridge According to the
Location of the Primer
a. Pin-Fire = is a type of cartridge in which the
ignition cap (primer) is concealed inside the
cartridge case and has a pin resting upon it.
b. Rim fire = is a type of cartridge in which the
priming mixture is located at the hallow rim of the
case.
c. Center fire = t refers to a cartridge in which
primer cup (ignition cap) is centrally placed in the
base of the cartridge case and the priming mixture
is exploded by the impact of the firing pin and with
the support of the anvil.
40. Classification of Cartridge According to Rim
Diameter
a. Rimmed Case type.
b. Semi-Rimmed type
d. Rimless type
d. Rebated type = refers to the
cartridge with rimless pattern, but which has
a rim diameter smaller than the body of the
case
e. Belted type = a cartridge with a
prominent raise belt around its body just in
front of the extraction groove.
41. Classification of Cartridge According Caliber
Calibers in cartridges in inches and their
approximate equivalent in mm and use:
Inches MM.
Cal. .22 about 5.59 mm- used in revolver,
pistol and rifles
Cal. .25 about 6.35 mm- used in pistols
and rifles.
Cal. .30 about 7.63 mm- (mauser) – for
carbines and other rifles
Cal. .30 about 7.63 mm (luger)
42. Cal. .32 about 7.65 mm for automatic
pistols and revolvers
Cal. .380 about 9 mm- used for pistols
Cal. .357 used in magnum .357
revolvers
Cal. .45 about 11 mm – used in
automatic pistols
Cal. .50 used in .50 cal. Machine gun
43. Shotgun Cartridge
It refers to a complete unit of unfired
cartridge consisting of the pellets, primer,
case, wads and gunpowder .
The unit of measurement used in
shotgun is expressed in Gauge. This is
determined by the number of solid lead
balls of pure lead, each with diameter of the
barrel that can be prepared from one pound
of lead. At present the 10-gauge shotgun is
considered with the biggest diameter while
the .410 as the smallest one.
44. Gauge Inch
10 .775 inch
12 .729 inch
16 .670 inch
20 .615 inch
28 .550 inch
.410 .410 inch
45. Types of Shots
1. Soft or Drop Shots = made by pure or
nearly pure lead, to which a small amount of
arsenic has been added to make it take on the
form of a spherical drop as it falls down the shot
tower. This type is easy to deformed or flattened,
loose their velocity quicker, low penetrating power
and string out more.
2. Chilled or Hard Shot = is a type of shot
with a small amount of antimony mixed with lead
to increase hardness. It does no deform easily,
better patterns, less string and more uniform
velocity and penetration.
46. 3. Coated or Plated Shot = also
called as “lubaloy” shot. A chilled shot
coated with thin copper through
electroplating design for greater
strength and elasticity, great resistance
to deformation and leading and better
pattern.
Buck Shot = a large size lead shot
for used in shotgun
47. Bullets
The word “Bullet” was derived from
French word “Boullette” which means a small
ball. This term is generally used when we are
referring to projectile fired from any small
arms, which has a variety of form, especially
during the earlier history. In a more technical
sense, bullet refers to a metallic or non-
metallic cylindrical ball propelled from a
firearm it is sometimes called as shots or
slugs.
48. Bullets have various types depending upon
their specific nature and purpose. In general bullet
can be classified as either Lead or Jacketed.
General Types of Bullets
1. Lead Type – is a type of a bullet that is basically
composed of lead metal. Its used was due to its
density; having a good weight is a small size
and easy for casting.
2. Jacketed Type – Is a type of bullet consisting of
the regular lead core, coated with a copper
alloy in order to prevent lead fouling of the
barrel and is generally used in pistols and other
high power guns.
49. Types of Bullets According to their Maximum
Effect to their targets
1. Ball Type – Is a type of bullet, which is
intended for anti-personnel and general use.
2. Armor piercing – is a type of military
bullet designed to penetrate light steel
armor. Its mechanical construction makes it
capable of penetrating through some light
vehicles.
50. 3. Explosive Bullet - Is a small bullet
containing a charge of explosive, which will
detonate on impact.
