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Review on ballistics (2014)


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Reviewer for licensure examination for criminologist

Published in: Science

Review on ballistics (2014)

  1. 1. Philip B. Magtaan, Reg. Crim., MS Crim
  2. 2. Ballistics Chapter 1
  3. 3. DEFINITION OF BALLISTICS • In its broadest sense, ballistics is defined as is the science dealing with the motion of projectiles and the conditions governing that motion. Science is a systematized body of knowledge which has been observed tested and proven. Motion refers to movement or mobility. • 3 Types of Motion • Direct motion – is the forward movement of the bullet or shots out of the shell by the action of the expansive force of gases from a burning gun powder. • Gyroscopic motion – is the action of the bullet passing through a rifled bore barrel firearm which is either twisted to the left or right. • Translational – is the action of the bullet once it hits a target and subsequently ricocheted.
  4. 4. • Projectile means to metallic and non-metallic object propelled by means of force. In strict sense, it is the study of natural laws relating to the performance of gunpowder and projectiles in firearms and the means of predicting such performance. It is also refers to the science of firearms identification which involves the scientific examination of ballistics exhibits (fired bullets, fired shells, firearms and allied matters) used in crimes involving scientific equipments such as bullet recovery box, bullet comparison microscope and others.
  5. 5. ETYMOLOGY • The term ballistics was derived from the Greek word “ballo” or “ballein” which literally means “to throw”. Its root word was also said to have been derived from the name of an early Roman war machine called “ballista” - a gigantic bow or catapult which was used to hurl missiles or large objects such as stones at a particular distance to deter enemy forces. The term ballistics is frequently used synonymously in the press and in police parlance to firearm identification and investigation.
  6. 6. BALLISTICS AS A SCIENCE • Ballistics is classified, formulated and verifiable knowledge gathered by observation, research and experiment and based on scientific theory and using scientific equipment and apparatus. Results of firearms identification is an exact science because it permits an absolute precision in results free from possibility of error normal to human perception. Therefore, ballistics per se is not an exact science rather it is a branch of physics or applied science which is subject to changes and development depending upon the demands of the modern civilization.
  7. 7. EARLY RECORDED FIREARMS IDENTIFICATION • The earliest recorded identification of firearms by the trained observer was recorded in the criminal investigation by Hans Gross, the great Austrian Criminologist and considered as the father of criminalistics. This refers to the French bullet fired by soldier of Napoleon Bonaparte’s Army, which lodge behind the eye of his grandfather in 1799. The bullet was recovered in 1845 after the death of his grandfather. When Hans Gross saw it, he observed and found out that it was still with traces of gunpowder and this would prove evidentiary value. • Another was done by Charles Waite in the United States of America. He was an employee of New York State who conducted an investigation involving firearms. In 1915, a farmer was accused of murder with a gun. Waite was not convinced by the evidence of the firearms’ experts, and his effort showed that the accused is innocent. Through Waite’s effort, to trace the gun from which the bullet was fired, consequently identify the manufacturer of the gun.
  8. 8. • Alexandre Lacassagne (1844-1921)- was the first to recognize the significance of the striations etched found on a bullet extracted from a murder victim and its to link to the gun from which it was fired, thus beginning the science of ballistics. • Edmond Locard (1877-1966) – established the first forensic laboratory in France. His principles “objects or surfaces which came into contact always exchange trace evidence”. • Col. Calvin H Goddard (1920) – pioneered the introduction of science of Ballistics in the different universities in U.S., subsequently it was universally practiced and accepted in the different courts throughout the world.
  9. 9. FORENSIC BALLISTICS • Forensic – a term originated from the Latin word “forum”, meaning “marketplace where people gather for public disputation or public discussion”. • Forensic Ballistics – it refers to the science of investigation and identification of firearms and ammunition used in crimes. • It is a refined Tool Mark Identification where the firearm is made of a material harder than the ammunition components, acts as a tool to leave impressed or striated marks on the various ammunition components that come into contact with the harder surface of the firearm. • Dr. Albert Llewellyn Hall, the pioneer in the field in forensic ballistics, was an expert in identifying firearm from the fired bullets. Identification of the crime gun is in the principal purpose and objectives of criminal investigation, to establish the identity of criminal offender and assist in their prosecution.
  10. 10. BRANCHES OF BALLISTICS • 1. Interior (internal) Ballistics • It refers to the properties and attributes of the projectile while still inside the gun. It covers from the time; the firearm is loaded with the cartridge, the explosion and the movement of the bullet from the breech to the muzzle of the gun.
  11. 11. ATTRIBUTES OF INTERIOR BALLISTICS • Firing pin hitting the primer • In order that the primer should explode, the firing pin should hit such. This is due to the theory of friction wherein there is a resistance to motion created by the firing pin. • Ignition of the priming mixture • Priming mixture is made up of very sensitive material that is commonly located in the center portion of the cartridge case. In order to ignite the priming mixture, it must be live and potent and must be devoid of any moisture. • Combustion of the gunpowder • As the primer crushed and ignited, the flash passes through the vent towards the gunpowder that provides the combustion of gunpowder.
  12. 12. • Expansion of the heated gas • There will be equal expansion of heated gas inside the cartridge, after the combustion of gunpowder. The gas expanded in the different direction that tends the bullet and shell to separate from each other in the cartridge. • Pressure developed • When the heated gas created by the burning powder charge is developed, a tremendous pressure is produced in the chamber of the firearm. • Energy generated • Energy refers to the fatal equivalent of a bullet compared to a pound that is drops from a certain height.
  13. 13. • Recoil of the gun • The recoil of the gun is due to the Newton’s third law of motion (law of interaction) which states that in every action is always equal and opposite reaction. The forward movement of the bullet after the explosion results to backward movement of the cartridge case. Recoil of the gun is affected by several things such as tightness with which the firearm is held, height of the bore above the center of the stock line of wrist for pistols, shape and design of the butt plate or the pistol’s grip, weight of the firearm and the physical and mental condition of the shooter.
  14. 14. • Velocity of the bullet in the gun • The bullet will travel the bore of the barrel depending on the powder load of the cartridges, since it is the powder load that will propel the bullet in the bore of the barrel of the firearm. • Rotation of the bullet in the barrel • When the bullet is driven by the heated gas by tremendous pressure towards the muzzle end, the bullet will rotate following the riflings inside the gun barrel. But if the firearm does not have riflings inside the barrel, the bullet (shot) would just move forward without rotating inside the bore of the barrel until the bullet left the gun muzzle.
  15. 15. • Engraving of the cylindrical surface of the bullet • The riflings starting from the breech end up to the muzzle end of the barrel will engraved in the body of the bullet, depending on the number of lands and grooves as part of the class characteristics of the firearm.
  16. 16. 2. EXTERIOR (EXTERNAL) BALLISTICS • It refers to the attributes and movements of the bullet after it has left the gun muzzle, which includes the condition of the bullets’ movement and flight up to the target.
  17. 17. ATTRIBUTES OF EXTERIOR BALLISTICS • Muzzle blast – it is the noise created at the muzzle point due to sudden escape of the expanding gas coming in contact with the surrounding atmosphere. Due to this sound at the muzzle end of the gun, a silencer was invented to minimize the sound, which the criminal took advantage to conceal the crime. • Muzzle energy – it is an energy generated at the muzzle point, whenever the cartridge explodes from a firearm. • Trajectory – actual curve path of the bullet during its flight from the gun muzzle to the target. There are three stages of trajectory namely, straight horizontal line, parabola like flight and vertical drop.
  18. 18. • Range – straight distance from the muzzle to the target. It is classified into: 1. Accurate /maximum effective range – it is the distance within a shooter has control of his shots. 2. Absolute maximum range – it is the farthest distance that a projectile can be propelled from a firearm. It is based upon the intrinsic accuracy of the firearm and ammunition, size of the target, marksmanship ability of the shooter, the ability to discern the target, knowledge of the ballistics characteristics of the ammunition, and the level of power needed to be delivered to the target. • Velocity – rate of speed per unit time.
