Unformatted text preview: ination, but not individualization, can occur here The role of FA/TM examiners The role of FA/TM examiners
► Did this gun fire this ammunition component? ► Did the same gun fire these ammo components? ► What possible gun could have fired these ammo components? ► Is this firearm functional? ► S/N restoration ► Did this tool produce this mark? ► How far was the shot fired from? Firearms Fundamentals Firearms Fundamentals
► Rifling: helical grooves ► Spin stabilization ► Rate of twist ► Rotation direction ► Lands/grooves ► Cut vs. polygonal rifling The caliber of a rifled weapon is generally determined from the diameter of the bore, measured between two opposite lands. There are, however, exceptions to this rule. (A) caliber, (B) land, (C) barrel, (D) groove. Cross-section of barrel with traditional rifling. Right-hand twist. Center fire Ammunition Center fire Ammunition Power-Piston opening up on leaving barrel. 9 pellet stack Federal Tactical Shot cup – 8 Federal Tactical Shot cup – 8 pellet load Center fire Cartridge Center fire Cartridge
Head stamp markings Primer FP impression Rim Base (Head) Rim fire FP imp Rim fire FP imp Discharge Discharge Breech Face of Weapon Breech Face of Weapon FP aperture FP Cartridge case markings Cartridge case markings
BFMs FP imp Cartridge case comparison Cartridge case comparison Typical Breech Face Typical Breech Face Marks From a Glock BF Marks on Primer BF Marks on Primer BF Marks BF Marks Firi...
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- Spring '11
- Rifle, Rifling, Smoothbore, Toolmark Identification, Individual Characteristics