Basics of Firearms and Ballistics

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Questions and Answers

What does ballistics refer to?

The study of the motion of projectiles (correct)

The study of fire safety

The analysis of fingerprints

The analysis of DNA evidence

Who is known as the Father of Modern Ballistics?

Calvin H. Goddard

Alexander John Forsyth is known as the father of Percussion ignition.

True

______ is the metallic or non-metallic object propelled from the firearm by means of heated gas.

Projectile Signup and view all the answers

Match the inventor with their invention:

Samuel Colt = First practical revolver Hiram Maxim = Machine gun or the Maxim gun Richard Gatling = Gatling gun, a machine gun with six barrels David Carbine Williams = Invented the carbine firearm Signup and view all the answers

What type of firearm is required for the transport of airsoft rifles/pistols from the place of residence to any game or exhibition site?

Permit To Transport (PTT) Signup and view all the answers

Which firearm type is designed to slide back and forth by grasping the forearm located under the barrel?

Slide/Pump Action Type Signup and view all the answers

Ball bullets have a soft lead core inside a jacket and are used against vehicles.

False Signup and view all the answers

A _ is a projectile propelled through the barrel of a firearm by means of an expansive force of gases.

bullet Signup and view all the answers

Match the cartridge case types with their descriptions:

Rimmed Type = The diameter of the rim is greater than the diameter of the body of the cartridge case Semi-Rimmed Type = The diameter of the rim is slightly greater than the diameter of the body of the cartridge case Rimless Type = The diameter of the rim is equal to the body of the cartridge case Belted Type = There is a protruding metal around the body of the cartridge case near the rim Signup and view all the answers

What are class characteristics?

Class characteristics are factory specifications and markings that are determinable even prior to the manufacture of firearms. Signup and view all the answers

What are individual/accidental characteristics?

Characteristics peculiar in a particular striation Signup and view all the answers

The ___ is the distance advanced by the rifling in one complete turn or a distance traveled by the bullet in one complete turn.

pitch Signup and view all the answers

Slippage marks are caused by the rotating resistance of the bullet upon entering the rifling of the breech end.

False Signup and view all the answers

Match the following rifling types with their descriptions:

Broach, gang = A tool with cutting edges used to cut spiral grooves in a barrel Scrape = A cutting tool that cuts opposing grooves at the same time Button = A hardened metal plug used to eject shells from the barrel Hook = A cutting tool that cuts grooves one at a time Signup and view all the answers

What type of microscope is used to determine the similarity and dissimilarity between two fired bullets or fired cartridge cases?

Comparison microscope Signup and view all the answers

What discipline of forensic science concerns determining if a tool mark was produced by a particular tool?

Tool marks identification Signup and view all the answers

What type of tool mark is left by a tool scrapping over a surface softer than itself?

Striated toolmark Signup and view all the answers

Which equipment is used to determine the weight of bullets, shots, and pellets?

Analytical Balance Signup and view all the answers

A Tool Mark Identification can determine the source tool of an impression mark left on a window frame.

True Signup and view all the answers

Study Notes

Ballistics

The study of ballistics covers the motion of projectiles and the conditions affecting such motion, from the time the gunpowder explodes to the time the projectile strikes the target.
Derived from the Greek word "Ballo" or "Ballein", meaning to throw.
Also derived from the early Roman War machine "Ballista", which hurled missiles or large objects.

History of Ballistics

Calvin H. Goddard - considered the Father of Modern Ballistics, invented the Bullet Comparison Microscope.
Horace Smith and Daniel Wesson - founded Smith and Wesson and pioneered the making of breech-loading rifles and revolvers.
John M. Browning - known as the Wizard of Modern Firearms, pioneered the breech-loading single-shot rifle.
David Carbine Williams - invented the carbine firearm.
Alexander John Forsyth - known as the father of Percussion ignition.
Samuel Colt - produced the first practical revolver.
Sir Hiram Maxim - invented the machine gun (Maxim gun).
Richard Gatling - invented the Gatling gun, a machine gun with six barrels capable of firing 200 rounds per minute.

Ballistic Fingerprinting

The study of firearm, ammunition, and tool mark evidence to establish whether a certain firearm or tool was used in the commission of a crime.