  19. 19. • Air resistance/aerodynamic drag – resistance encountered by the bullet during its flight which reduces its speed. There are three parts of drag bullet, the bow resistance, skin friction and the base drag. • Pull of gravity – downward reaction of the bullet towards the center of the earth, due to its weight. The pull of gravity will apply only, starting from the parabola, then to the maximum range and to the final vertical drop. However, in the effective range, the bullet could withstand the pull of gravity due to its velocity and gyroscopic stability. • Penetration – depth of entry on the target based on the power and velocity of the bullet.
  20. 20. 3. TERMINAL BALLISTICS • It refers to the effects of the impact of the projectile in the target. The knocking power of particular powder load of the cartridges which makes a devastating lesion, caused by the bullet.
  21. 21. ATTRIBUTES OF TERMINAL BALLISTICS • Terminal accuracy – it is the size of the bullet grouping on the target. • Terminal energy/striking energy – it is energy of the projectile when it strikes the target. This refers to the fatal equivalent of a bullet when it struck the victim. • Terminal velocity – it is the speed of the bullet upon striking the target. • Terminal penetration – it is the depth of entry of the bullet in the target.
  22. 22. 4. FORENSIC BALLISTICS • It refers to the investigation and identification of firearms by means of ammunition fired through them. This is the real branch of the science which the police use as their guide in field investigators.
  23. 23. ATTRIBUTES OF FORENSIC BALLISTICS • Field investigations – it is conducted the first responders when they investigate a case wherein firearms have been used. • Technical examinations of ballistics exhibits – it is conducted by the firearms examiners in the ballistics laboratory to determine the value of firearms exhibits in the solution of the case. • Legal proceeding – it includes making of ballistics report and presentation of the result of the examination conducted before the court.
  24. 24. 5. SHOT BALLISTICS • It is the study of shotgun ammunition including its characteristics spread and trailing. 6. Wound Ballistics It refers to the study of the effects of a projectile on a target and the conditions that affect them
  25. 25. Scientific Equipment Used in Firearms ID Chapter 2
  26. 26. INTRODUCTION • By means of these equipment and with qualified men to use them, the police will be more effective in their drive against crimes involving firearms. At times, an insignificant fire bullet or shell found at the crime scene will serve as the only “missing link” in the final solution of a crime wherein a gun has been used. And this is brought out to light only in the laboratory by the use of different equipment. It includes:
  27. 27. 1. BULLET COMPARISON MICROSCOPE • It is designed to permit the firearm examiner to differentiate two fired bullet or shell, by simultaneously observing their magnified image in a single microscopic field. Fired bullet and shell are examined and compared in either INTERMARRIAGE (half of the same image of the evidence bullet/shell and half of the same image of the test bullet/shell of the same direction, the same magnification, and the same level or plane are merge into one image to look for the congruency of stations or the same markings) and in JUXTAPOSITION (critical side by side comparison at the same time, direction, magnification, image and level or plane to find the same feature, structure of striations to the specimens under observation).
  28. 28. • The forensic examiner can take photomicrographs which are needed for court presentations as an exhibit to support the ballisticians’ findings he observed under this instrument. The photomicrograph will give a clue to the judge how the ballistician arrived with his findings and conclusions. • It was introduced by Dr. Calvin H. Goddard on April 1925. He was the first to own and use the first bullet comparison microscope, and through his efforts, he is considered as the father of modern ballistics. He took active participation in the examination of the fired shells in the infamous General Castañeda and Salgado Ambuscade in Quezon City.
  30. 30. 2. STEREOSCOPIC MICROSCOPE • It is generally used in the primary examinations of fired bullet and shells to determine the relative distribution of the class characteristics or for orientation purposes. It can also be used in the closed-up examination of tampered serial numbers of firearms. • In the middle of 19th century, Francis Herbert Wenham of London designed the first successful stereomicroscope. The first modern stereoscopic microscope was introduced in the United States by Cycloptic.
  32. 32. 3. SHADOWGRAPH • It contains a series of microscopic lenses of different magnifications that can be used in examining fired bullets or fired shells to determine the class characteristics and also for orientation purposes. This instrument contains a large circular ground glass, and a diameter about 14 inches, wherein the observation and comparison of class characteristics is dome similarly with the bullet comparison microscope.
  34. 34. 4. CP-6 COMPARISON PROJECTOR • Similar to bullet comparison micro-scope in which two fired bullets of shell can be compared simultaneously by projecting the image on a large screen and is observed at a vertical and comfortable viewing. • The instrument was invented by William Howard Livens, an engineer and British army.
  36. 36. 5. BULLET RECOVERY BOX • It used is to obtain test fired bullets or test fired shells for examination and comparison to the questioned bullets or shell. Several designs of bullet recovery box are now adopted, for as long as it could meet the desired result in test firing and retrieved the fired bullet undamaged. This is commonly filled with cotton but sometimes water tank, sawdust with oil, sand, waste threads, darak, banana trunks or rubber strips can be used and separated by cardboards.
  38. 38. 6. HELIXOMETER • It is used in measuring pitch of riflings of firearms. This instrument is generally used in highly advanced ballistics laboratory. With this instrument, it is possible to measure the angle of twist in a rifled pistol or revolver barrel. It is used in inserting the telescope and aligning it with the axis of the bore. The scope is mounted in a rotatable bearing, with a graduated disc which permits reading circular measurements to three minutes of an arc. • This instrument was invented by John H. Fisher.
  39. 39. 7. MICROMETER/CALIPER • This is used in making measurements such as bullet diameter, bore diameter, barrel length and other important details.
  40. 40. 8. ANALYTICAL OR TORSION BALANCE • Used for determining weights of bullets or shotgun pellets – for possible determination of type, caliber and make of firearms from which fired.
  41. 41. 9. ONOSCOPE • A small instrument that is sometimes used in examining the internal surface of the gun barrel with a tiny lamp at the terminal portion and this is inserted inside the bore for internal examination.
  42. 42. 10. TAPER GAUGE • Used primarily for determining the bore diameter of firearms.
  43. 43. 11. SCANNING ELECTRON MICROSCOPE • A high powered electron microscope used to identify left over particles like gunpowder residues and primer residues. This is a computer system combined with an electron microscope and laser spectrophotometry unit. Its power is so great that with a mere speck of dust it could identify the elemental components of the particle under examination.
  45. 45. 12. ELECTRIC GUN MARKER/STYLUS • Used in the laboratory for marking fired bullets, fired shells and firearms submitted for examination.
  46. 46. 13. CHRONOGRAPH • It is used to measure the speed of bullet. • It was invented by Alfred Lee Loomis in 1918.
  47. 47. 14. BULLET PULLER • It is used to separate the bullet form the cartridge case.
  48. 48. 15. COMPUTERIZED COMPARISON MICROSCOPE • It is similar to the bullet comparison microscope; the only difference is the magnified image is seen in the monitor. It is more convenient to use than a manual one.
  49. 49. Firearms Chapter 3
  50. 50. HISTORY OF FIREARM The development of firearms followed the invention of gunpowder in Western Europe in the 13th century. Many stories have been told about the discovery of gunpowder, but most are legendary and have little support facts. It also often that gunpowder was first invented by the Chinese and that the Arabs, with their advance knowledge of chemistry at that time, may have developed it independently.
  51. 51. One of the earliest recorded uses of firearms in warfare was an attack in Seville, Spain in 1247. History also showed that cannons were used by King Edward III of England in Crecy in 1346 and by Mohammed II of Turkey in his famous conquest of Constantinople in 1453. The first firearm were inefficient, large and heavy, making it difficult for common soldier to carry; and later the development of small arms weapons were rampant. It was many years later before the use of gunpowder was applied to a portable arm which could be operated by single person.
  52. 52. MEN BEHIND FIREARM Roger Bacon – an English monk and scientist who credited for the invention of gunpowder in 1248. Berthold Schwartz – credited for the application of gunpowder for the propelling of a missile in the early 1300s.
  53. 53. COL. CALVIN HOOKER GODDARD (1891–1955) He was a forensic scientist, army officer, academic, researcher and a pioneer in forensic ballistics. In 1925 Goddard wrote an article for the Army Ordnance titled "Forensic Ballistics" in which he described the use of the comparison microscope regarding firearms investigations. He is generally credited with the conception of the term "forensic ballistics", though he later admitted it to be an inadequate name for the science. He was considered as the father of forensic ballistics.
