Forensic Ballistics
BALLISTITE
- Developed by Alfred Nobel on the year 1887 - Nobel's gun powder is composed of 40% nitroglycerine and 60% nitrocellulose, a powder easier to handle and more powerful than Poudre B.
Shot pattern
- It is the spread of shot pellets after they hit a non-moving target
Gauge
- The term used to designate bore diameter of a shotgun, gauge is the number of lead balls with diameters equal to the diameter of the bore that, when combined weigh one pound.
CARTRIDGE CASE
- The tubular metallic or non-metallic container that holds together the bullet, gunpowder and primer.
Gunshot Wound (GSW)
- an open wound produced by the penetration of bullet slug within the tissues of the body.
RIFLING
- consist of a number of helical grooves cut in the interior surface of the bore
Shot Spread
- is determined by a constriction or narrowing at the muzzle called "a choke.
Choke
- it is the degree of narrowing at the muzzle end of the shotgun barrel
POUDRE B
- smokeless powder Developed by Paul Vieille in France on the year 1186 - This was made from gelatinized nitrocellulose mixed with ether and alcohol, it was passed through rollers to form thin sheets, which were cut with a guillotine to flakes of the desired size.
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3 Points of Basic Positive Identification The markings must be: (CSP) Consistent Significant; and Prominent Note: ______ or more striations accepted by the court.
Motion
? In relation to ballistics, it refers to the movement or mobility of the projectille from one point to another.
Projectile
? It is the metallic or non-metallic objects propelled from a fiream.
yaw
? It is the unstable motion of the projectile.
gyroscopic acton
? It is the stillness of the rotating motion and attained its highest momentum for stability in flight and penetrating power
BULLET
A metallic or non-metallic cylindrical projectile propelled from a firearm by means of the expansive force of gasses coming from burning gunpowder.
PRIMER
A small metallic ignition cup at the center of the base, When the striker hits the base of the cartridge , a distinctive mark is placed by the gun on this.
1)Pistols 2)Revolvers 3)Break-top type (lever action) 4)Ejection-rod type 5)swing out type 6)Single-action 7)Double-action
ACCORDING TO GENERAL USE AND DESIGN (H SMS) Handguns Shoulder firearms Machine guns Sub machine gun HANDGUNS (PR) - __1__ - small portable fireams that can be held, aimed, and fired with one hand. a. Single-shot pistols b. Semi-automatic pistol -__2__ - have rotating cylinder containing chambers designed to position a cartridge ready for firing a. According to mechanical construction (BES) -__3__ loading is done by breaking the top to expose the chamber. -__4__ - a rod is ejected in order to expose the chamber. - __5__ - loading can be done by swinging out the cylinder. b. According to mechanical firing action (SD) - __6__, it needs manual cocking of the hammer - __7__, squeezing the trigger automatically cocks the hammer SHOULDER WEAPONS - Muskets - Rifles - Carbines - Shotguns MACHINE GUN -Gatling gun -Maxim gun
TRIGGER
BASIC PARTS OF FIREARM AND FUNCTIONS. - Actuates the parts necessary to fire the weapon.
BREECH-BLOCK
BASIC PARTS OF FIREARM AND FUNCTIONS. - Also known as the bolt, it is the steel block that closed the breech against the force of the charge during firing; the face of this block which comes in contact with the base of the cartridge is the breech-face
STRIKER
BASIC PARTS OF FIREARM AND FUNCTIONS. - Alternative term for the firing pin when that firing is axially mounted and spring propelled inside the bolt
YOKE
BASIC PARTS OF FIREARM AND FUNCTIONS. - Connecting pivot between the frame and cylinder.
TRIGGER GUARD
BASIC PARTS OF FIREARM AND FUNCTIONS. - Guards the trigger from unnecessary action to avoid accidental firing.
MAIN SPRING
BASIC PARTS OF FIREARM AND FUNCTIONS. - Provides energy to the hammer to activate firing mechanism.
EXTRACTOR
BASIC PARTS OF FIREARM AND FUNCTIONS. - Pulls the empty shells from the cylinder simultaneously.
HAMMER
BASIC PARTS OF FIREARM AND FUNCTIONS. - Strikes the blow that initiates or ignites primer
SAFETY
BASIC PARTS OF FIREARM AND FUNCTIONS. - The gun mechanism that prevents the firearm from firing; it may be a button, moveable pin, lever, thumb hammer or sliding plate
ACTION
BASIC PARTS OF FIREARM AND FUNCTIONS. - The heart of the fiream- the moving parts that load, fire, and eject the shells or cartridges.
BARREL
BASIC PARTS OF FIREARM AND FUNCTIONS. - initiates the path of the bullet.
EJECTOR
BASIC PARTS OF FIREARM AND FUNCTIONS. - it pushes the spent shell away from the firearm.
BOLT
BASIC PARTS OF FIREARM AND FUNCTIONS. - Disengage center prim to allow opening of cylinder and blocks hammer.
FRAME
BASIC PARTS OF FIREARM AND FUNCTIONS. - Houses the internal parts
STOCK
BASIC PARTS OF FIREARM AND FUNCTIONS. - Serves as the handle of the firearm. It can be composed of one or two pieces and is usually made of wood or a synthetic material.
CHAMBER
BASIC PARTS OF FIREARM AND FUNCTIONS. - The part of the bore into which a cartridge is placed; the enlarged space at the breech of the barrel where the cartridge is fed
BREECH
BASIC PARTS OF FIREARM AND FUNCTIONS.. - The part of the barrel at the opposite end of the muzzle
INTERIOR/INTERNAL BALLISTICS
BRANCHES OF 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
EXTERIOR/EXTERNAL BALLISTICS
BRANCHES OF BALLISTICS. This branch of ballistics is concerned with the movements and attributes of the bullet after it has left the muzzle of the gun, which involves the following:
TERMINAL BALLISTICS
BRANCHES OF BALLISTICS. This branch of ballistics is concerned with the effects of the impact of the projectile on the target
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Bullets are jacketed with various metallic materials or alloys because of the following purposes: (PIDED) - To Prevent adherence of lead on the barrel's rifling (main purpose) - To keep the bullet Intact when it hits the target - To prevent Deformation while the bullet is in its path towards the target (lead bullets are deformed at very high bullet velocities)To control Expansion once the bullet hits the target -To prevent bullet Damage while inside the weapon
Rifled bore Firearms
CLASSES OF FIREARM A. According to Gun Barrel Internal Construction. - - Firearms that have rifling inside their gun barrel
Smooth-bore firearms
CLASSES OF FIREARM A. According to Gun Barrel Internal Construction. - fire arms that have no rifling (land and grooves) inside their gun barrel
Slide Action Type (Trombone)
CLASSES OF FIREARM According to Mechanical Construction. Loading takes place by back and forth manipulation of the under forearm of the gun.
