Bullet Analysis

Bullet Anatomy Bullet- actual projectile Case- holding container Powder Charge- source of explosion energy Primer- igniter Wad- (for shotgun shells) plastic separator from the pellets and powder. *Note this is present in shotgun shell blanks and can potentially be deadly at close range. Gun Barrel Rifling Traditional sharp-edged "lands and grooves" are replaced by less pronounced "hills and valleys", so the barrel bore has a polygonal (usually hexagonal or octagonal) cross-sectional profile. Firing Pin and Ejector MarksBolt‐Face Signature Firing Pin- Leaves an impression when it strikes the primer of center fire cartridge cases or the rim on rim fire cartridge cases. Ejector marks- are caused when the cartridge are ejected from the firearm and can be used to confirm passage through a firearm Bullet Striations These are like a guns “fingerprint” Even the same make and model of firearm will produce distinctive striations The pattern will typically hold true even over time. Bullet Lands and Groves = Rifling Lands are the raised portions between the grooves inside the barrel after the spiral grooves are cut to produce the rifling. Bullet Unique Characteristics Number of lands and grooves usually 4 to 6 but range from 2 to 22 Diameter of lands and grooves. Width of lands and grooves. Depth of grooves. Degree of twist (twist is the number of inches of bore required for one complete rifling spiral). Link to Lecture Slides: https://drive.google.com/file/d/1bR7vAGUOaIgExXkC_xKzUaBhiXQvFPM3/view?usp=sharing *Due to the description character limit the full work cited for "Bullet Analysis" can be viewed at... https://drive.google.com/file/d/1KQZBDFeQ-isK-3QWM0x2FUfvgYkJZP_C/view?usp=sharing