14. Jacketed soft point Lead round nose Wad - cutter
Full – metal jacket Jacketed hollow point Semi wad-cutter
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22. Individual Class
Striae Bullettype
Firing pin marks Bullet caliber
Bullet weight
Breech marks
Lands and grooves
Extractor marks
Rifling
Ejector marks
Cartridge case
Chamber marks Head stamp
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