Name: _________________________________________ Per: ___________ Date: ________________

Unit 8: Firearms & Ballistics

By the end of this unit, you will be able to: Explain the differences between a handgun, a rifle, and a shotgun Describe the rifling on a gun barrel and how it affects the flight of the

projectile Explain barrel size and caliber Describe how bullets are test fired and matched Discuss the role of ballistics recovery and examination at a crime scene Determine the position of the shooter based on bullet trajectory

Unit Vocabulary: Cartridge:

____________________________________________________________________ Muzzle:

_______________________________________________________________________ Groove_______________________________________________________________________ Land (ridges):

________________________________________________________________

Unit 8: Firearms and Ballistics 1

Name: _________________________________________ Per: ___________ Date: ________________

Caliber: ______________________________________________________________________ Gunshot residue (GSR):

________________________________________________________ Trajectory: ___________________________________________________________________

Introduction Ballistic evidence helps explain:

o What __________________________________ was used o The ______________ of the bullet o The _____________ of bullets fired o _____________ the shooter was _____________________ o Whether a weapon was fired ____________________ o If a firearm was used in _________________________________

History of Gunpowder and Firearms ______________________ invented gunpowder

over a thousand years ago Muzzle – loading matchlocks used wicks to

ignite the gunpowder Flintlock weapons used a spark from a chip of

flintPercussion Firing Weapons

______________________ - holds bullet, primer powder, gunpowder

______________________ hits primer powder which ________________ the gunpowder

Breech loading is faster than muzzle loading.Long Guns and Handguns

_______________________ o Rifles fire bullets o Shotguns fire pellets

(_________) or a single projectile (__________)

_____________________ o Pistols are fired with _______________o Revolvers have a cylinder that holds usually

________ cartridges __________________________ – 10 cartridges into a

_____________________. Fires one bullet per pull of trigger

___________________ – fires repeatedly as trigger is pulled

Unit 8: Firearms and Ballistics 2

Name: _________________________________________ Per: ___________ Date: ________________Firearms and Rifling

___________________________________ in the barrel of a gun produce the twisting that adds ___________________

This leaves a pattern on the bullet that is ________________ Bullets, Cartridge, and Caliber

________________________—a case that holds a bullet, primer powder, and gunpowder

The bullet, usually of metal, is out front with the cartridge, holding the primer and propellant powders, behind.

How a Firearm Works1. The firing pin hits the base of the ____________, igniting

the ______________________________ 2. The primer powder ______________ through the flash

hole to the main propellant supply 3. The _______________________________________ pushes the

bullet from the casing into the barrel 4. The bullet follows the ____________________________________ out of the barrel

Caliber of the Cartridge _____________________—a measure of the diameter of the

cartridge In hundredths of an ______________ Common calibers include

Unit 8: Firearms and Ballistics 3

Name: _________________________________________ Per: ___________ Date: ________________

o .22, .25, .357, .38, .44, and .45

Question: Why should the caliber of ammunition match the firearm that shoots it? If they do not match, what could go wrong?

o Discuss this this your neighbor! Write down your thoughts AND their thoughts

I think: __________________________________________________________ _________________________________________________________________

My neighbor ________________ thinks: _____________________________ _________________________________________________________________

The Study of Bullets and Cartridge Casing

Matching Bullets Gun is “test-fired” into

______________________________. _________________________________ _________________________________

to suspect’s weapons, bullets, casings.

Marks in the Spent Cartridge Casing ______________________________________

o Appear on the rim or center of the spent cartridge o Can be used to match a cartridge to a firearm

______________________________________o Produced when the cartridge casing slams backward and strikes the

breechblock ______________________________________

o Only in semi-auto and automatic weapons o Small scratches

Unit 8: Firearms and Ballistics 4

Name: _________________________________________ Per: ___________ Date: ________________Gunshot Residues

________________________________ (GSR) o Particles of _____________________________ and traces of smoke o Leave _______________ on the hand, arm, face, hair, or clothing of the

shooter and/or victim Chemical testing can detect residue _________________________________________ ____________________ from victim to shooter can be determined by examining

the residue pattern on the victim o Question: Do you think there is a relationship between the

distance between the victim and shooter and the amount of gunshot residue? What do you think that relationship is? Discuss with your neighbor.

_________________________________________________________________Bullet Wounds

Can show what _________________________________ o Was the victim running away?

________________ wounds are ____________ than exit wounds o Skin stretches as bullet enters o As bullet moves through the body it collects tissue

_________________ may point in the direction the bullet moved ___________ found near entrance wounds ___________________ may burn skin if gun was close ___________________ bullets tend to remain _______________ in the body

Trajectory __________________

_________________ are needed to define the trajectory

Investigators can figure the shooter discharged the firearm somewhere along that line

Reference points can be

o Bullet holes in objects or victims

o An entry point and exit point on a victim

o Gunshot residue or spent cartridge casings

Unit 8: Firearms and Ballistics 5

Name: _________________________________________ Per: ___________ Date: ________________

________________ can trace a straight-line path to determine the position of the shooter

Trajectory and Gravity

Bullet’s path is slightly _____________ Gravity pulls it downward as the bullet

moves forward Wind can affect trajectory Bullet can hit other objects and ricochet

Unit 8: Firearms and Ballistics 6