4. Incendiary Bullet –Type of military bullet
used to cause fire in a target, generally
designed to use by aircraft armament in
order for the fuel tanks to ignite.
5. Tracer Bullet – a type of military bullet
capable of leaving visible marks or traces
while in flight giving the gunner the chance
to observe the strike of the shot or make
adjustments in the event of a miss
51. Cartridge Case
Cartridge Case is the metallic
or non-metallic tabular container
usually of brass (70% copper and
30% zinc) designed to unite the
bullet, primer and the gunpowder
into one unit. It is also known as
shell or casing.
52. Functions of the Cartridge Case
1. It locates the bullet properly relative
to the bore of the firearm.
2. It is used to carry the means of
ignition.
3. It provides gas seals at the breech
against an unwanted escape of propellant
gas upon firing.
4. Serves as waterproof container for
the propellant or powder charge.
5. Acts as the insulator between the
propellant and the hot walls of the chamber
in a rapid firing of firearms.
53. Parts of the Cartridge Case
1. Base= the bottom portion of the
cartridge case which contains the head
stamp marking on the base of the shell
containing the caliber, manufacturer and in
some cases including the date, trade name,
and batch number.
2. Rim= is the part of the cartridge
designed to limit the forward movement of
the cartridge to chamber.
3. Extracting grooves= is the circular
groove near the rim of the shell designed for
automatic withdrawal of the case from the
chamber.
54. Parts of the Cartridge Case
4. Primer Pocket= is that part of the shell
which provides the means for the primer to be
put in the central position. Its function is
extended to: (a) hold the primer in place; (b) to
provide means to prevent the escape of gas; (c)
to provide solid support for primer anvil.
5. Body= is the cylindrical part of the shell
which house the gunpowder.
6. Shoulder= that part of the cartridge case
which support the neck of the cartridge which
is evident in a bottleneck type.
55. Parts of the Cartridge Case
7. Cannelure= is the cylindrical groove in the
outer surface of the cartridge case designed to
secure the shell to the chamber as well as
prevent bullet from being push down to the
powder charge. In some instance it is even
being utilized for identification.
8. Neck= is that part of the shell which is
actually occupied by the bullet. This is obvious
in a bottleneck type of shell but not with the
straight type.
56. Parts of the Cartridge Case
9. Crimp= is the cylindrical groove on the
mouth of the shell designed for two
purposes: One (1) is to hold the bullet and
prevent it from being pull out from the shell
and Two (2) to offers resistance to the bullet
out of the neck to ensure burning of the gun
powder.
10. Vent or Flash hole= is the hole at the
bottom of the primer pocket as the passage
way for the priming mixture to impart an
ignition to the propellant charge.
57. Primer
Primer (also called CAP) is the ignition
system of the cartridge used in a center fire
type, containing a highly sensitive chemical
compound that would easily ignite or bursts
into flame when struck by the firing pin. It
may either be Berdan or Boxer type. It is also
known as the percussion cup.
58. The Berdan is a type of primer construction,
which was designed in 1860s by Colonel Hiram S.
Berdan of the U.S Army Ordinance Department.
In a cartridge designed for a Berdan primer
the anvil is built into the primer pocket of the case,
rather than the primer. These cases cannot be de-
capped and reloaded by standard reloading tools.
Its anvil forms part of the cartridge case and
a number of flasholes to serve as the passage of
ignition usually two (2).
59. The Boxer on the other hand, was
developed by Col. Edward M. Boxer of the Royal
Laboratory at Woolwich Arsenal in the year
1866
In a Boxer primer, the anvil is a separate
stirrup piece that sits inverted in the primer cup
providing sufficient resistance to the impact of
the firing pin.
The primer pocket in the case head has a
single flash-hole in its center. This positioning
makes little or no difference to the
performance of the round, but it makes fired
primers vastly easier to remove for re-loading
60. Parts of the Primer
1. Primer Cup
2. Priming mixture
3. Anvil
4. Disc or thin paper or foil
61. Types of Priming Mixture Compound
1. Corrosives – one consisting potassium
chlorate added with antimony sulfide and
mercury fulminate, which when ignite
produces moisture causing formation of rust
in the bore of the firearm.