  54. 54. HORACE SMITH (1808-1893) He was a gunsmith, inventor, and businessman. He and his business partner Daniel B. Wesson formed two companies named Smith & Wesson, the first of which was financed in part by Oliver Winchester and was eventually reorganized into the Winchester Repeating Arms Company Smith was employed by the U. S. Armory service from 1824 to 1842, when he moved to Newton, Connecticut. He was employed by various gun makers up to the 1840s, when he moved to Norwich, Connecticut. He is then listed as a partner of Cranston & Smith. It is known that while in Norwich, he engaged in the manufacture of whaling guns and he is credited with the invention of the explosive bullet used to kill whales.
  55. 55. DANIEL BAIRD WESSON (1825 – 1906) He married Cynthia Maria Hawes, May 26, 1847 in Thompson, Connecticut. He partnered with Horace Smith in Norwich, Connecticut in the early 1850s to develop the first repeating rifle, the Volcanic rifle. He is an associate or partner of Smith in revolver making.
  56. 56. JOHN MOSES BROWNING (1825 – 1926) He was an American firearms designer who developed many varieties of firearms, cartridges, and gun mechanisms, many of which are still in use around the world. He is the most important figure in the development of modern automatic and semi-automatic firearms and is credited with 128 gun patents—his first was granted October 7, 1879. Browning influenced nearly all categories of firearms design. He invented or made significant improvements to single-shot rifles, lever action rifles, and slide action firearms. His most significant contributions were in the area of autoloading firearms. He developed the autoloading pistol by inventing the slide design found on nearly every modern automatic handgun. He also developed the first gas-operated machine gun, the Colt-Browning Model 1895—a system that would surpass recoil operation in popularity. Other successful designs include the M1911 pistol, the Browning .50 caliber machine gun, the Browning Automatic Rifle, and a ground- breaking semi-automatic shotgun, the Browning Auto-5.
  57. 57. DAVID “CARBINE” WILLIAMS He was the maker of the first known carbine.
  58. 58. ALEXANDER FORSYTH (1768-1843) He was a Scottish Presbyterian clergyman who invented the percussion ignition. He was educated at King's College, Aberdeen, and succeeded his father as minister of Belhelvie in 1791. While hunting wild duck he was dissatisfied with his flintlock fowling-piece due to its hang-fire; by the time the bullet was discharged the duck had time to dive before the shot reached them. He patented his scent-bottle lock in 1807; this was a small container filled with fulminate of mercury
  59. 59. ELISHA KING ROOT (1808–65) He was the inventor, engineer, manufacturer; born in Ludlow, Mass. In 1849 he became superintendent of the Colt Firearms Company, eventually becoming president. He remained there until his death. Root invented a drop hammer in 1853, which was soon used in every forge. He also invented a revolving cylinder firearm and developed numerous machines for tooling firearms.
  60. 60. ELIPHALET REMINGTON (1793 – 1861) He was born in 1793 in the town of Suffield, Connecticut, to parents whose origins lay in Yorkshire, England. He was a blacksmith, and at 23, he hand-made a revolutionary sporting rifle using a firing mechanism bought from a dealer, producing the barrel himself. The gun received such an enthusiastic response that Remington decided to manufacture it in quantity, and formed the firm of E. Remington and Sons, which he headed until his death in 1861 . By the mid-1800s the gun had become immensely popular with American sportsmen and was one of the standard guns used in what has been called "the winning of the West". The company continued to grow and to develop its product and gradually began the manufacture of other sporting goods, such as bicycles. At the present time, the company is known as the Remington Arms Co., Inc.
  61. 61. JOHN MAHLON MARLIN (1836 - 1901) He was an American firearms manufacturer and inventor. Marlin was born in Boston Neck, near Windsor Locks, Hartford County, Connecticut as the son of Mahlon Marlin and Jennette Bradford. He worked at the Colt plant in Hartford during the Civil War. Starting in 1863, he made pistols in New Haven, Connecticut, expanding into manufacturing pistols and then different types of firearms by 1872, then called Marlin Fire Arms Company, today Marlin Firearms. Initially producing single-shot weapons only, his company started manufacturing lever-action repeating rifles in 1881.
  62. 62. JAMES WOLFE RIPLEY (1794 –1870) He was an American soldier, serving as a brigadier general in the Union Army during the Civil War. He was instrumental in the early days of the war in modernizing the artillery's ordnance. However, Ripley also delayed the introduction of repeating rifles into U.S. arsenals, an act has been widely criticized by later historians.
  63. 63. SAMUEL COLT (1804 - 1862) He was an American inventor and industrialist. He was the founder of Colt's Patent Fire-Arms Manufacturing Company (now known as Colt's Manufacturing Company), and is widely credited with popularizing the revolver. Colt's innovative contributions to the weapons industry have been described by arms historian James E. Serven as "events which shaped the destiny of American Firearms. Colt never claimed to have invented the revolver, as his design was merely a more practical adaption of Collier's revolving flintlock, which was patented in England and achieved great popularity there.
  64. 64. HENRY DERINGER (1786 – 1868) He was an American gunsmith. He invented, and gave his name to the Deringer pistol. Further development and copying of his design resulted in the derringer (note the double-r) pistol that was generically manufactured widely by other companies. He was born in Easton, Pennsylvania on Oct. 26, 1786 possibly to Johannes Heinrich (and Maria Catherina) Thuringer. However, no family tree entry indicates that the senior Deringer had a son named Henry. He may have been born to Henry Deringer, Sr., a colonial gunsmith who made Kentucky Rifles (and Catherine McQuety Deringer). He married Elizabeth Hollobush at the First Reformed Church in Philadelphia, Pennsylvania on April 5, 1810. He gave his name to the whole class of firearms (rifles and pistol).
  65. 65. JOHN T. THOMPSON • pioneered the making of Thompson SMG.
  66. 66. HIRAM MAXIM (1858) built the first fully automatic gun and the silencer.
  67. 67. • Richard J. Gatling – patented his design of the "Gatling Gun", a six-barreled weapon capable of firing a (then) phenomenal 200 rounds per minute. • Oscar Mossberge – maker of high quality caliber .22 rifle, sporting rifle and pump action shotgun. • Fedor Tokarev – designed the service pistol for Soviet forces. • Carl Walter – developed a reliable small caliber automatic pistol in 1866. • George Luger – designed the 9mm parabellum and cartridge. • Eugene Stoner – designed the M16 assault rifle. • Joseph Laumann – invented the first automatic handgun.
  68. 68. DEFINITION • The term “firearm” has two definition – legal as well as technical. • Legal definition – it may be found in Section 877 of Revised Administrative Code as well as in Section 290 of National Internal Revenue Code and this runs as follows: • • Firearms or arms are herein used, includes rifles, muskets carbines, shotguns, pistols, revolvers and all other deadly weapon from which bullets, balls, shots, shells or other missiles may be discharged by means of gunpowder or other explosives. This term also includes air rifles except such as being of small caliber and of limited range use as toys. The barrel of any firearms shall be considered a complete firearm for all purposes thereof.
  69. 69. • While Republic Act 10591, it is define as: • Firearm refers to any handheld or portable weapon, whether a small arm or light weapon, that expels or is designed to expel a bullet, shot, slug, missile or any projectile, which is discharged by means of expansive force of gases from burning gunpowder or other form of combustion or any similar instrument or implement. For purposes of this Act, the barrel, frame or receiver is considered a firearm. • • Technical definition – a firearm is an instrument used for the propulsion of projectiles by means of expansive force of gases coming from the burning gunpowder.
  71. 71. THE MAIN PARTS A. Revolver C. Rifle 1. barrel assembly 1. barrel assembly 2. cylinder assembly 2. magazine assembly 3. frame or receiver 3. stock group B. Pistol D. Shotgun 1. barrel assembly 1. barrel assembly 2. slide assembly 2. magazine assembly 3. frame or receiver 3. stock group
  72. 72. Hammer Hammer Spur Rear Sight Top Strap Barrel Front Sight Muzzle Ejector Rod Trigger Guard Trigger Grip Panel Cylinder Release / Thumb Latch Cylinder Frame Chamber Extractor Rachet
  73. 73. ACTIONS OF REVOLVER • Single-action revolvers - the trigger performs only one task, when the trigger is pulled the hammer falls, firing the handgun. • Double-action revolvers - as the trigger is pulled two actions occur. The hammer comes back and falls forward to fire the handgun.