Lever Type (Break Type) -
CLASSES OF FIREARM According to Mechanical Construction. Loading takes place by lever action of the Fiream.
Automatic Loading Type
CLASSES OF FIREARM According to Mechanical Construction. - After the first shot is fired, automatic loading or feeding of the chamber takes place.
Repeating Arms
CLASSES OF FIREARM According to Mechanical Construction. - Fire several shots in one loading
Bolt Action Type
CLASSES OF FIREARM According to Mechanical Construction. - Reloading is done by manipulation of the bolt.
Single Shot
CLASSES OF FIREARM According to Mechanical Construction. - type of firearms designed to fire only one shot for e very loading.
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CLASSES OF FIREARM According to USE - Military Firearms - Pocket and Home Defense fire arms
Drill ammo
CLASSIFICATION OF AMMUNITION BASED ON GENERAL USE. - completely inert and without an explosive propellant. It is used in military training to practice loading and manipulation of firearms.
Blank ammo
CLASSIFICATION OF AMMUNITION BASED ON GENERAL USE. - a cartridge without a bullet. lt may contain gunpowder and priming mixture thus designed to produce gunshot to indicate firing. This is used for theatrical perfomance and military training.
Dummy
CLASSIFICATION OF AMMUNITION BASED ON GENERAL USE. - carefully made replica of a cartridge, usually made of steel and discreetly dimensioned to be used by weapons instructors, inspectors and repairmen when checking if weapons are functional.
Live ammo
CLASSIFICATION OF AMMUNITION BASED ON GENERAL USE. - the real ammunition since it is composed of a complete unit of unfired cartridge.
Pin-fire cartidge
CLASSIFICATION OF AMMUNITION. ACCORDING TO LOCATION OF PRIMER.. - primer cup is concealed inside the cartridge case. A pin is resting upon the primer. The pin protrudes at the side of the cartridge. The gun chamber has a notch for the pin to stand when loaded in the squeezing the trigger.
Center-fire cartridge.
CLASSIFICATION OF AMMUNITION. ACCORDING TO LOCATION OF PRIMER.. - cartridge mostly used today. The primer cup is centrally placed at the base of the cartridge. The priming mixture is exploded by the impact of the firing on the primer cup which is supported by the anvil.
Rim-fire cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO LOCATION OF PRIMER.. - the priming mixture is located at the hollow portion of the rim of the cartridge case. It can be fired if the firing pin strikes the bottom of the cartridge at the rim area. This cartridge type can be identified easily by the smooth base of the. At present, rim-fire cartridge is exclusively used by .22 cal. revolvers.
High-power cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO POWER. - a cartridge that fires a projectile with muzzle velocity between 1,925 and 2,500 fps
High-intensity cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO POWER. - the projectile fired from this cartridge has muzzle velocity of more than 2,500 fps
Low-power cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO POWER. - a cartridge that fires a projectile with a muzzle velocity of less than 1,850 fps
Belted cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO RIM. - The type of cartridge originally designed for machineguns. The extractor's groove is strengthened with another layer of metal to prevent the machine gun's extractor from damaging the cartridge case.
Semi-rimmed
CLASSIFICATION OF AMMUNITION. ACCORDING TO RIM. - the rim is slightly wider than the case. - Belted cartridge - The type of cartridge originally designed for machineguns. The extractor's groove is strengthened with another layer of metal to prevent the machine gun's extractor from damaging the cartridge case.
Rebated cartridges
CLASSIFICATION OF AMMUNITION. ACCORDING TO RIM. - A rare type of cartridges because the rim has smaller diameter than the cartridge case.
Rimless cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO RIM. - The type of cartridge which is true to pistol and rifle ammunition. The cartridge case and the rim have equal diameter.
Rimmed cartridge
CLASSIFICATION OF AMMUNITION. ACCORDING TO RIM. - the design of catridges for revolvers, shotguns, and some rifles. The cartridge has a rimmed base - that is the rim diameter is obviously wider than the case diameter, and it has no extracting groove.
Rifle ammo
CLASSIFICATION OF AMMUNITION. ACCORDING TO THE TYPE OF FIREARMS WHERE THEY ARE LOADED. - for hunting rifles, sniping rifles, assault rifles, machine guns, and some submachine guns, this type of cartridge has a bottle-neck Shape. It has longer case for large powder capacity and increased power.
Pistol ammo
CLASSIFICATION OF AMMUNITION. ACCORDING TO THE TYPE OF FIREARMS WHERE THEY ARE LOADED. - for pistols, carbines and most submachine guns, this type of ammunition has extractor's groove instead of a rimmed base.
Revolver ammo
CLASSIFICATION OF AMMUNITION. ACCORDING TO THE TYPE OF FIREARMS WHERE THEY ARE LOADED. - for revolvers, this type of ammunition has a rimmed base and a straight case which allows the bullet to be rammed the chamber of the revolving cylinder.
Shot shell
CLASSIFICATION OF AMMUNITION. ACCORDING TO THE TYPE OF FIREARMS WHERE THEY ARE LOADED. - for shotguns. The case of this ammunition is generally made of plastic with a metallic base. It usually contains several pellets, although special types of shotgun ammo may be loaded with single slugs.
Case-less ammo
CLASSIFICATION OF AMMUNITION. ACCORDING TO THE TYPE OF FIREARMS WHERE THEY ARE LOADED. - a special type of ammo. The gunpowder serves as casing of the bullet.The entire cartridge is coated with varnish or similar material to protect it from moisture and moderate shocks. -can be used in hand guns and rifles.
1)Lead bullets 2)Jacketed bullets
CLASSIFICATION OF BULLETS General groups of bullets according to composition(LG) - __1__ - These are made of pure lead or alloyed with tin and antimony. Lead alloy is slightly harder than pure lead. Traditionally, lead bullets are for revolvers and caliber.22 rim-fire cartridges. Pure lead bullets are not satisfactory for use when high velocities are involved. - __2__ - Metal-jacketed bullets are the types of bullets with lead core covered by soft brass or copper-plated soft steel jacket. The core is Composed of lead-antimony alloy for hunting and for military anti-personnel cartridges.
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CLASSIFICATION OF LEAD BULLETS ACCORDING TO SHAPE -Round nose -Wad cutter - Semi wad-cutter - Hollow point - Boat Tailed
shell and casing
Cartridge case for small arms ammunition is also called ___ and ____.