2. Non-corrosives – one which is
designed for less chances of rusting by
replacing the potassium chlorate with
barium nitrate.
62. Gun Powder
Gunpowder (also called as propellant
or Power Charge) is that mixture of
chemicals of various compositions designed
to propel the projectile by means of its
expansive force of gas when burned.
Two of the most popular individual
whose name is always attached to
gunpowder discovery were Roger Bacon and
Berthold Schwartz.
63. The Black Powder
Black powder, the oldest known
explosive, was initially made from saltpeter
(75%), charcoal (15%) and sulfur (10%).
It is a propellant which when fired,
produces large volumes of grayish smoke and
considerable amount of residue left in the
barrel of the gun. Black powder have three
qualities which are typical in all explosives; 1)
when ignited, it will burn rapidly by itself,
without the aid of the air outside, 2) in burning,
it gives off a large amount of gas and, 3) A
considerable amount of heat is produced.
64. The smokeless powder is a propellant
which when fired, does not give off huge
cloud of white smoke like black powder. It is
the most powerful propellants.
Captain E. Schultze of the Prussian
Army, made the 1st successful used of
smokeless powder in shotgun in the year
1864. The basic ingredient used for
smokeless powder is a nitrocellulose that
was first produced by adding a nitric acid to
cellulose fiber.
65. Types of Characteristics in Firearms
A. Class Characteristics = are those
properties or attributes of a firearms which can
be determined even before the manufacture of
the gun. This is true for such characteristics are
considered to be a manufacture’s designs or
specifications and security.
B. Individual Characteristics = are
for those characteristics which are being
determined only after the firearm was already
been manufactured. They are the product of
machine imperfections and some later due to
the used of the firearms.
66. Class Characteristics of Firearms
1. Bore diameter (caliber or gauge)
2. Number of lands and grooves. It may run
from 3 to 8, but the most in the modern
firearm are five and six.
Lands = are the elevated portion of the
bore of the firearm.
Grooves = are the depressed portion of
the bore between the lands.
3. Width of the lands = are the remainders
of the circumference after subtracting all the
grooves width.
67. 4. Width of the Grooves
5. Direction of Twist
6. Pitch of Rifling = it is the measure of the
twisting of the lands and grooves. It refers to
the measure of the distance advance by the
rifling in order to make a complete turn
inside the barrel.
7. Depth of the Grooves are usually few
thousandths of an inch deep, which equal to
the height of the lands.
68. Types of Rifling
1. Steyer Type= is the type of rifling having
four (4) lands and grooves, right twist and
the width of the lands and grooves are
equal. (4 RG=L)
2. Carbine Type = rifling having (4) lands and
and grooves, right twist, the width of the
grooves is two (2) times the width of the
lands (4RG2X).
3. Smith and Wesson = rifling having (5)
lands and grooves, right hand twist , the
width of the land and grooves are equal.
(5RG=L)
69. 4. Colt = type of rifling having six (6) lands and
grooves, left twist, the width of the grooves is twice
(2) the width of the lands. (6LG2X)
5. Browning = type of rifling having (6) lands and
grooves, right hand twist, the width of the grooves
is twice the width of the lands. (6RG2X)
6. Webley = Rifling having seven (7) lands and
grooves, right hand twist, the width of the groove
is three time larger than the boarder of the lands.
(7RG3X)
7. Winchester = Rifling having six (6) lands and
grooves, right hand twist, the width of the grooves
is three time larger the width of the lands. (6RG3X)
70. Individual Characteristics in Firearms
Individual Characteristics in firearms are
usually determined by the test firing which
will give us both the test bullet and the test
shell that will show the individuality of its
property based on the left marks on every
bullet and shell fired from it. Such marks are
so minute that the use of the lens with high
magnification is necessary to discover
individuality.