  74. 74. Hammer Slide Ejection Port Muzzle Mainspring Cap Frame Trigger Guard Trigger Grip Safety Magazine Front Sight Rear Sight Slide Lock Magazine Release Button Thumb Safety Barrel
  75. 75. ACTION OF PISTOLS • Semi-auto operation When the pistol is fired, the slide moves to the rear, ejecting the spent cartridge and usually cocking the pistol in the process. The cartridges located in the magazine are forced upward by the magazine spring into the path of the slide. When the slide (under pressure from the recoil spring) moves forward, it picks up and pushes the next cartridge into the chamber, ready to be fired again. • Automatic operation The firearm can fire continuously as long as the trigger is pulled. • Selective These fires either on automatic or semi-automatic by using the selector level of the firearm. Ex. Glock Pistols
  76. 76. Charging Handle Rear Sight Drum Carrying Handle Ejection Port Front Sight Assembly Barrel Bayonet Stud Magazine Release Button Dust Cover Trigger Guard Trigger Forward Assist Button Rubber Recoil Pad Flash Suppressor Gas Cylinder Upper Sling Swivel Handguard Bolt Catch Pistol Grip Selector Lever Magazine Slipring Rear Sling Swivel Stock
  78. 78. CLASSIFICATION OF FIREARMS 1. According to gun barrel construction a. smooth-bore firearms – have no riflings inside the gun barrel. b. rifled-bore firearms – firearms that have riflings inside their gun barrel.
  79. 79. 2. According to the caliber of the projectiles propelled a. artillery – can propel projectiles more than one inch in diameter. b. small arms - can propel projectiles less than one inch in diameter. E.g. machine gun, shoulder arms and hand arms.
  80. 80. 3. According to mechanical construction a. single shot firearms b. repeating arms c. bolt action type d. automatic loading type e. slide action type (trombone) f. lever type (break-type)
  81. 81. 4. According to use a. military firearms b. pocket and home defense firearm c. target and outdoor men’s firearms 5. Unusual or miscellaneous type – those types of firearms that are unique in mechanism and construction. a. paltik pistols b. paltik revolvers c. paltik rifles d. paltik shotgun
  82. 82. Break for 30 minutes!!!
  83. 83. Ammunition Chapter 4
  84. 84. LEGAL DEFINITION Found in Chapter VII, Section 290 of National Internal Revenue Code as well as in Section 877 of Revised Administrative Code - It refers to a loaded shell for rifles, muskets, carbines, shotguns, revolvers, and pistols from which a ball, bullet, shot, shell or other missiles may be fired by means of gunpowder or other explosives.
  85. 85. TECHNICAL DEFINITION It refers to a group of cartridges or to a single unit cartridge – meaning a complete unfired unit consisting of a bullet, cartridge case, gunpowder and primer. The term may also refer to a “single round”. Cartridge – is a complete round of ammunition for a firearm. The term cartridge and ammunition can be used interchangeably.
  86. 86. ORIGIN The cartridge evolved about the turn of the 16th century. In 1635, the first cartridge was invented by King Gustavus Adolphus of Sweden. He was credited with this invention. These were simple packages, which he furnished to his troops during the 30 years of war. The package was torn, and the content was poured down inside the barrel. Most shooters during those days had to carry two powder horns, the first is for the powder to be poured in the barrel, and the second is for the fine grains powder for priming charge. The invention of paper cartridge eliminated the package of the use of horn in carrying the powder mixture in bottles or tube.
  87. 87. The term cartridge evolved about the turn of 6th century. The earliest small arms ammunition or cartridge consisted of a pre-measured charge of powder wrapped in paper. The term cartridge is derived from the word “charta”, the Latin word for paper. Later on, it came through the French word “cartouche”, meaning a roll of paper, which indicates that the original cartridge were not the brass gliding metal tipped units which we are familiar with today. The paper cartridge remained standard, for muzzle loading firearms though the middle of the 19th century. The paper cartridge was designed for combustible cartridge. It was employed in muzzle-loading firearms, revolving chamber firearms, and in several breech-loading firearms. The casing and enclosing the gunpowder was made from nitrated paper, collodion, cloth, animal intestine or some other materials which would not leave a residue in the chamber of the gun barrel after firing.
  89. 89. ACCORDING TO LOCATION OF PRIMER 1. Needle-fire cartridge – the primer is placed in the base of the bullet. A long sharp firing pin is pierced the paper or foil case to reach the primer. 2. Tit-fire cartridge – a copper case nipple containing the protruding cup, through which a hole rear the breech block, to the struck and detonated by the falling hammer.
  90. 90. 3. Tail-fire cartridge – the opening of the rifle for loading is compressed by spring, once the rifle has been loaded and the breech is closed, operation of the trigger to crush against the underside of the block, and detonate a flat percussion tail from the rear of the cartridge. 4. Pin-fire Cartridge – the first cartridge of self-exploding type developed by Monsieur Le Facheux of Paris, around 1836. The primer was placed on the sidewall of a copper case and a brass pin was installed in the opposite side of the case, the intended pin rested on the primer then the hammer fall on the side of the case, driving the pin into the primer.
  91. 91. 5. Rim-fire Cartridge – developed by Louis Nicolas Auguste Flobert of France, around 1845, the priming mixture is contained or located in the cavity inside and around the rim of the cartridge which is a very sensitive area. This cartridge is usually applied to caliber .22 firearms. 6. Ring-fire cartridge – it is a type of cartridge used on the sabotage case. This is a special type of cartridge wherein the priming mixture is placed in a circular hollow ring about 1/3 of the base of the cartridge.
  92. 92. 7. Volcanic cartridge – a system made by Robin and Laurence around 1854. The cartridge was a mini ball with a base cavity filled with propellant. A paper disc holding a fulminate pellet is closed at the back of the base, this type of cartridge is similar to needle-fire but the firing pin can easily damaged. 8. Center-fire Cartridge – in 1858, the Moors cartridge marked the development of this cartridge. The primer cap is forced into the middle portion of the head of cartridge case.
  93. 93. ACCORDING TO TYPE OF FIREARM USED 1. Revolver cartridge – it has a rimmed base, which allows the cylinder where the chamber is located to clamp its rim. 2. Pistol cartridge – extracting grooves are designed to allow easier packaging of the rounds in the magazine.
  94. 94. 3. Assault rifle cartridge – longer than a hand weapon and generally bottle necked for larger powder capacity and increased powder. 4. Shotgun cartridge – the case is generally made up of plastic or paper designed to fire several projectiles spreading out to create a come of fire. 5. Caseless cartridge – the powder is the casing itself, of the projectiles. It requires varnishing to protect it from moisture and moderate shocks. There are few residues left after the gunpowder had exploded. The cross section is generally fragile to cause for fragmentation.
  95. 95. ACCORDING TO TYPE OF CALIBER The caliber of a gun is the diameter of its bore, measure in fraction of an inch between two opposite lands for barrel with even lands. The caliber of a firearm designated only as an approximation of the bore diameter, and is usually closer to the groove diameter. The different systems of measuring caliber of firearm are Metric or European (millimeter) and English or American (inches) systems of measurement. In converting millimeters to inches – multiple the millimeters by .03937 or divide by 25.4 while converting inches to millimeters – multiple by 25.4 or divide by .03937.
  96. 96. SHOTGUN SHELL It is the cartridge for shotgun. It is also called a “shell”, and its body may be made up of metal or plastic or paper with a metal head. The length of a shot shell is normally given in inches and is based on the length of the spent hull.
  97. 97. PARTS OF SHOTGUN SHELL 1. Shot cup – it is a plastic cup that holds shot in pattern as it leaves from the muzzle of the firearm. 2. Tube or case – prior to 1960, a paper tube were used, with mouth closed by rolled crimps or with plastic body or hull with mouth closed by die crimp, eliminating need for overshot wad. 3. Primer – it is the very sensitive part of the cartridge located in the bottom portion of the case which ignites the powder charge. 4. Propellant – a chemical compound used in firearms that burns upon ignition. The gases produced by this rapid combustion propel the pellet down the bore of the firearm.