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Cartridges and cartridge cases on the other hand are examined for class similarities that could be in the form of: (BEEF) 1. Breech mark 2.Extractor mark 3. Ejector mark 4. Firing pin impression
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Class characteristics of firearms that can be determined in bullets fired from them are as follows: (CaRN-W-DDD) - Caliber of the firearm - Rifling pattern contained in the barrel of the firearm - Number of lands and grooves - Width of lands and grooves - Depth of grooves - Degree of rifling twist - Direction of rifling twist
1)Muzzle Blast 2)Muzzle Energy 3)Range 4)Effective range 5)Maximum range 6)Trajectory 7)Velocty 8)Air resistance 9)Pull of gravity 10)Penetration
EXTERIOR/EXTERNAL BALLISTICS This branch of ballistics is concerned with the movements and attributes of the bullet after it has left the muzzle of the gun, which involves the following: (BERT-VAPP) a. __1__- 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 b. __2__ - the energy generated at muzzle point c. __3__- the straight distance between muzzle and target. -__4__ the distance within which the shooter has control of his shots, meaning he can place his shots at a desired spot -__5__- the farthest distance that a bullet can be propelled from the fiream. d. __6__- the actual curved path of the bullet during its flight from the muzzle of the gun. e. __7__- rate of speed of the bullet per unit of time. f. __8__ the power or capacity of the bulet to resist air during its flight from the muzzle of the gun. g. __9__- that is when the bullet plunge or dive itself after attaining its effective range. h.__10__- the depth to which the bullet has entered its target or object hit.
1)Identification 2)Inconclusive 3)Elimination 4)No Conclusion/Unsuitable
Examination Results in Firearms Identification. 1. __1__- signifies a match between two specimens. "Agreement of a combination of individual characteristics and all discernible classcharacteristics. 2. __2__- represents a no match between the examined items of evidence 3. __3__- elimination is a significant disagreement of discernible class characteristics and/or individual characteristics. 4. __4__ - indicates that specimen submitted could neither be identified nor eliminated as having been fired by a particular weapon based on the quantity and quality of microscopic markings.
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FIREARM CHARACTERISTICS Firearms identification is mostly concerned with the examination of the characteristics left by the firearm on any ballistics related evidence, These are features/traits of the Firearms that can be transfered to the ammunitions fired through them and are used to identify them. These characteristics may come in two categories namely: -Class Characteristics -Individual characteristics
1)FIELD INVESTIGATION 2)TECHNICAL EXAMINATION 3)LEGAL PROCEEDINGS (COURT TRIALS)
FIREARMS IDENTIFICATION Firearms identification can be defined as the systematic identification of fired bullets, fired cartridge cases, or other ammunition components as having been fired from a specific firearm. Firearms ldentification involves the following: 1. __1__- refers to the work of an investigation in the field. It concerns mostly with the collection, marking, preservation, packing and transmission of fireams evidences. It includes the study of class characteristics of fireams and bullets 2. __2__ refers to the examiners who examine bullets/ or shells, whether fired from also whether or not cartridges were loaded and ejected made by the suspected fireams submitted. Reports are made by the examiners and testiy in court regarding their reports 3. __3__ - the most critical part in the field of firearm identification wherein the examiner will go to the court as expert witness regarding the ballistics report and exhibits he had prepared and examined in the laboratory.
1)Cartridge Case 2)Bullet 3)Propellant 4)Primer
FOUR MAJOR COMPONENT OF A STANDARD CARTRIDGE (CarB-ProP) 1. __1__ - it is also called shell, this is the tubular metallic container for the gunpowder. 2. __2__ g it is also called slug, this is the projectile propelled from a firearm 3. __3__ - this is the powder charge intended to be burned thus generating an energy that will launch the bullet. 4. __4__ - it is also called percussion, this is composed of the metal cup and priming mixture which is highly sensitive.
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FUNCTIONS OF CARTRIDGE CASE (HCG) - To Hold the bullet, gunpowder and primer thus assembling them as one unit; - To serve as waterproof Container for the gunpowder, and - To act as Gas seal' at the breech end of the barrel during firing.
1)Chrome molybdenum steel 2)stainless steel
GUN MANUFACTURING PROCESSES RELATED TO FIREARMS IDENTIFICATION In most cases, the process of manufacturing the gun or its components is one of the important keys in firearms identification. Imperfections on the tools or equipment used in the production of fireams will result to the characteriscs of such firearms that would be imparted on the ammunition component coming from them. MAKING THE GUN BARREL Gun barrels are made of solid steel. There are 2 classes of steel currently used in making gun barrels; Chrome molybdenum steel and stainless steel. __1__ is mostly used in hunting rifles and military firearms. On the other hand, __2__ is mostly used in barrels of target shooting fireams.
Tattooing
Gunshot Wound Characteristics. (a.k.a. peppering) caused by the embedding of unburnt and semi-burnt powder particles into the surface of the target.
Scorching
Gunshot Wound Characteristics. - caused by the flame or hot gases not by the hot projectiles as is commonly believed; also known as burning or charring.
Muzzle Pattern
Gunshot Wound Characteristics. - indicates contact wound and are often observed in suicide cases; edges are found ragged (torn in star shape) and the wound is like an exit wound.
Blackening
Gunshot Wound Characteristics. caused by the deposition of smoke particles by all types of powders at close ranges.
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INTERIOR/INTERNAL BALLISTICS The branch of ballistics which is concemed 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 This involves the following (FICE-PERVE) a. Firing pin hitting the primer b. ignition of the priming mixture c. Combustion of the gunpowde 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
1)slug 2)Boulette 3)shot shells 4)skirted
In layman's term,the bullet is called __1__. The word bullet came from the French word __2__' which roughly means little ball. As distinguished from pellets, bullets are slugs that have pointed tip or cylindical nose loaded in cartridges for rifled guns while pellets are small spherical projectiles loaded in __3__ for smooth bore weapons. Pellets, more often called shots, may also refer to __4__ projectiles used in pellet guns.
GUN POWDER
It is the chemical substance of varied compositions, sizes,shapes, and colors that function as propellant. It serves as the sources of energy to propel a projectile. Once it is burned in a confined place, it produces large volume of heated gases that expand thus generating energy capable of pushing through the gun barrel and launched it to fly towards a target.
PITCH OF RIFLING
It is the distance that the rifling advances to make one complete turn.
Ballistics
It is the science of motion of projectile and the condition governing that motion.
WOUND BALLISTICS
It is the study of the effects of projectile to human body.
1)Contact 2)Close discharge 3)Distance Discharge
Kinds of GSW Distinguished by the Proximity of the Weapon: ,•__1__- gun muzzle pressed against, or within an inch or two, of the body. •__2__ - 6 inches to 2 ft. •__3__ - over 2 ft. or 3 ft.
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LAPPING It is the process of polishing the inner surface of the gun barrel. It simply involves rubbing the bore surface using a polishing compound to remove machining marks and any tight spots in the rifling thus making the bore's surface dimensionally uniform from end to end. It is worthy to note however that no matter how many times we polish or finish the interior surface of the gun barel ,the minute imperfections cannot be removed. These microscopic imperfections cause the series of striation on the bearing surface of the bullet that passes through the barrel. These striations are the mechanical fingerprints of the gun found in fired bullets which are used as basis of firearm identification. Take note that the barrel of the gun is made of a harder metal than the bullet. When a harder metal comes in contact with a softer metal, it is always the softer metal that gets marks from the harder metal. This is the basic principle applied in explaining why do guns leave their marks on the bullet and shell that they fire.