Interior Ballistics

The study of the motion of the projectile while still inside the gun barrel.
Covers the time from loading the firearm to the explosion and the movement of the bullet towards the muzzle end of the gun.
Subjects of study include:
- Firing pin striking the primer
- Ignition of the propellant mixture
- Combustion of gunpowder
- Expansion of heated gas in the chamber
- Pressure developed
- Energy generated
- Recoil of the gun

Exterior Ballistics

The study of the motion and traits of projectiles after leaving the muzzle of the gun.
Covers the trajectory, range, and other aspects of the bullet's flight.
Subjects of study include:
- Muzzle blast
- Muzzle energy
- Trajectory
- Range
- Air resistance
- Pull of gravity
- Gyroscopic stability
- Penetration

Terminal Ballistics

The study of the effect of the impact of the bullet on the target.
Subjects of study include:
- Terminal accuracy
- Terminal energy
- Terminal velocity
- Terminal penetration

Forensic Ballistics

The investigation and identification of firearms by means of ammunition fired from the submitted suspected firearms.
Phases include:
- Field investigation
- Preparation for court trial### Bullet Types
Dum-Dum Bullet: invented by British Ordinance force at Dum-Dum, India
Primer: metal cup containing sensitive priming mixture of chemical compound
- Composition:
  - Potassium Chlorate (45%)
  - Antimony Sulfide (23%)
  - Fulminate of Mercury (32%)
Classification of Cartridges according to Rim:
- Rimmed Type: diameter of rim greater than diameter of body
- Semi-Rimmed Type: diameter of rim slightly greater than diameter of body
- Rimless Type: diameter of rim equal to body
- Rebated Type: diameter of rim smaller than body
- Belled Type: protruding metal around body near rim

Cartridge Case Types

Pin-Fire Cartridge: pin extends radially through bead of cartridge case into primer
Rim-Fire Cartridge: priming mixture in cavity formed in rim of cartridge case
Center-Fire Cartridge: primer cup in middle portion of head of cartridge case
Percussion: means of ignition of propellant by mechanical blow against primer or percussion cap

Gunshot Residue (GSR) Tests

Paraffin-Diphenylamine Test: used to determine presence of GSR
Sodium Rhodizonate Test: chemical test to determine presence of lead styphnate
Walker Test: chemical test for presence of nitrates/nitrites in unburned or partially burned propellants
Marshal and Tiwari Test: used to determine firearm distance and detect nitrates/nitrites

Marking of Fired Bullets

Initials or date of recovery marked on bullet or cartridge case
No 'X' mark should be used to avoid confusion

Class Characteristics vs Individual Characteristics

Class Characteristics: factory specifications, within control of manufacturer (e.g. bore diameter, number of lands, number of grooves, width of lands, twist of rifling)
Individual/Accidental Characteristics: peculiar marks or striations that do not appear in all other firearms

Rifling Methods

Broach, Gang: tool with series of cutting edges to cut spiral grooves in barrel
Broach, Single: non-adjustable rifling cutter that cuts all grooves simultaneously
Button: hardened metal plug with rifled cross-section configuration, pushed or pulled through drilled and reamed barrel
Hook: cutting tool that cuts one groove at a time
Scrape: cutting tool that cuts two opposing grooves at a time
Swage: internal mandrel with rifling configuration that forms rifling in barrel by external hammering

Principles of Identification of a Bullet

No two barrels are microscopically identical
Every barrel leaves its unique marks on every bullet fired through it
The firearm leaves its "fingerprints" or "thumb mark" on every cartridge case it fires

Types of Problems

Type 1: determine caliber and type of firearm from a bullet
Type 2: determine caliber and type of firearm from a fired cartridge case
Type 3: determine whether a bullet was fired from a suspected firearm
Type 4: determine whether a cartridge case was fired from a suspected firearm
Type 5: determine whether two or more bullets were fired from the same firearm
Type 6: determine whether two or more cartridge cases were fired from the same firearm

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Description

Explore the fundamentals of firearms and ballistics, including the definition of ballistics, key figures in its development, and essential concepts related to firearms.