  98. 98. 5. Crimp – portion of the cartridge that is bent inward to hold the shots in place. 6. Wads – it helps to contain the shot, seal off the shot payload from the ignition gases to prevent deformation and protects the barrel from lead building up. The four types of wads are base wad, under powder, over powder and filler. 7. Shot/pellet – small spherical projectiles for shotgun.
  99. 99. KINDS OF SHOT/PELLET 1. Buckshot (BS) – consist of a number of lead balls that spread out as they travel. These pellets are not very effective (in 00 buckshot, each one is .33 inch in diameter), but collectively they result in large and destructive wounds. At longer distance, however the shot spreads and fewer pellets hit the target.
  100. 100. 2. Slug (SL) – instead of a group of lead balls, the shell contains a single huge bullet with angled grooves cut into its side to spin it, as it travels down the smooth bore of a shotgun. The penetration of a slug is better than shot, but the wound channel is not as wide as the shot. 3. Tungsten-Iron shot – it is formed either powdered tungsten and powdered iron, they are blended together and pressed into pellet, then sintered or bonded together by heating process. The shot is coated with a rust inhibitor and it is harder than both lead and steel.
  101. 101. 4. Flechette Shot (FS) – a cluster of sturdy steel needles, replaced the shot of the standard shotgun shell. These flechettes have tiny fins at their base to stabilize them in flight. Air resistance is greatly improved over shot, than in armor piercing capability. 5. Armor-piercing Bullet (APB) – the discarding sabot slug processes an aerodynamic shape that keeps it stable flight even though it does not spin. It is smaller in diameter than a standard slug, and surrounded within the shell by a tow- piece plastic sabot. After exiting the barrel, the sabot splits in half and falls away because of air resistance.
  102. 102. 6. Steel Shot – it is made by cutting soft steel wire into short lengths, which are formed into shot. The shot is then annealed and coated with a rust inhibitor. Wads for steel shot ammunition, are molded from high density polyethylene. It has thick sidewalls to prevent the pellets from contracting the shotgun bore surface. High velocity steel loads have a cushion to reduce recoil. 7. Tungsten-Iron and Steel – this shell has a layer of steel over a layer of tungsten-Iron. It gives a dense combined pattern at longer ranges. It can be used in any shotgun recommended for steel shot.
  104. 104. Bullet Chapter 5
  105. 105. DEFINITION It is a metallic or nonmetallic, cylindrical projectile propelled from a firearm by means of an expansive force of gases coming from burning gunpowder. The term may also include projectiles propelled from shotguns, although strictly speaking, these projectiles designed for shotgun are called “shots” or “pellet”.
  106. 106. ORIGIN The term bullet originated from the French word “boulette”, means “small ball”. The projectile of most small arms ammunition primarily means a projectile from a rifled arm which is cylindrical or cylindro-conoidal in shape as opposed to round projectiles which are commonly called either a ball or shot.
  108. 108. ACCORDING TO USE 1. Ball bullets – those have soft cores inside a jacket and are used against personnel only. 2. Armor piercing bullet – those that have steel cores and are fired against vehicles and other armored targets in general.
  109. 109. 3. Tracer bullet – those that contain compound at its base which is set on fire when the bullet is projected. The flash of smoke from this burning permits the flight of the bullet to be seen, especially at night time. This type of bullet is primarily used for target acquisition. 4. Incendiary bullet – those that contain mixture, such as phosphorous or other material, that can be set on fire by impact. They are used against the targets that will readily burn such as aircrafts or gasoline depots. 5. Explosive (fragmentary) bullet – those types of bullets that contain a highly charged explosive. Because of their small size, it is difficult to make a fuse that will work reliably in small arms ammunitions.
  110. 110. ACCORDING TO MECHANICAL CONSTRUCTION 1. Lead bullets – those which are made of lead or alloys of this metallic lead, tin and antimony which are slightly harder than pure lead. 2. Jacketed bullets – those with a core of lead covered with a jacket of harder material such as: gilding metal, a copper alloy of approximately 90% copper and 10% zinc. 3. Synthetic bullets – those made of plastic/plasticize and other composition or those made of sand polymer mixed. Such bullets were designed for special purposes.
  111. 111. BULLET DESIGNED FOR HANDGUNS 1. Full metal jacket – lead core is enclosed by a strong metal jacket on this non-expanding, deep-penetrating, general purpose bullet which provides smooth, reliable feeding in all types of semi-automatic handguns.
  112. 112. 2. Jacketed hollow point – the exposed lead at the tip of the jacketed hollow point, rapidly initiates uniform controlled expansion that progresses to the depth of the hollow point cavity. It has excellent accuracy and bullet integrity.
  113. 113. 3. Semi-jacketed hollow point – it has more exposed lead at the tips, which expand less than a jacketed hollow point bullet.
  114. 114. 4. Full metal cone – the lead core of this bullet is enclosed in a light copper jacket, which has a cone shape and a flat point. The result is less expansion than JHP bullet, but more than an FMJ, and deeper penetration than SP bullet.
  115. 115. 5. Lead wadcutter – the full wadcutter profile of this solid lead cuts clean signature in paper targets for precise scoring.
  116. 116. 6. Lead semi-wadcutter – solid lead bullet with semi-pointed nose. Formed by swaging process with sharp shoulder for clean hole punching in paper targets. It is good choice for general purpose shooting.
  117. 117. 6. Soft point – Exposed lead soft point initiates reliable expansion, provides deeper penetration than hollow point bullets. Precisely engineered copper jacket and the swaged lead core provide the necessary concentricity and balance required for top-level accuracy.
  118. 118. 7. Lead round nose – solid lead bullet with rounded ogive for downrange accuracy.
  119. 119. BULLET DESIGNED FOR RIFLES 1. Full metal jacket – the lead core of this bullet is enclosed in a heavy copper jacket, which results in little or no expansion and deep penetration. 2. Full metal jacket boat tail – same with full metal jacket with boat tail heel to further reduce drag to improve downrange velocity.
  120. 120. 3. Hollow point boat tail – extremely accurate hollow point bullet with pointed aerodynamic design. Boat tail heel to further reduce drag to improve downrange velocity. Precision balance and exceptional concentricity greatly increase bullet stability to assure superb accuracy. 4. Soft point – Exposed lead tip on this bullet and broader point diameter provides rapid, controlled expansion at somewhat lower velocities. Broad wound channel results from expansion up to 200% of original bullet diameter.
  121. 121. DIFFERENT TYPES OF BULLET 1. Hard ball – a copper sheath, the jacket, over a core of lead. It is the standard projectile type, expanding very little, but giving good penetration. 2. Depleted Uranium – it is ideal for use in armor penetrators because it has an exceptional performance against armored targets.
  122. 122. 3. Semi-wadcutter – a bullet with a flat nose in front of a sharp wad-cutter style shoulder. This type of bullet, when the shoulder is too sharp, this will have a clear cut hole on the target. 4. Silver tip – Winchester trademarks for certain bullet designs. The jacket will disintegrate into small pieces that will precisely cause hemorrhage. 5. Fragmentation or explosive bullet – splits to fragment when hitting soft tissues, creating big wounds but tends to retain its form when penetrating armor.
  123. 123. 6. Spitzer – a type of bullet having a sharply pointed nose. This type of bullet when it hit the hard object likes bones inside the body, it changes it bullet track hence, and the tendency is that, the bullet traveled sideways which will create a wider size of exit wound. 7. Dumdum bullet – outlawed for use in war, any bullet with the core exposed. 8. Soft point or mushroom bullet – expands as it strikes an object and produces much more serious shock and has correspondingly greater stopping power.
  124. 124. 9. Hollow point bullet – a bullet with a cavity in the nose designed to increase the expansion when it hits the target. 10. Steel jacketed bullet – composed of a soft steel jacket, often clad or plated with gliding metal to prevent rusting and reduce frictional resistance in the bore. 11. X-bullet – is a solid copper projectile, heat treated for extra toughness with no separate jacket and no lead core. It designed by Randy Brooks.
