Specialty Binder

1. Objectives, Introduction, and Firearm Accuracy 2. Firearm Accuracy 3. Increasing the Force of the Bullet 4. Improving the Rate of Firing and Firing Reliability 5. Handguns 6. Rifles 7. Shotguns 8. Ammunition 9. Ballistics 10. Collection and Preservation of Firearm Evidence (1 of 6) 11. Laboratory Examination of Firearm Evidence

 Gain an understanding of…..  -using rifling marks on a bullet for identification of manufacturer of gun fired  -difference between rifles, shotguns, revolvers, semi-auto pistols  -compentents of ammunition  -The integrated ballistic identification system  - ways to restore obliterated firearm serial numbers

 Recovery of firearms or related items is very important to the investigation of crimes involving firearms  Firearm technology focuses on 4 major problems Projectile accuracy Increasing projectile force Increasing firing rate Improving reliability of firing mechanism

 Lengthening of barrels can improve firearm accuracy  Rifling: spiral grooves on barrels inner surface Improves accuracy Can identify weapons manufacturer Imprints different scratch patterns on bullets Caliber: the internal diameter of the gun barrel

 The amount of grooves and lands and the direction and rate of twist in a gun are characteristic of one product and one creater  Striations are formed possibly from imperfections of the surface of the broach cutter or from shards of steel that is made into wedes when it is caught between the broach cutter and the barrel wall  The individual marks left on bullets are individual marks that allow a forensic specialist to match the bullet to the gun it came from

 The larger of caliber the weapon is, the greater the kinetic energy it has when fired from the gun  The larger the caliber, the wider the bore of the barrel and the larger the bullet is has to be to fill that bore  The greater the projectile’s velocity, the greater kinetic energy that the bullet has

 Flintlock rifle: a single-shot rifle that uses a spark to ignite the gunpowder that is loaded in the barrel The firing mechanism was temperamental and very difficult to fire into the rain The rate of firing was also slow

 Compact weapons that are able to fire with one hand  Multiple shots without the need of reloading  Shoots bullet fast enough to stop an attacker but recoil on gun not too powerful to force gun out of gunman’s hand

 Revolvers  Generally 6 shots  Easy to use and handle  Cheap to purchase and easy to clean  Theres single and double action  Single the hammer has to be cocked  Double you just need to pull the trigger

 Revolvers  Barrel length is short making it easy to conceal  Cartridges stay in gun after being shot

 Semiautomatic pistols  Uses recoil from gun to reload the next round into chamber  Holds anywhere from 10 to 19 rounds  Are more complicated and jam sometimes  After each shot the gun ejects the cartridge which are found at crime scenes

 Silencers Attach to a handgun Reduce the amount of noise generated by firing the weapon

 Submachine guns Can fire automatically like a machine gun but use pistol ammunition Are small and lightweight Preferred by security details because they are small and easy to conceal

 Differ from handguns in that they have a long barrel and butt stock  Are hard to conceal, but much more accurate than handguns  Come as single-shot and multiple-shot models  Are popular choices for hunters

 Are desired for bird hunters  Shoot a large number of small pellets that disperse in a circular pattern  Have a butt stock and a long barrel, but lack rifling inside the barrel The diameter of the barrel is expressed as a gauge A higher gauge means a smaller barrel and less kinetic energy

 Commercially Available version: singe- shot, double-barrel, bolt-action, pump- action, and semiautomatic models  Sawed-off shotguns: created by cutting down the barrel and the stock  Are easier to conceal  Deliver more damage per shot at close range, but are less effective over long distance

 Bullets: designed with an aerodynamic shape that has a parabolic front and a wind-splitting shape  Cartridges: consists of a brass case that contains a primer, gunpowder, and a bullet  Shotgun shells: May contain a bore-size projectile (slug), pellets of a large shot, or many tiny pellets