the combustion products are expelled therefore a presence of lead, barium and antimony confirm discharge of a firearm
Round nose & full metal jacket – pass through a target when they don’t hit something significant like bone
Big focus today in bullet design – bullet that has an expanding point – expansion is needed to slow down the bullet when it strikes an object A bullet that expends all of its energy in a target is more efficient and produces more damageneed a bullet to pass through a car window , heavy clothing
.32 caliber S&W – 5 lands and grooves with a right hand twist (clockwise).32 caliber Colt – 6 lands and grooves with a left hand twist (counterclockwise)
parallel set of scratches on a bullet caused by markings on the bore can be matched to a weapon or bullets from other crime scenesmicroscope is necessary to see marks
Head stamp -numerals, letters, symbols on base of cartridge showing manufacture caliber and code Rim – primer on circumference base Centerfire – primer in center of base
Dawson Meets Basil in "The Great Mouse Detective" - you tube
Jacketed soft point Lead round nose Wad - cutterFull – metal jacket Jacketed hollow point Semi wad-cutter
Individual ClassStriae BullettypeFiring pin marks Bullet caliber Bullet weightBreech marks Lands and groovesExtractor marks RiflingEjector marks Cartridge caseChamber marks Head stamp
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