  125. 125. 12. Pointed bullet – more effective than round ball because there are fewer surfaces presented to the air and thus the speed of the bullet is less retarded so quickly. 13. Boat tail – a bullet with a base tapering to smaller diameter. 14. Gas check – a small metal cup fitted to the base of a lead bullet, to protect it from the hot gases created by the burning gunpowder. 15. Glaser safety slug – is high performance ammunition that gives superior penetration in solid targets, while delivering maximum stopping power, with minimum danger from over penetration and ricochet.
  126. 126. SHAPES OF BULLET
  127. 127. PARTS OF BULLET 1. Base – the portion of the bullet that receives the thrust and heat from the burning gunpowder. 2. Bearing surface – the area of the bullet that contacts the barrel riffling. A tight fit is required to prevent chamber pressure leaks and to provide good contact with the rifling grooves. 3. Core – the bulk of the mass in the bullet. 4. Head height – length of the bullet from the shoulder to the tip. 5. Heel – the location of the bullet where the heel ends and the bearing surface begins.
  128. 128. 6. Jacket – is material that covers some or the entire core. 7. Meplat – is the diameter of the flat or blunt end of the nose of a bullet. 8. Ogive – is the radius of curve between the bearing surface and the point usually stated with respect to the caliber. 9. Point – the most forward point of the ogive. 10. Shoulder – is the place on the bullet where the parallel sides’ end and the ogive begin.
  129. 129. PARTS OF BULLET
  130. 130. Cartridge Case Chapter 6
  131. 131. DEFINITION It refers to a tubular metallic or nonmetallic container which holds together the bullet, gunpowder and primer. Another term used is shell or casing. The cartridge is the portion of cartridge that is automatically ejected from automatic firearm during firing and these remains in the crime scene. Drawing - refers to the machine operation of making cartridge cases.
  132. 132. FUNCTIONS OF CARTRIDGE CASE • It holds the bullet, gunpowder and primer assembled into one unit. • It serves as a waterproof container of the gunpowder and gas seal at the breech end of the barrel.
  133. 133. PARTS OF CARTRIDGE CASE a. Rim – limits the forward travel of cartridge into their chambers and thus also limits the clearance between the heads and supporting. b. Primer pocket – holds the primer securely in the central position, provides a means to prevent the escape of gas to the rear of the cartridge and a solid support of primer anvils, without which the latter could not be fired. c. Vents/flash hole – the hole in the web which serves as opening or canal that connects the priming mixture with the gunpowder.
  134. 134. d. Head/body – constitutes the cork that plug the breech of the barrel against the escape of gas. e. Neck – it is occupied by the bullet. f. Cannelure – the serrated grooves that are sometimes found rolled into the neck and body of the case at the location of the bases of the bullet; they prevent the bullet from being pushed back or loosened. g. Shoulder – portion that supports the neck. h. Base – bottom portion of the case which holds the primer and shell head. i. Extracting groove – circular groove near the base of the case or shell designed for the automatic withdrawal of the case after firing. j. Crimp – this is the part of the mouth of a case that is turned in upon the bullet.
  135. 135. THREE TYPES OF CRIMP a. Roll Crimp – the cartridge case neck was rolled into the bullet material of groove in the bullet, to secure it, and ensure even from tension of the cartridge case. It need to be trimmed to a uniform length and are primarily used on cartridges that have headspace on the rim or cartridge case shoulder.
  136. 136. b. Taper Crimp – it is used primarily in the cartridge with headspace on the cartridge case mouth, with lead bullets. While it can be used to secure jacketed bullets, this can led to bullet distortion. With a taper crimp, the mouth of the cartridge case run into a die, with a tapered opening that squeeze the diameter of the neck down, enough to grip the bullet securely, but still leaves enough space for headspace on the chamber.
  137. 137. c. Stab/Rim Crimp – it is used only on jacketed ammunition, which consist either several impressed dimples or a groove, pressed into the cartridge case mouth by a collet. The crimp can either enter a groove on the bullet or can just press into the bullet body, which distorts the bullet. It is primarily used on military or commercial heavy caliber hunting ammunition, where rough handling may be encountered.
  138. 138. CLASSIFICATION ACCORDING TO CASE SHAPE • Straight • Bottle neck • Tapered (obsolete)
  139. 139. CLASSIFICATION ACCORDING TO CASE RIM a. Rimmed – the diameter of the base of the cartridge is very much bigger than the diameter of the body of the cartridge. (44 magnum, 303 British, 38 special, 357 magnum, etc.) b. Rimless – the diameter of the rim is equal with the diameter of the body of the cartridge case. (.30-06, .270, .308 etc) c. Semi-rimmed – the diameter of the rim is slightly greater than the diameter of the body of the cartridge case. (.25 ACP, .38 Super) d. Belted – has a protruding metal around the body of the cartridge case. (.7mm Remington Magnum, .300 Winchester, .375 H&H Magnum) e. Rebated – the diameter of the rim is smaller than the body of the cartridge case. (.41 AE, 50 Beowulf)
  140. 140. Primers Chapter 7
  141. 141. DEFINITION It is a small, self-contained metallic ignition cap at the center or at the cavity of a cartridge case that when struck by the firing pin combusts and sends sparks through the flash hole of the cases and ignites the powder charge. (percussion)
  142. 142. ORIGIN Alexander John Forsyth (1847) is credited with being the first to conceive the idea by using detonating compounds for igniting powder charge in small arms by percussion. A Scottish Presbyterian clergyman, he invented the percussion ignition. While hunting wild duck he was dissatisfied with his flintlock fowling-piece due to its hang-fire; by the time the bullet was discharged the duck had time to dive before the shot reached them. His first successful priming mixture was composed of Potassium Chlorate, charcoal and sulfur in powder form.
  143. 143. PARTS OF PRIMER a. Primer cup – the container of priming mixture. b. Priming mixture – a highly sensitive chemical mixture contained in the primer cup. c. Anvil – portion of the primer against which the priming mixture is crushed by blow of firing pin. d. Disc – a piece of small paper or disk of tin foil which is pressed to the priming mixture.
  144. 144. CLASSES OF PRIMERS a. Corrosive Primers (potassium chlorate) - draws moisture from the air when ignited, and this moisture speeds the rusting of gun barrel. b. Non-corrosive Primers - potassium chlorate was replaced by barium nitrates. It was invented by Swiss army and inventor Karl Ziegler.
  145. 145. TWO KINDS OF PRIMER a. Berdan Primer The primer cup contains only the priming mixture and the anvil is part of the cartridge case. It contains two of more vents and requires special tools to remove them easily and not generally reloaded. It was invented by Hiram Berdan in March 20, 1866. b. Boxer Primer The anvil is an integral part of the primer assembly and contains only one flash hole. This kind of primer is commonly used in present time for centerfire cartridges. It was invented by American Inventor Col. Edward M. Boxer on June 29, 1869.
  146. 146. Gunpowder Chapter 8
  147. 147. DEFINITION It refers to the chemical substances of various compositions, particles sizes, shapes and colors, which when ignited by the primer flash, is converted to gas under high pressure and propels the bullet or shot charge through the barrel to the target. The term gunpowder is synonymous to the term propellant, cordite and powder charge that can be used interchangeably. About the weight of the powder charge in a cartridge, the weight of the gunpowder is expressed in grains in English System of while in Metric System, the weight of gunpowder is expressed in grams.
  148. 148. CLASSIFICATION AND COMPOSITION 1. Black powder – the oldest form of propellant and when fired, produces large volume of grayish smoke and leaves considerable residue in the barrel. The person credited for the invention of such is Roger Bacon in 1248. It is composed of potassium nitrates (75%), sulfur (10%) and charcoal (15%) 2. Smokeless powder – the powerful propellant used today and is made up of nitrocellulose. The term smokeless is a misnomer for they are neither powder nor smokeless. The powder is said to be smokeless only because it does not give off huge cloud of white smoke like black powder.
  149. 149. In 1886, Paul Vieille, invented the smokeless gunpowder with nitrocellulose, a single base propellant called Poudre D, made from gelatinize guncotton mixed with ether and alcohol. It was cut into flakes of the desired size. In 1887, Alfred E. Nobel of Great Britain developed smokeless gunpowder called Ballistite, a double base propellant. In 1890, Sir Frederick Abel and James Dewar obtained a patent on a modified form of smokeless gunpowder known as cordite.
