Firearms and Toolmarks

Study Guide #21 Firearms and Toolmarks

Types of Weapons

Revolver

Pistol Cutaway

Revolver Cutaway

Test Firing

Ballistics and Rifling

Ballistics - the science of motion
Rifling
Grooves: spiral grooves dug in barrel of weapon to cause bullet to spin as it leaves barrel
Lands: raised areas between grooves
Usually 4-7 lands and grooves in a barrel

Comparison Microscope

Bullet Stria Comparison

Improper Labeling of a Bullet

Markings on Cartridges

Firing Pin Impression

Breech Face Markings

Other Firearms Analyses

Bullet Hole in Glass

Effects of a Contact Shot

Effects of a Distance Shot

Anatomy of a Bullet Hole

Tight Contact

3 Inches

6 Inches

18 Inches

Sequential Bullet Holes

Restoration of a Weathered Weapon

Weapon Restortation