Land marks
MARKS FOUND ON FIRED AMMUNITION COMPONENTS depressed portion found on fired bullet caused by the land.
Groove marks
MARKS FOUND ON FIRED AMMUNITION COMPONENTS - raised or elevated portion caused by the grooves.
Slippage/Stripping Marks
MARKS FOUND ON FIRED AMMUNITION COMPONENTS - these are marks found on bullets fired from a worn-out barrel, oily barrels and slightly over-sized bullets.
Shaving Marks
MARKS FOUND ON FIRED AMMUNITION COMPONENTS - most commonly found on bullets fired from a revolver due to a poor alignment of the cylinder with the bore.
Skid marks
MARKS FOUND ON FIRED AMMUNITION COMPONENTS. - this happens when the bullet enters the rifled bore from a stationary position and is forced abruptly into the rifling, its natural tendency is to go straight forward before entering the regular rifling twist. These markings are more pronounced in the revolver and caused due to worn out barels.
Firing Pin impression
MARKS FOUND ON FIRED. CARTRIDGE CASE the indentation in the primer of a centerfire cartridge case or in the rim of a rimfire cartridge case caused when it is struck by the firing pin.
Shear marks or the secondary firing pin marks
MARKS FOUND ON FIRED. CARTRIDGE CASE. found in the primer near the firing pin mark.
Firing pin drag marks
MARKS FOUND ON FIRED. CARTRIDGE CASE. it is caused by the protruding nose of the firing pin.
Ejector marks
MARKS FOUND ON FIRED. CARTRIDGE CASE. - marks produced upon a cartridge or cartridge case on the head, generally at or near the rim, from contact with the ejector.
Extractor marks
MARKS FOUND ON FIRED. CARTRIDGE CASE. - marks produced upon a cartridge or cartridge case from contact with the extractor. These are usually found on or just ahead of the rim. These are usually found on shells fired from pistols, rifles, shotguns and machineguns.
Chamber marks
MARKS FOUND ON FIRED. CARTRIDGE CASE. - marks upon a cartridge case by the chamber wall as a result of Chambering, Expanding during firing or Extraction
Breechface markings
MARKS FOUND ON FIRED. CARTRIDGE CASE. - negative impression of the breechface of the firearm found generally on the base or the head of the cartridge case after firing.
Foreign Materials
Other GSW Characteristics: - Their presence not only permits the identification of the firearms injury but they also permit a fairly reliable guess of firearm
Contusion
Other GSW Characteristics: - caused by the impact of the projectile(reddish dark to bluish black - varies somewhat with the age of the injury). It takes the form of a belt around the wound. It is of unifom in thickness.
Dirt Ring
Other GSW Characteristics: - deposited by some projectile (which carry greases on them) around the wound. Existence of this indicates the entrance side of a firearm injury.
Pink Coloration
Other GSW Characteristics:. - caused by absorbed carbon monoxide in the skin and flesh.
1)Base 2)Heel 3)Bearing surface 4)Cannelure 5)Jacket 6)Core 7)Shoulder 8)Ogive 9)Tip or Nose 10)Head-height
PARTS OF STANDARD BULLET __1__- the portion of the bulet that receives the thrust and heat from the burning gunpowder __2__- the part where the base and bearing surface meet __3__ - the cylindrical side of the bullet that comes in contact with the barel rifling __4__ - the groove around the body of a bullet to receive the case crimp; for lead bullets, this part is better known as lubricant groove __5__- a metal covering of the bullet's lewd core which could be made of copper, brass, steel, aluminum, or an alloy of these metals; it may partially or completely cover the lead Core __6__- bulk of mass in the bullet; the main component of the bullet that is usually made of lead but sometimes alloyed or replace with other metals for special purposed such as deeper penetration and tracing __7__ - the part where the parallel sides end and the ogive begins __8__ - the radius of curve between the bearing surface and the point usually stated with respect to the caliber __9__ - the most forward point of the ogive __10__- - the length of the bullet from the shoulder to the tip
Primer pocket
PARTS OF THE PRIMER. - It simply refers to the space at the center bottom of the shell where the primer cup, priming mixture and anvil occupy.
Primer cup
PARTS OF THE PRIMER. - This is the container of the priming mixture. It is composed of brass and copper or any other gilding metal.
Disc
PARTS OF THE PRIMER. - This is small piece of paper or disc of tin foil which is pressed over the priming mixture. Its dual purpose is to hold the priming mixture in place and to exclude moisture that might degrade the quality of the priming mixture.
Anvil
PARTS OF THE PRIMER. - it is a thin but rigid metal strip where the priming mixture is crushed once the firing pin strikes the primer cup.
Priming mixture
PARTS OF THE PRIMER.. - this is the chemical component of the primer.
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PRINCIPLES OF BULLET IDENTIFICATION - No two barrels are microscopically identical as the surface of their bores all possesses individual characteristics markings of their own. - When a bullet is fired from rifled barel, it becomes engraved by the rifling and this engraving will vary in its minute details with every individual bore. So it happens that the engraving on the bullets fired from one barrel will be different from another bullet fired from another barrel. - Every barrel leaves its thumb mark or fingerprint on very single bullet fired through it just as every breech face leaves its thumb mark on the base of every fired cartridges case.
EVERY GUN LEAVES CERTAIN MARKS ON THE BULLET IT FIRES
PRINCIPLES OF FIREARMS IDENTIFICATION The main forensic principle applied in firearms identification states that _________. These marks differ from those made by any other gun. This principle is used in the interpretation of all ballistic related evidence and phenomenon or ballistics exhibit with the purpose of interpreting or establishing the true facts in a shooting related incident. These ballistics related exhibits are the following: (FBC) -Firearms -Bullets -Cartridge cases On the other hand, there is countless list of ballistic related phenomenon but the most common are the following:(B-DaTH-GWS) - Bullet Damage on various mediums - Bullet Trajectories - Bullet Holes - GunShot Wounds
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PRINCIPLES OF SHELL IDENTIFICATION - The breech face and striker of every single fiream leave microscopical individualities of their own. - The firearm leaves its "fingerprints" or "thumb mark"on every cartridges case which it fires - The whole principles of identification is based on the fact that since the breech face of every weapon must be individually distinct, the cartridges cases which it fires are imprinted with this individuality. The imprints on all cartridges cases fired from thesame weapon are always the same; those on cartridges cases fired from different weapons are different.
Taper Gauge
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Use primarily for determining bore diameter of a smoothbore fiream.
Analytical or torsion balance
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Use to determine weights of bullets and pellets for possible determination of type, caliber and make from which fired.
Bullet Comparison Microscope
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. A piece of optical equipment frequently employed by firearms identification expert is the bullet comparison microscope, with camera attachment.