  150. 150. KINDS OF SMOKELESS POWDER 1. Single base/nitrocellulose – contains only pure nitroglycerin with nitrocellulose. 2. Double base – composed of nitrocellulose and nitroglycerin as major ingredients; accompanied by one or more minor ingredients such as centralite, vaseline phthalate and inorganic salts. 3. Triple base – the three principal ingredients used such as nitrocellulose, nitroglycerin and nitro-guandine. 4. High Ignition Temperature Propellant – the main constituent of high explosives from RDX group.
  151. 151. Arms Manufacturing Chapter 9
  152. 152. INTRODUCTION The barrel, which is one of the most important parts of firearm, is a cylindrical in shape with projecting length. It is made of a carefully selected solid piece of metal, fitted for its chemical and metallurgical structure which has the capability to withstand explosion and tremendous pressure coming from the expansion of heated gas coming from burning gunpowder. This provides a high quality product after the various machine operations, until it becomes a finish product and consequently as a real firearm. Making of Rifled Barrels • Drilling Stage – a solid piece of cylindrical metal is drilled by special deep-hole drill; through the center of which lubricating oil is forced under pressure.
  153. 153. • Reaming Stage – removes scars and scratches left by the drilling operation. The reamer used is slightly greater in diameter than that of the drill therefore removes excess metal from the entire surface of the bore. There are three types of reamers used in reaming the bore of barrel; roughing, finishing and burnishing. • Rifling stage – the creation of the land and grooves inside the bore to improve projection of the bullet during firing. • Cut rifling technique – the oldest method of making riflings invented in Nuremberg at around 1942. A hook cutter is pulled through the bore numerous times and indexed after every stroke to produce the riflings. • Broaching system – broaching cutter that cuts a longitudinal spiral grooves inside the barrel. It produces the desired number of lands and grooves in a single stroke. • Button system – it produces the desired number of lands and grooves simultaneously but in a different manner. It does not cut longitudinal spiral grooves inside but it produces the same by depressing a portion of the internal surface of the bore thus creating the grooves. • Lapping stage – this is the polishing operation wherein a lead plug is used in removing many of the larger imperfections due to the cutting of forming operation.
  154. 154. COMPOSITION OF RIFLINGS • Lands – refers to the raised metal between grooves. • Grooves – depressed portion of the gun barrel. • Width of lands and grooves • Depth of grooves • Pitch of riflings – the number of inches traveled by the bullet to make one complete run. • Twist of riflings – the direction of twist whether left or right.
  155. 155. MAKING OF BREECHFACE AND FIRING PIN The breechface of all firearms are machine cut in the first place, and in the higher grade weapons are finished off by hand filing and grinding. Similarly, the firing pin of all weapons are cut and shaped, receiving different degrees of fire finishing according to the grade of weapon in which they are to be used. The breechface is the portion of the firearm against which the cartridge case and the primer are forced backwards upon firing while the firing pin is the part of the firearm which strikes the primer of the cartridge.
  156. 156. FACTORS THAT AFFECTS BREECHFACE IMPRESSION 1.Powder charge of the cartridge 2.Softness of the primer cup and the surrounding brass 3.Sharpness of the striations on the breechblock 4.Presence of oil, grease or foreign matters on the block 5.Factory stampings on the cartridge head
  157. 157. Firearms ID Chapter 10
  158. 158. PRINCIPLE IN FIREARM IDENTIFICATION • It is a refined toolmarks identification. • The natural wear and tear of the tools is involved. • When the soft surface come in contact with the hard surface is left with the impressions or scratches from any irregularities on the hard surface. • Principle of individuality, i.e. no two things are absolutely identical.
  159. 159. MARKS FOUND ON FIRED BULLETS a. Lands marks – depressed portion caused by lands that can be found in the cylindrical surface of the fired bullet. b. Groove marks – raised or the elevated portions caused by the grooves that can be found in the cylindrical surface of the fired bullet. c. Skid marks – found on the anterior portion of the fired bullets and caused by the forward movement of bullet from the chamber before it initially rotates due to the rifling inside the barrel. d. Stripping marks – found on bullet fired though loose fit barrels wherein the riflings are already worn out.
  160. 160. MARKS FOUND ON FIRED SHELLS 1. Striated action marks are common to cartridge cases that have passed through the action of an auto loading or repeating firearm. Striated action marks can be produced on cartridge cases by contact with a number of different areas within the firearm. 2. Impressed action marks, with a few exceptions, are produced when a cartridge case is fired in a firearm. The two most common impressed action marks are firing pin impressions and breech marks.
  161. 161. 1. Chamber mark – found in the body of the shell due to the irregular makings in the chamber. 2. Firing pin mark – found in the primer cup or the rim of the cartridge case. 3. Shearing marks – secondary firing pin mark found near the firing pin mark. 4. Extractor mark – found in extracting groove in automatic firearms.
  162. 162. 5. Ejector marks – located in the rim in automatic firearms. 6. Pivotal mark – marks found on the shell caused by turning of the cartridge. 7. Magazine lip markings – these are markings found at the low points of the rim of the base of the shell and these are caused by the magazine lips during the loading of the cartridge into the magazine for firing. 8. Breechface marks – found on the base of cartridge case as a result of the rearward movement of cartridge case during firing.
  163. 163. Characteristics of Firearms
  164. 164. CLASS CHARACTERISTICS Those are characteristics that are determinable even prior to the manufacture of firearms. These characteristics are factory specifications and within the control of man. These serve as basis for identifying certain group or class of firearms. These are: a.Bore diameter/caliber – the diameter which the bore was reamed. It is the distance measured between two opposite lands inside the bore. Caliber is of English origin while the millimeter (mm) is a European origin.
  165. 165. b. Number of lands and grooves – the number of lands is always equal with the number of grooves. c. Width of lands – it is the remainder of the circumference after subtracting the groove width. d. Direction of twist – it cause the bullet to rotate as it passes through the barrel for the bullet to have gyroscopic motion during its flight. e. Depth of groove – measured on the radius of the bore as seen in cross section. It is equal to the height of the side of a lands. f. Pitch of riflings – it is the twist of lands and grooves. It also refers to the distance advanced by the riflings in a complete run.
  166. 166. TYPE OF RIFLINGS a. Steyr Type – 4RGL b. Smith and Wesson Type – 5RGL c. Browning Type – 6RG2X d. Colt Type – 6LG2X e. Webley Type – 7RG3X f. Army Type – 4RG3X
  167. 167. INDIVIDUAL CHARACTERISTICS Those are characteristics peculiar and not found in all other firearms. These serve as the basis for identification of particular firearm and identifiable only after the manufacture of the firearm. These characteristics is beyond the control of the man and which have random distribution inside the gun. Their existence in a firearm is brought about by the tools used in their manufacture in their normal operation resulting to the wear and tear, abuses, mutilations, corrosions, erosions and other fortuitous causes. These characteristics are generally found in the interior surface of the gun barrel and breechface.
  168. 168. 7 PROBLEMS OF FIREARM IDENTIFICATION 1. Given a bullet; to determine the caliber and type firearms used. 2. Given a cartridge case; to determine the caliber, name of manufacturer and the type of fire arm used. 3. Given a bullet and firearm, to determine whether or not the bullet was fired from suspected firearm submitted. 4. Given a fired cartridge case and a suspected firearm, to determine whether or not the cartridge case was fired from the suspected firearm submitted. 5. Given two or more bullets, to determine whether or not the bullets were fired from only one weapon. 6. Given two or more fired cartridge cases, to determine whether or not the cartridge cases were fired from only one weapon. 7. Given a firearm, to determine whether it is serviceable or not.
  169. 169. BULLET HOLES Glass – a super cooled liquid that possess high viscosity and rigidity. Two kinds of Crack a. Radial Crack – primary fracture resembles the spokes of a wheel radiating outward from the point of impact. b. Concentric Crack – secondary fracture forming in an approximately circular pattern around the point of impact.
  170. 170. 3 R RULE A principle used for radial crack which states that stress lines on radial crack will be at right angle to the rear side of the glass. RFC RULE A principle used for concentric crack which states that stress lines on a concentric crack will be at right angle to the front side, that is the side from which the impact or blow came.