71. Marks found of Fired Bullets
1. Land Marks = marks left on a fired
bullet caused by its contact to the elevated
portion (lands) of the bore of the firearm. It
appears as slight depressions or scratches
the cylindrical surface of the fired bullet.
2. Groove Marks = marks found on a fired
bullet caused by the grooves of the barrel
which is the same number as that of the
landmarks.
72. 3. Skid Marks = Marks that are generally found on
fired bullet from a revolver. It is more or less
located at the anterior portion of the fired bullet
due to its forward movement from the chamber to
the barrel of the gun before it initially rotates.
4. Stripping Marks = marks found on those bullet
fired from a “loose-fit” barrel wherein the rifling
are already been badly worn-out.
Worn-out in the rifling of the firearms can be cause
by either chemical reaction brought about by rust
(corrosion) or through excessive use (erosion)
73. 5. Shaving Marks = marks commonly
found on bullet fired from a revolver
cause by its forward movement to the
barrel that is poorly aligned to the
cylinder.
6. Slippage Marks = marks found on
fired bullets passing through either on
oily or oversize barrel.
74. Marks found on Fired Shells
1. Firing Pin Mark = found at the base portion
of the cartridge case more specifically near
center of the primer cup in a center fire
cartridge or at the rim cavity of a rim-fire
cartridge.
2. Breech Face Mark = found at the base
portion of the shell cause by backward
movement to the breech face of the block of
the firearm.
3. Extractor Mark = found at the extracting
groove of the fired cartridge case cause by
its withdrawal from the chamber.
75. 4. Ejector mark = found on cartridge case
fired from an automatic firearms. It is
located near the rim of the case cause by the
throwing of shell from the firearm to the
area of shooting.
5. Shearing Mark = sometimes called
“Secondary Firing Pin mark” found in the
primer near the firing pin mark.
6. Magazine Lip Mark = found at the two
sides of the rim cause by the magazine lips
during the loading of the cartridge into the
magazine for firing.
76. 7. Chamber Mark = found around the body
of the fired cartridge case cause by the
irregularities of nips inside the walls of the
chamber.
In fired cartridge case either of the
Firing pin mark and the Breech face marks
can be used as basis for identification, in
the absence or none use of these two, both
the ejector and extractor marks can be
utilized as secondary choice.
77. Problems in Forensic Ballistics
1. Given a fired bullet to determine the
caliber, type; make of firearm from which
it was fired.
2. Given a fired shell to determine the
caliber, type, and make of firearm from
which it was fired.
78. Problems in Forensic Ballistics
3. Given a fired bullet and a suspected
firearm, to determine whether or not
the fired bullet was fired from the
suspected firearm.
4. Given a fired shell and a suspected
firearm, to determine whether or not
the fired bullet was fired from the
suspected firearm.
79. Problems in Forensic Ballistics
5. Given two or more fired bullets, to
determine whether or not they were
fired from one and the same firearm.
6. Given two or more fired shell/cartridge
case, to determine whether or not they
were fired from one and the same
firearm.
7. Given a suspected firearm, to determine
whether it is serviceable or not.
80. Scientific Instrument Used in
Firearms Identification
1. Analytical or Torsion Balance
2. Bullet Comparison
Microscope
3. Bullet Recovery box
81. Scientific Instrument Used in Firearms
Identification
4. Chronograph used for determining
bullet velocity
5. Caliper used for measuring the
opposites sides and diameter of the
bore
6. CP-6 Comparison Projector
82. Scientific Instrument Used in Firearms
Identification
7. Helixometer is a tubular instrument in which
an electric light and a prism and lens system
enable visual examination of a small-arms
bore.
8. Micrometer is almost look like a caliper used
for precise measurement of small distances.
9. Onoscope is inserted a few inches into to the
barrel for proper identification.
83. Scientific Instrument Used in Firearms
Identification
10. Shadowgraph is used to produced
image by casting a shadow on a screen.
11. Stereoscopic Microscope is used for
viewing relatively large and solid surfaces
or specimens.
12. Taper Gauge re used to inspect tapered
bearing seats in production facilities.
This is necessary to ensure a good
match.