Shadowgraph
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. A series of microscopic lenses of different magnification determine to class use characteristics of fired bullets and shells.
Bullet Recovery Box
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Long box (12" x 12" x 96") filled with ordinary cotton and separated into sections by and board partitions.
Stereoscopic Microscope
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. No camera attachment and no photomicrograph can be taken for court tampered serial number.
Onoscope
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Small instrument sometimes used in examining the internal surface of the gun barrel indetermining the regularities inside the bore of the gun barrel. It has a tiny lamp the terminal portion and is inserted inside the bore for internal examinations.
Caliper
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Use for making measurements such as bullet diameter barrel length.
Helixometer
SCIENTIFIC EQUIPMENT GENERALLY USED IN FIREARMS IDENTIFICATION. Used in measuring "pitch of rifling". Distance traveled by the bullet in one complete rotation.
1498
SOME IMPORTANT DATES IN FIREARMS HISTORY. Rifings. The first reference to riffed barrels appeared. Although its important as an aid to accuracy was recognized by some, it was many years after before rifling was generally used.
1350
SOME IMPORTANT DATES IN FIREARMS HISTORY. Small arms- gunpowder was first used only in cannons. It was in the middle of the 14th century that portable hand firearms were introduced. These guns were ignited by a hand held hot wire or lighted match
1884
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Automatic machinegun. Hiram Maxim built the first fully automatic gun, utilizing the recoil of the piece of load and fire the next charge
1858
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Centerfire cartridge. The Morse cartridge of 1858 marked the beginning of the rapid development of the centerfire cartridge
1807
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Percussion System. The discovery of Forsyth that certain compounds detonated by a blast would be used to ignite the charge in a firearm, for the basis for all-later percussion and cartridge development.
1845
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Rimfire cartridge. In France, Flobert developed a bullet breech cap" which was in reality the first rimfire cartridge.
1885
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Smokeless powder. In France, Vielle developed the first satisfactory smokeless powder, a new propellant which not only lacked the smoke characteristic of black powder, but also more powerful.
1575
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Cartridge. Paper cartridge combining bot powder and ball were developed. This greatly speeded loading and reduced the hazards of carying looses powder.
1313
SOME IMPORTANT DATES IN FIREARMS HISTORY. - Gunpowder as a propellant. The age of gunpowder began with its first used as a propellant as a projectile. Such used has been recorded as early as .
1836
SOME IMPORTANT DATES IN FIREARMS HISTORY. Pinfire cartridge. Developed by Le Faucheux in 1836 was probably the first self-exploding cartridge to come into general used.
1835
SOME IMPORTANT DATES IN FIREARMS HISTORY. Samuel Colt patented the first practical revolvers in which the cylinder was rotated by cocking the hammer.
Oliver F. Winchester
SOME PIONEERS IN FIREARMS DEVELOPMENT. One of the earliest rifles and pistols maker
John C. Garand
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Designed and invented the Semi-automatic US rifle, caliber.30, M1
Alexander John Forsyth
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Father of the percussion ignition system
Eliphalet Remington
SOME PIONEERS IN FIREARMS DEVELOPMENT. - One of the first rifle maker
John T. Thompson
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Pioneered the making of Thompson submachine gun
James Wolfe Ripley
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Stimulated the development of the Model 1855 rifle-musket
Oscar Mossberg
SOME PIONEERS IN FIREARMS DEVELOPMENT. - The maker of high-quality 22 rifle, sporting rifles and pump action shotguns.
Eugene Stoner
SOME PIONEERS IN FIREARMS DEVELOPMENT. - a talented ex-marine, who became the chief engineer and designer of the Armalite Firearms business company.
Mikhael Kalashnikov
SOME PIONEERS IN FIREARMS DEVELOPMENT. - designed the AK47, an assault rifle in 1947
Henry Derringer
SOME PIONEERS IN FIREARMS DEVELOPMENT. - famous for his pocket pistols. He gave his name to a whole clas of fireams rifles and pistols
Col Calvin H. Goddard
SOME PIONEERS IN FIREARMS DEVELOPMENT. -Father of Modern Ballistics
Fedor Tokarev
SOME PIONEERS IN FIREARMS DEVELOPMENT. Designed the service pistol of the Soviet forces.
Daniel B. Wesson
SOME PIONEERS IN FIREARMS DEVELOPMENT. - An associate or partner of Smith in revolver making
Elisha King Root
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Designed the machinery for making Colt fireams
Horace Smith
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Founded the great firm Smith and Wesson and pioneered the making of the breech- loading rifles
John Mahlon Marlin
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Founder of Marlin Firearms Company
George Luger
SOME PIONEERS IN FIREARMS DEVELOPMENT. - He did lasting design work in Connection with 9mm parabellum cartridge
Samuel Colt
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Produced the first practical revolver
John M. Browning
SOME PIONEERS IN FIREARMS DEVELOPMENT. - Wizard of modern firearms and pioneered the breach-loading single shot rifle
Charles Dochester and George Sullivan-
SOME PIONEERS IN FIREARMS DEVELOPMENT. . formed the Armalite business in 1950, the producer of Colt M16
David "Carbine" Williams
SOME PIONEERS IN FIREARMS DEVELOPMENT.. - Maker of the first known carbine
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SPECIFIC PARTS OF A CASED CENTER-FIRE CARTRIDGE - Head stamp - Primer cup - Priming mixture - Anvil - Flash hole - vent - Rim - Extractor groove true only to pistol and rifle cartridges - Brass case - Shoulder- true only to rifle cartridges - Neck-true only to rifle cartridge -Crimp - Cannelure - lubricant grooves - Metal jacket - Lead core -Nose / tip
REAMING
STAGES OF BARREL MANUFACTURING. It is the process of cleaning or uniformly scrapping the interior surface of the barrel to achieve the desired bore diameter. The reaming instrument removes the metal from the entire surface because its diameter is slightly larger than the driller. Reamers are made of tungsten carbide. This stage produces a smoothbore barrel. After reaming, the bore's surface has good dimensional uniformity from end to end.
DRILLING
STAGES OF BARREL MANUFACTURING. It is the process of making a hole from one end to another end through the center of a steel rod. The result of this stage is a rough hole with almost uniform diameter from end to end of the barrel. The interior surface of the barrel has sears, scratches and chips due to irregular cutting of the drilling instrument. Special driling machines have drills made of tungsten carbide.
.LAPPING
STAGES OF BARREL MANUFACTURING. It is the process of polishing the inner surface of the gun barrel. It simply involves rubbing the bore surface using a polishing compound to remove machining marks and any tight spots in the rifling thus making the bore's surface dimensionally uniform from end to end.
CHAMBERING
STAGES OF BARREL MANUFACTURING. The process which involves cutting wider space at the breech end of the barel that will serve as the chamber for the cartridge ready to be fired.
