Firearms Question and answer 100% solved 2023

Firearms Question and answer 100% solved 2023What is Firearm Identification? a. Every firearm has individual, unique characteristics that are present from manufacture b. Incidental damage adds to uniqueness from manufacture c. Those features are impressed into fired ammunition components d. Microscopic comparison of the individual characteristics leads to identification. e. Identification is NOT true ballistics. St. Valentine's Day Massacre a. February 14, 1929 b. 7 gangsters murdered in Chicago. c. Calvin Goddard microscopically examined the fired evidence and later recovered firearms for identification purposes. d. Established the Bureau of Forensic Ballistics at Northwestern University. Firearms Evidence a. 70 fired 45 Automatic caliber cartridge cases total b. 20 fired in 1st gun c. 50 fired in 2nd gun d. 45 caliber bullets fired from 2 different barrels e. 2 shotgun blasts obliterated the faces of two victims How a Firearm Works a. Trigger is pulled b. Firing pin strikes primer on cartridge c. Primer ignites gunpowder in cartridge d. Burning gunpowder causes gas to expand (pressure) that pushes bullet down the barrel e. Bullet exits barrel at muzzle Types of Firearms a. 3 major types - rifles, handguns, & shotguns b. Action types - How the firearm operates: Single shot, Multiple barrel (double barrel, drilling, others), Pump, Lever, Bolt, Revolving, Semi-automatic (one shot per trigger pull), Full-automatic (more than one shot per trigger pull) c. Some firearms can have an identity crisis Rifle & Handgun Ammunition a. Major Components i. Cartridge case ii. Primer iii. Gunpowder iv. Bullet b. Centerfire vs. Rimfire What is Caliber?? Two parts to a whole i. Caliber of the cartridge case (size, shape, type, working pressure) ii. Caliber of the bullet (diameter, shape, weight) iii. Unfired cartridge = fired bullet + fired cartridge case Caliber Designation or Name a. Cartridge name origins: i. Size of bullet ii. Size of cartridge case iii. Inventor or Manufacturer iv. Year of introduction v. Many others b. The same caliber can have different names based on location & application 380 Automatic (US) a. 380 A.C.P b. 9 x 17mm c. 9mm Browning Short d. 9mm Kurz e. 9mm Corto Shotshell Ammunition a. Shotshell size determined by gauge. b. 5 major components: Primer, Hull, Gunpowder, Wad, Projectile c. 3 typical projectile types: Birdshot (small pellets), Buckshot (large pellets), and Slugs (one big bullet) Firearms & Ammunition In Relation to Forensic Identification Areas on firearms that leave marks on fired cartridge cases & shotshells. i. Breech face ii. Firing pin iii. Extractor iv. Ejector v. Barrel Chamber vi. Others Class Characteristics (Sig-Sauer) i. Parallel breechface marks ii. Hemispherical firing pin iii. Extractor on right iv. Ejector on left Class Characteristics (Walther P-38) i. Circular breechface marks ii. Hemispherical firing pin iii. Extractor on left iv Ejector on right Individual Characteristics a. Unique marks left behind from manufacture b. Originate from randomness of manufacture c. Can get "more unique" from misuse and abuse