  171. 171. 5 TEST FOR GLASS 1. Spectrographic test – used to determine the elements of the glass. 2. X-ray diffraction test – used to determine the type of glass pattern. 3. Physical properties examination – used to determine the density of the glass by flotation method and refractive index by immersion method. 4. Study of polish mark – a test for fine glass wares and optical glass. 5. UV light examination – used to determine the differences in physical and chemical composition of glass specimen.
  172. 172. Crime Scene Processing Chapter 11
  173. 173. INTRODUCTION The search of the scene for ballistic exhibits is one of the most important phases of crime investigation. Crime of violence, especially wherein firearms had been used, sometimes involves struggle, a break, and the element of unpredictability. In homicide, murder and armed robberies, the criminal is in contact with the physical surroundings in a forceful manner. Traces of the commission of the crime may be left in the form of fired bullets, fired shells, and suspected firearm. These firearm evidences, or ballistic exhibits as they are sometimes called, might be of value in tracing the perpetrator or perpetrators of the crime so committed. Together with these, there might be other traces that may link him to the crime committed. A well-planned and organized method of investigation should guide the basic search. The search to be followed by the investigator should be thorough and complete, and no details of the surrounding area should be over-looked by the investigator. There might be some types of evidence, which might be of the highest significance to firearms investigation.
  175. 175. 1. STRIP METHOD It involves the demarcation of a series of lanes down which one or more persons proceed. Upon reaching the starting point, the searchers proceed down their respective lane, reverse the direction, and continue in this fashion until the scene has been thoroughly examined.
  176. 176. 2. DOUBLE STRIP METHOD It is also known as grid method. The researcher perform first the strip method and after which turns and proceed back along new lanes but parallel to the first movement. This method offers the advantage of being more methodological and through; examined from two different viewpoints, the area is more likely to yield evidence that might have been overlooked.
  177. 177. 3.SPIRAL METHOD It is usually employed in outdoor scenes and is normally executed by a single person. It involves the searcher’s walking in slightly ever-decreasing, less-than-concentric circles form the outermost boundary determination towards a central point and vice-versa.
  178. 178. 4. ZONE METHOD It requires that area should be divided into four quadrants, each of which is then examined using of the methods previously described. Where the area to be searched is particularly large, a variation of the zone method would be subdivide the small quadrants into a smaller quadrants.
  179. 179. 5. PIE METHOD It is also referred to wheel method. The searchers gather at the center and proceed outward along radii or spoke. The principal drawback of this method is that the distance between the researchers increases as they depart from the center.
  180. 180. PHYSICAL EVIDENCE Anything that has material existence and which may be used to establish the nature of the offense or the identity of the perpetrator and which may be presented to the court for its evaluation or appreciation. Properly prepared and presented physical evidences may serve the same purpose as taking the court to the scene of the crime and reconstructing the events which led to the commission of crime. A thorough understanding of physical evidence, its protection, preservation and examination is important.
  181. 181. Evidence – is the means sanction by law, of ascertaining in a judicial procedure the truth respecting a matter of fact. “Evidence speaks by itself”
  182. 182. RECOGNITION OF EVIDENCE At the crime scene, the prober must exercise keen observation and extreme care in his search for these physical evidences or ballistics exhibits like fired bullets, fired shells, firearm/s and allied items or objects. The success of the case will depend heavily on how the prober conducts himself in handling those ballistics exhibits. He has to do his job well at “proper time” and “proper place”. Proper time refers to when he is right there in the scene and proper place refers to the right there at the scene. It is important therefore that the investigator be familiar with the modern techniques in the proper recognition, collection, marking, preservation and transmittal of these physical evidences.
  183. 183. COLLECTION OF PHYSICAL EVIDENCE 1. Collect all articles, which are, or may be in some future date, be of value as evidence. 2. Evidence which may tend to show or indicate or not a crime was committed or may connect some particular person with the crime or crime scene such as fatal gun, fired bullet, fired shell, metal fragment, broken glass, holster, magazine, cartridge, gloves and masks. 3. Designate one officer to collect all evidence to centralized the collection. 4. Don’t MAC the evidence. M – mutilate the evidence A – alter the very nature of evidence C – contaminate the evidence 5. Sketch and photograph the crime scene.
  184. 184. COLLECTION OF PHYSICAL EVIDENCE 6. Photograph the articles before removing them. 7. In cases if the fired bullets lodge in an object, extreme care must be exercise in removing such. 8. If the bullet has broken into fragments, secure fragments as many as possible. 9. When firearm/s is/are found in the crime scene, note the following: a. type of FA b. Caliber c. Serial number d. Condition of FA e. Position of FA relative to the body at the scene f. Other details of FA
  185. 185. COLLECTION OF PHYSICAL EVIDENCE 10. When bullet/s is/are found at the scene, the following shall be noted: a. Type b. Caliber c. Shape d. Metal or bullet fragments e. Place and date of recovery 11. When shell/s is/are found in the crime scene, note the following: a. Number of shells b. Caliber c. Trademark or brand d. Place and date of recovery
  186. 186. COMMON MARKS FOUND ON HEADSTAMP • ACP – Arms Corporation of the Philippines • Automatic Colt Pistol • BAR – Browning Automatic Rifle • RA or REM – Remington Arms Company • RPA – Republic of the Philippines Arsenal • LC – Lake City Arsenal • FCC – Federal Cartridge Corporation • EAA – European American Arms • U or UT – Utah Ordnance Company • WCC – Western Cartridge Corporation • WRA – Winchester Repackaging Corporation • Luger
  187. 187. PROPER COLLECTION OF FIREARMS IN THE CRIME SCENE By using a handkerchief, string or wire inserted through the trigger guard of the firearm. Be sure that in picking up the suspected firearm the muzzle end of the barrel is not pointed to anyone in the vicinity. More so, if it is revolver and this revolver is in full-cocked position, there is always the danger of a little amount of jarring when picking up as the gun might fire, causing additional shooting or accident. After picking up the revolver, a piece of crumpled paper or carton maybe place just in front of the trigger after which the trigger should be checked. This is done to prevent accidental or unnecessary firing.
  188. 188. MARKING OF PHYSICAL EVIDENCE 1. Physical evidences should be properly marked or labeled for further identification as they are collected and to complete the chain of possession or custody of the ballistics exhibits. 2. Mark at the time that evidence is removed from its original position. However, do not mark or move until photograph has been taken. 3. Keep a complete note on the marks placing it on every single or individual object recovered in the crime scene. 4. Use distinctive initials of the recovering officer. Never use “X”. 5. Record the mark used, and the position of the marks present on the object. 6. Record serial number or other distinct marks present on the object. 7. Always mark the container in which the object is placed even if the object is already marked. (Tagging)
  189. 189. MARKING FIRED BULLETS Fired bullet should be marked by the recovering officer with his initial together with the corresponding date of recovery in the OGIVE or NOSE or its ANTERIOR PORTION with stylus or any pointed instrument. But is cases that the fired bullet is badly damaged or disfigured the marking could be place on the base but never in the bearing surface or cylindrical surface of the fired bullet.
  190. 190. MARKING FIRED SHELLS Same in marking of fired bullets but the marking should be place either INSIDE, NEAR THE OPEN MOUTH, OUTSIDE, NEAR THE OPEN MOUTH OR NEAR THE BODY OF THE SHELL, but never place your marks on the base of fired shells.
  191. 191. MARKING A SUSPECTED FIREARMS Same in marking of fired bullets and fired shell but the marking should be place on all the three main and inseparable part of the firearm. In addition, a tag may be made indicating the type of firearm, make or model, caliber, serial number, date of recovery, name of suspect or victim (if known) and other features of value.
  192. 192. PRESERVATION OF PHYSICAL EVIDENCES Physical evidence should be preserve for future identification and presentation during the trial of the case. The container of ballistics exhibits should be properly labeled by the prober and put down all the steps he has taken in preserving all these physical evidences for future use. Preserving the evidentiary value of physical evidence determine the acceptability and reliability of evidence in court. TRANSMITTAL OF PHYSICAL EVIDENCE After the collection and marking of physical evidences, the prober will transmit the evidences to their respective departments and submit the same to the duty desk officer or designated receiving officer-in-charge.