RIFLING
STAGES OF BARREL MANUFACTURING. This stage is the process necessary for making the helical grooves inside the barrel. This stage produces a barrel with lands and grooves at the interior surface. However, this is not applied in making a smoothbore firearm
brass
STRUCTURE OF CARTRIDGE CASE - Standard cartridges of center-fire ammunitions have a shell that is usually made of ____- 70%copper and 30% zinc.
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Smokeless powders today can be in various shapes. Sheets of smokeless powder are cut into Discs Flakes Balls Tiny cylindrical shapes
PHYSICAL EXAMINATION
TECHNIQUES OF EXAMINATION IN FIREARMS IDENTIFICATION All specimens submitted by the requesting party will be physically examined to determine its markings or initials made by the investigator for identification purposes. All cases that involve fiream identification start with preliminary examinations of the evidence for similar class characteristics.
Microscopic Examination
TECHNIQUES OF EXAMINATION IN FIREARMS IDENTIFICATION? After the recovery of the test bullets and test cartridge cases, known, test fired specimens are compared to questioned specimens using the Bullet Comparison Microscope. Under the bullet comparison microscope, the two fired bullets or fired shells are examined in juxtaposition - that is, the two objects- evidence and the test bullet are examined and compared:(TiP-DIM) - at the same Time - at the same Place or level - at the same Direction - at the same Image - at the same Magnification
1)Terminal Penetration 2)Terminal Accuracy 3)Terminal Velocity 4)Terminal Energy
TERMINAL BALLISTICS This branch of ballistics is concemed with the effects of the impact of the projectile on the target, and this involves the following: (PAVE) __1__ that depth of bullet penetration on the target or object hit .__2__- that size of the bullet group on the target. __3__ velocity of the projectile when it strikes the target. __4__ that energy of the projectile when it strikes the target. It is otherwise refered as the striking force or energy
1)Single-based propellant 2)Double-based propellant 3)Triple-based propellant 4)HIT (high-ignition temperature)
THE 4 MAIN CLASSES OF PROPELLANTS __1__ - This is composed of pure nitroglycerin gelatinized with nitrocellulose __2__ - This type is composed of nitrocellulose and nitroglycerin mixed with any or all of the following minor ingredients: Centralite, Vaseline phathalate, esters, and inorganic salts. __3__ - This is composed of three principal ingredients, which are nitrocellulose, nitroglycerinne, and nitro-guanidine. This type of propellant was developed in attempting to compromise the low-power sing-based propellant and high-power but excessive heat of double base powders. __4__ Propellant The main ingredient of this class of propellant is the RDX (cyclonite) group of high explosives. It was developed by the Dynamite Noble of Germany in conjunction with Heckler and Koch.
Crimp
THE PARTS OF THE CARTRIDGE CASE . -this acts as the lip since it is found at the periphery of the mouth of the cartridge case. It has also two functions: to aid in holding the bullet in place and to resist the initial forward motion of the bullet while the gunpowder undergoes combustion.
Cannelure
THE PARTS OF THE CARTRIDGE CASE. - composed of serrated grooves found at the interior surface of the neck which has a dual function: to serve as lubricant groove and to prevent the bullet from being pushed or pulled.
Vent
THE PARTS OF THE CARTRIDGE CASE. - it is also called flash hole, this part provides a passage of heat and flame from the primer pocket towards the gunpowder chamber.
Rim
THE PARTS OF THE CARTRIDGE CASE. - serves to limit the forward travel of cartridge into the chamber and the clearance between the head are supporting
Shoulder
THE PARTS OF THE CARTRIDGE CASE. - supports the neck of the shell which is true to rifle and machinegun cartridges.
Head stamp
THE PARTS OF THE CARTRIDGE CASE. - the bottom surface of the shell that contains engraved data such as the manufacturer's ID, caliber and year of manufacture.
Extracting groove
THE PARTS OF THE CARTRIDGE CASE. - the circular groove near the base of the shell designed for automatic withdrawal after each firing.
Body
THE PARTS OF THE CARTRIDGE CASE. - This is the 'cork that plugs the breech to prevent gas from escaping at the rear of the gun barrel. For bottleneck shaped cartridges, the cork includes the shoulder and the neck.
Neck
THE PARTS OF THE CARTRIDGE CASE. - part that is occupied by the bullet, which is true for rifle and machinegun cartridges
Base
THE PARTS OF THE CARTRIDGE CASE. - the bottom part of the case that contains the primer rim and head stamp
Primer Pocket
THE PARTS OF THE CARTRIDGE CASE. - used to hold the primer in central position, to prevent gas from escaping to the rear of the cartridge, and to provide solid support of primer anvil.
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TWO TYPES OF JACKETED BULLETS -Full Metal Jacketed - Semi-jacketed
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TYPES OF BALLISTICS PROBLEMS There are six (6) types of problems in Forensic balistic, namely No. Item .Problem 1. Bullet - Determine the caliber and type of firearm from which it was fired. 2. Fired Cartridges Case - Determine the caliber and type of firearm from which it was fired. 3. Bullet and suspected Firearm - Determine whether or not the bullet was fired from the suspected Firearm. 4. Fired Cartridge case and a suspected Firearm - Determine whether or not the cartridge case was fired from the suspected Firearm. 5. Two or more bullets - Determine whether or not they were fired from only one firearm 6. Two or more cartridge case - Determine whether or not they were fired from only one firearm.
TARGET SHOOTING BULLETS
TYPES OF BULLETS BASED ON PURPOSE. - Bullets designed with sharp shoulder to cut clean holes in target paper.
POISONED BULLETS
TYPES OF BULLETS BASED ON PURPOSE. - Theoretically, a caliber.177 bullets (the smallest bullet in general use) can cary enough poison to kill a large animal. A bullet with this caliber can allow small but lethal guns. A protein poison such as alfatoxin or ricin, with tiny lethal doses and easy low-cost availability, is used in tiny assassination weapons in the past.
WAX-BULLETS
TYPES OF BULLETS BASED ON PURPOSE. - These are bullets intended for quickdraw shooting exercise or competition.
FRAGMENTING BULLETS
TYPES OF BULLETS BASED ON PURPOSE. - These are similar to hard ball round with stress lines manufactured into slug. The result is that the bullet splits into fragments when hitting soft tissue, creating a bigger wound. However, they tend to retain their form when penetrating an amored target
HARD BALLS
TYPES OF BULLETS BASED ON PURPOSE. -These bullets have full metal jacket composed of copper sheath over a lead core. These are the standard projectile type, expanding very little, but giving good penetration.
EXPANDING BULLETS
TYPES OF BULLETS BASED ON PURPOSE. These are soft point bullets (mushroom) bullets and hollow point bullets (sometimes called dumdums after the British arsenal in India where they were designed and first manufactured) - have metal jacket at both ends that flattens on contact with living tissue and produce internal damage. All soft bullets, split-nose bullets, hollow-point .bullets, and jacketed bullets with the core exposed at the tip are of this type of bullets. Today, they are used for big-game hunting because of their great stopping power.
