Ballistics 1
www.Firearmsid.com
Firearms and ballistics webquest
1. Go to: https://www.firearmsid.com/A_Introduction.htm
The answers to the following can be found by going through the menu of pages listed on the
left. Pages match these headings – click “next” to proceed through.
INTRODUCTION:
o The identification of fired bullets, cartridge cases or other ammunition components as
having been fired from a specific firearm is the area known as
_____________________. It is often incorrectly referred to as ______________.
o What type of evidence is usually processed at the firearms division of the forensics lab?
o T/F Once the evidence is analyzed by the firearms technician, he/she is relieved of
further responsibilities.
FUNDAMENTALS OF FIREARMS ID
o What two principles are used when identifying firearms?
o ________% of firearms produce a “___________ fingerprint” on _____________and
cartridges.
o The first part of firearm examination involves the examination of ____________
characteristics, which means the:
o Examples of firearm class characterisitics are:
o After similar class characteristics are determined, __________________
characteristics are identified.
BULLET IDENTIFICATION
o Name the two class characteristics of bullets: _________________ and
__________________
o Scratches or microscopic _______________ are transferred from the gun __ to the
bullet.
o These patterns can be ___________ which means different for each bullet.
o Questioned bullets are usually damaged or even broken into _____________.
o Standard bullets are fired into a _________ ______________.
o Evidence and standard bullets are compared on ______________
_____________________.
CALIBER
o Caliber of a bullet is the _____________ in __________ of an inch.
o In Europe, caliber is measured in __________.
o Bullets are contained in ___________ which contain primer, ______________ and
_____________.
o What do cartridge designations tell you?
o How can bullets vary?
o Explain why finding a questioned bullet doesn’t tell you what cartridge the bullet came
from.
RIFLING
o What is rifling?
o What does rifling do?
o What is a ‘land’?
o Name three main processes to form rifling in gun barrel.
__________________, _______________, _______________
o Which rifling process does Glock use?
o Which method does not require consumable tools?
o How does polygonal rifling differ from traditional rifling?
RIFLING IMPRESSIONS
o
A bullet is (larger/smaller/ same) size as the barrel from which is it fired?
o How is bore diameter measured?
o How do you determine rifling pattern and direction of rifling?
o What can be different about 2 bullets, both fired from a 6/right rifled barrel?
o What is rate of twist?
o Rifling direction is hard to determine with (low/high) pitch?
o What is pitch?
o What can happen to a bullet that makes all of its class characteristics hard or impossible
to determine?
GENERAL RIFLING CHARACTERSTICS (GRC)
o What are general rifling characteristics?
o What is the general tolerance in measuring/searching for the width of lands and grooves?
o Who maintains a database of rifling data?
CARTRIDGE CASE IDENTIFICATION
o Name two identification differences between bullets and cartridges.
o Striation action marks are:
o Impressed action marks are:
STRIATION ACTION MARKS
o Striation action marks are found on _______________
o How are chamber marks formed?
o What is the difference between an extractor and an ejector?
IMPRESSED ACTION MARKS
What causes impressed action marks?
Two most common impressed action marks are:
T/F Firing pin impressions are found only on spent cartridges
Recoil is:
Where is the breech face found in a firearm?
What are some different types of breech marks?