Firearms%20and%20Ballistics1

Firearms%20and%20Ballistics1 - Firearms, Tool Marks, and...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
Firearms, Tool Marks, and Other Impressions Dr. Perr
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Handguns Firearms, Tool Marks, Impressions
Background image of page 2
Rifling Rifles and handguns have “rifled” barrels • Spiral grooves in barrel that impart spin to bullet when fired • “Twist” = # of inches for one complete rifling spiral – right (clockwise) or left-handed (counterclockwise)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Lands and Grooves
Background image of page 4
What’s in Ammunition? • Cartridge case • Primer • Propellant • Bullet
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Cartridge Case Brass (70%Cu, 30%Zn) Expand and seal chamber against rearward escape of gas Classified by type of rim Headstamps
Background image of page 6
Primer “Centerfire” or “Rimfire” Firing pin strikes primer cup, compressing it against anvil, causing explosion Chemical composition Lead styphnate Barium nitrate Antimony sulfide
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Propellants • Historically, black powder (charcoal, sulfur, potassium nitrate) – full combustion: 44% mass in gas, 56% in residue • Now, smokeless powder – single base (nitrocellulose) – double base (nitrocellulose, nitroglycerine) – triple base (nitrocellulose, nitroglycerine, nitroguanidine)
Background image of page 8
• Historically, lead spheres – Poor aerodynamics • Now, two types – Lead bullets – Metal-jacketed bullets
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/06/2011 for the course CHS 3501 taught by Professor Perr during the Spring '09 term at FIU.

Page1 / 25

Firearms%20and%20Ballistics1 - Firearms, Tool Marks, and...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online