FLECHETTE
TYPES OF BULLETS BASED ON PURPOSE. -This is a special type of pointed bullet with an arrow-shaped tip. Spitzer bullet is the tem used by the American and British sportsmen when referring to a pointed bullet
EXPLOSIVE BULLETS/ SAFETY GLAZER SLUG
TYPES OF BULLETS BASED ON PURPOSE. - A type of bullet which would explode if it hits a hard object or target.
Soft point bullet
TYPES OF BULLETS BASED ON PURPOSE. expand on striking an object and therefore produce much serious shock and have more correspondingly greater stopping power when fire from high velocity rifles, these bullets expand upon striking a flesh until it looks like a mushroom. However, bullets of these kinds when fired from handguns have lesser penetrating effect than full jacketed bullets because velocity is too law to cause the bullet to expand.
ARMOR PIERCING BULLETS
TYPES OF BULLETS BASED ON PURPOSE. - These are bullets designed to perforate thin layers of armor and retain enough velocity to injure personnel or destroy equipment. Amor-piercing bullets for small arms are of similar material to the standard bullets. However, in addition to lead and antimony / filler, they have hardened steel (tungsten chrome steel) cores.The hardened steel core continues to penetrate the armor after the jacket and filler have been stripped away by contact with a resistant surface.
RUBBER BULLETS
TYPES OF BULLETS BASED ON PURPOSE. -Designed to be non-lethal, usually Used in riot control.
INCENDIARY BULLETS
TYPES OF BULLETS BASED ON PURPOSE. These are military bullets used for starting fires in inflammable targets. They certain mixture of phosphorous and other chemicals that can be set on fireupon firing the target. They are used against targets socks aircrafts or gasoline depot.
HOLLOW-POINT BULLETS
TYPES OF BULLETS BASED ON PURPOSE.. sometimes called express bullets, have cavity in the nose designed to increase the expansion when they hit their target. They are designed to provide rapid expansion while soft-points are designed to provide deeper penetration before expansion. However, this performance may vary depending on the design of the bullet and the impact velocity.
X-BULLETS
TYPES OF BULLETS BASED ON PURPOSE.. -These are solid copper projectiles, heat treated for extra toughness with no separate jacket or leadcore.These bullets are famous for deep dependable penetration. A deep forward cavity causes the nose to peel back into four razor-edge petals. Viewed in front, the appearance of the four petals gives the x-bullet its name.
ICE BULLETS OR SOLIDIFIED BULLET -
TYPES OF BULLETS BASED ON PURPOSE.. Super cooled water made as a projectile
TRACER BULLETS -
TYPES OF BULLETS BASED ON PURPOSE.. These are bullets that have chemical compound (usually barium nitrates) at the base that burns brightly so the shooter can observe its path. There are special pistol traces bullets with which downed aviators can signal their positions. Usually this is a mixture of magnesium, perchlorate, and chromium, to yield a bright red color. A new design involves the use of LED, but the cost and complexity would seem to negate any advantage.
BOXER PRIMER
TYPES OF PRIMER. - American type - Has a single vent. - Its anvil is V-shaped separate little piece of brass, thus this is also called separate anvil type. - The flash hole is located at the center of the primer Cup. - The Boxer type primer was developed by Colonel Edward Munier Boxer and was patented in June 29, 1869. Although the process of manufacturing it seems to be quite difficult, it became more popular because of its adaptability in reloading cartridge cases.
BERDAN PRIMER
TYPES OF PRIMER. - European type. - It was invented by Hiram Berdan and was patented in March 20, 1886. - The anvil, which is actually a part of the cartridge case, is sticking out from the center of two or three flash holes - Special tool is required to remove the primer. Thus, Berdan primed shells are not generally reloaded.
Rimmed case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO RIM. - designed for cartridges of revolvers, shotguns and some single shot rifles. This the earliest type of shell. The diameter of the cartridge base is wider than the diameter of the body
Sémi-rimmed case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO RIM. - designed to combine the advantages of the rimmed and rimless casing. However, it never became popular.
Rimless case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO RIM. - has a base with the same diameter as that of the body. This case design allows smooth feeding from magazine to the chamber. The case length and shoulder allow proper head spacing.
Belted case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO RIM. -attempts to combine the smooth feeding characteristics of the rimless case with the consistent head spacing of the rimmed hell. Most common usage is in the magnum rifles cases. The belted case was designed to provide positive head spacing and allow magazine feeding.
Rebated case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO RIM. -developed to allow a firearm to fire a new cartridge with a bigger caliber using existing bolt of standard design but smaller caliber. In other words, the rebated shell a body with a wider diameter compared to its rim.
Bottleneck case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO SHAPE. - always true to rifle ammunition. This is the casing of most modern center-fire rifle ammos. This is the type of shell that provided the greatest power capacity commensurate with overall case length.
Straight case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO SHAPE. true to pistol and revolver ammunition. This is the casing of all rimmed cartridges for revolvers and all center-fire pistol ammo that are now manufactured.
Tapered case
TYPES OF SHELLS/CARTRIDGE CASE ACCORDING TO SHAPE. - an obsolete type of case. It is very rare but presently being used in magnum jet cartridge of caliber .22 firearms.
1)Long-barreled weapons 2)Short-barreled guns
TYPES OF SMALL ARMS ACCORDING TO BARREL LENGTH (LS) -__1__- designed for long-range shooting Ex. shoulder firearms and high-caliber machineguns - __2__ - accurate only at relatively short ranget Ex. pistols, revolvers and submachine guns
FORENSIC BALLISTIC
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. Today, it is frequently used synonymously in the press and in the Police Parlance to Firearms ldentification.
1)Penetration Potential 2)Wound ballistics
Terminal Balistics is the study of bullet penetration in solid and liquids. It can be subdivided into 1. __1__, which is the capacity of a bullet to penetrate various materials 2. __2__ , which is the effect the bullet has on living tissue.
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The characteristics of firearms are influenced by three principal factors, which are as follows: (DMM) - Design of the gun as established by the manufacturer - The Manner how the fiream is used - Gun Manufacturing process
Test Firing
The firearm is fired from a bullet recovery box or water tank in order to obtain test bullets and test cartridge cases Note: for conclusiveness of findings, there shall be atleast three test bullets that should be compared. - First, for Comparison/preliminany - Second, for Confimation - Third, for Conclusion
CLASS CHARACTERISTCS OF FIREARMS
The intentional or design characteristics that would be common to a particular group or family of fireams. These are characteristics that are determined even before the firearm is manufactured. All cases that involve firearms identification start with preliminary examination of the evidence for similar class characteristics. Firearm class characteristics may be determined from any of the following: (F-BUS) - The Firearm itself - Fired Bullet - Unfired cartridge - Fired Shell
center-fire cartridges.
