ballistics study guide

What are striation marks and what causes them?
Striation marks are distinctive scratches or grooves that appear on a bullet's surface, which occur as the bullet travels down a rifled barrel.

Do any rifled barrels ever leave the same striation marks?
No, rifled barrels never produce identical striation marks; each barrel creates unique markings due to slight variations in its design.

Does a shotgun barrel have lands and grooves?
Shotgun barrels lack lands and grooves, as they are smooth bore barrels without the rifling typical of other firearms.

What is class evidence and individualize evidence? Explain how they relate to gun barrels.
Class evidence refers to characteristics shared by a group, such as the general features of a gun barrel, while individualizing evidence points to specific, unique traits, like striation marks that match a particular barrel.

Explain internal ballistics.
Internal ballistics deals with the processes that occur inside the firearm while the bullet is being fired, from ignition to the moment the bullet exits the barrel.

Explain external ballistics.
External ballistics concerns the behavior of the bullet after it leaves the barrel, including its flight path and any factors that affect its trajectory.

Explain terminal ballistics.
Terminal ballistics focuses on what occurs when the bullet impacts its target, such as the damage caused and the bullet's energy transfer.

What is the difference between lands and grooves?
Lands are the raised parts inside a barrel, while grooves are the recessed areas between them, both playing a role in imparting spin to the bullet.

What is firearms identification?
Firearms identification is a specialized branch of ballistics that determines whether a particular firearm fired a specific bullet or cartridge.

Where would you find gunshot residue?
Gunshot residue can be found on the shooter’s hands, clothing, face, or hair, as well as on the victim if they were in close proximity to the shot.

Why is rifling necessary in a firearm?
Rifling is essential because it spins the bullet as it travels down the barrel, significantly improving accuracy and stability during flight.