The priming mixture is usually made of lead styphnate, barium nitrate, and antimony sulfide Lead, barium and antimony elements are typical in primers of ____
STEYR TYPE
The rifling in firearms may be divided into the following types: - 4 lands, 4 grooves, Right hand twist, Lands and Grooves of equal width (4R, G=L). It is used in earliest self-loading pistols.
ÁRMY TYPE
The rifling in firearms may be divided into the following types: - 4 lands, 4 grooves, Right hand twist, narrow lands and broader grooves (4R, G3x)
SMITH AND WESSON TYPE
The rifling in firearms may be divided into the following types: - 5 lands, 5 grooves, Right hand twist, Lands and Grooves of equal width. (5R, G=L)
BROWNING TYPE
The rifling in firearms may be divided into the following types: - 6 land, 6 grooves, Right hand twist, narrow land and broader grooves. (6R, G2x)
COLT TYPE
The rifling in firearms may be divided into the following types: - 6 lands, 6 grooves, Left hand twist, narow land and broader groove. (6L, G2x)
WEBLEY TYPE
The rifling in firearms may be divided into the following types: - 7 lands, 7 grooves, Right hand twist, narrow land and broader groove. (7R, G3x)
KEY HOLE SHOT
The tumbling of a bullet in its flight and hitting the target sideways as a result of spinning on its axis
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There are two main types of gunpowder; the black powder and the so-called smokeless powder.
1)Corrosive primer 2)Non-corrosive primer
Two classes of modern priming mixture: __1__ - primarily composed of potassium chlorate. If this is ignited, it produces potassium chloride which draws out moisture from the air and this moisture speeds the corrosion of metal. Its ingredients are: - Potassium chlorate-45% (initiator and fuel) - Antimony sulfide -23% (fuel element) - Mercury fulminate -32% (initiator) __2__ This is the improved class of priming mixture. It has barium nitrate instead of potassium chlorate.
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Types of motion. - the straight motion of the bullet where there is no rotation.. It includes the bouncing of bullet after hitting a hard object.
Rotary
Types of motion. - the spinning motion of the bullet as a result of the riflings.
Direct
Types of motion. - the forward motion of the bullet inside the barel as a result of gas expansion.
1)HOMEMADE 2)AIR GUNS
UNUSUAL OR MISCELLANEOUS TYPE CLASSES OF FIREARM - __1__- Those types of fire arm that is unique in mechanism and construction like Paltik - __2__ - These are firearms which use pneumatic pressure to fire a projectile
1)cartridge 2)ammunition 3)Shell 4)Cartridge
What is AMMUNITION? Technically, the term __1__ is used to describe a complete unfired unit consisting of bullet, cartridge case propellant, and primer. Legally speaking, __2__ refers to any loaded shell for rifles, muskets, carbines, shotguns, revolvers, and pistols from which a bullet, ball, shot, shell or other missiles maybe fired by means of gunpowder or other explosives.The term also includes ammunition for air rifles. (Section290 of the National Internal Revenue Code; Section 877 of the Revised Administrative Code) __3__ - ammunition for large caliber guns __4__- ammunition for rifles and handguns
1)Ballo 2)Ballein 3)Ballo or Ballein 4)Ballista
What is Ballistics? It is the science of motion of projectile and the condition governing that motion. The word "Ballistics" was originated from the Greek word "__1__" or "__2__". __3__ means to throw and from a Roman war machine called "Ballista" __4__- 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.
Smokeless powder
allowed the development of modern semi-and-full automatic firearms. There are two main advantages of this powder over black powder. Minimal smoke is produced when smokeless powder is burned. It is much more powerful than black powder giving an accurate rifle range of up to 1000 yards.
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 limitéd 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)
Firearms identification
can be defined as the systematic identification of fired bullets, fired cartridge cases, or other ammunition components as having been fired from a specific firearm.
Black powder The three disadvantages of black powder that were tolerated before the invention of modern gunpowder as follows: (SFM) - It produces large cloud of white Smoke. - It leaves a thick, heavy Fouling which is both- hygroscopic and corrosive. - It attracts Moisture hence it must be stored properly.
can be prepared following this optimum proportion: - 11.85% sulfur, This is main fuel component of the gun powder.- -74.64% saltpeter Scientifically known as KNO3 (potassium nitrate) -13.51% carbon
Cut-Rifling Technique
four types of rifling technique . : - Also called hook-cutter system, this technique is described as the single point broaching system. This is the oldest method as it was invented in Nuremburg, Germany sometime in 1492 which requires the use of "hook' cutter. In this rifling technique, grooves are cut individually one at a time
Broaching
four types of rifling technique. In this technique, all the grooves are cut at once by means of a long progressively stepped cutter that pulled through the barrel. This is much faster than the preceding technique because all the grooves are cut at the same time. This technique is usually used in making volumes of military firearms. It produces gun barrels that have rougher interior Surface as compared to barels produced by cut rifling technique. Modern broaching tool is are about 16 inches long with several cutting rings that is why they are called gang broaches.
Button Rifling
four types of rifling technique. This 'is done by forcing a carbide tool with button made of very hard steel plug through the bore. This technique is fairly fast and generally produces smoother finish than cut-rifling technique or broaching process however, it does not provide a uniformly controlled twist.
Hammer Rifling
four types of rifling technique. This technique was developed by the Gemans before the 2nd world war. The first hammer rifling machine was built in Erfurt, Gemany in 1939.
firearm
is a mechanical device that uses pressure from a burning powder to force a projectile through and out of a metal tube
PRIMING MIXTURE
is a volatile (highly sensitive) chemical in powdered form contained in the primer cup. Once its volume is compressed, it automatically undergoes rapid combustion.
Firearms identification
is mostly concerned with the examination of the characteristics left by the firearm on any ballistics related evidence, These are features/traits of the Firearms that can be transfered to the ammunitions fired through them and are used to identify them
SHOTS BALLISTICS
it deals with the attributes and properties of shots and pellets. When a shot shell is fired from a shotgun, the pellets leave the barrel and begin to spread or scatter. the farther the pellets travel, the greater the spread of shot. Shotgun barrels have a choke to control the spread or shot pattern
MAGNUM AMMUNITION
may refer to the powder charge or the case design. As compared to regular ammunition, magnum ammunition has more powder charge than the former.
INDIVIDUAL CHARACTERISTICS OF FIREARMS
refer to those characteristics that are determinable only after a gun is finally manufactured. The individual characteristics of firearms can be transferred to: (BCC) - Bullets - Cartridge Case - Primer Cup
1)flakes
term smokeless powder is a misnomer for this propellant is neither a powder nor smokeless. Most smokeless powder used as propellant appears as __1__. When they are burned, they produce smoke but not as many compared to huge cloud of white smoke produced by black powder.