Forensic Ballistics - Firearms, Types, Classification, Ammunition: UGC NET Forensic Science

UGC NET Forensic Science: Forensic Ballistics - Firearms, Types, Classification, Ammunition

Comprehensive notes and question pattern analysis for UGC NET Forensic Science aspirants, focusing on firearms and ammunition in forensic ballistics.

Part 1: Notes on Forensic Ballistics - Firearms, Types, Classification, Ammunition

1. Introduction to Forensic Ballistics

Forensic ballistics is the study of firearms, ammunition, and their effects in criminal investigations. It involves analyzing firearms, bullets, and gunshot residues to link weapons to crimes.

Key Concepts

• Firearms: Mechanical devices that propel projectiles using explosive force.
• Ammunition: Components (bullet, propellant, primer) used in firearms.
• Forensic Relevance: Identification of firearms, bullet matching, trajectory analysis.

2. Firearms: Types and Classification

Firearms are classified based on their mechanism, barrel, and purpose.

2.1. Types of Firearms

• Handguns: Pistols (semi-automatic), revolvers (rotating cylinder).
• Rifles: Long-barreled, rifled bore (e.g., bolt-action, automatic).
• Shotguns: Smoothbore, fire shot or slugs.
• Machine Guns: Fully automatic, high firing rate.

2.2. Classification of Firearms

Category	Criteria	Examples	Forensic Notes
Bore Type	Smoothbore vs. Rifled	Shotgun (smooth), Rifle (rifled)	Rifling imparts spin, identifiable marks.
Action	Single-shot, semi-automatic, automatic	Single-shot pistol, AK-47 (automatic)	Action affects firing rate, evidence type.
Purpose	Military, civilian, law enforcement	M16 (military), Glock (law enforcement)	Purpose influences ammunition type.
Caliber	Bore diameter (mm or inches)	9mm, .45 ACP	Caliber aids in weapon identification.

3. Ammunition and Their Compositions

Ammunition consists of a cartridge with multiple components.

3.1. Components of Ammunition

• Bullet/Projectile: Lead, copper-jacketed, or hollow-point; imparts damage.
• Propellant: Gunpowder (nitrocellulose) or smokeless powder; generates gas pressure.
• Primer: Percussion-sensitive compound (e.g., lead styphnate); initiates combustion.
• Cartridge Case: Brass, steel, or aluminum; holds components.

3.2. Types of Ammunition

• Centerfire: Primer in the center (e.g., 9mm Parabellum).
• Rimfire: Primer in the rim (e.g., .22 LR).
• Shotgun Shells: Plastic casing with shot or slug.

3.3. Composition Analysis

Component	Material	Forensic Significance
Bullet	Lead, copper, steel	Rifling marks, striations for matching.
Propellant	Nitrocellulose, nitroglycerin	Residue analysis (GSR) via SEM-EDX.
Primer	Lead styphnate, barium nitrate	GSR particles indicate firing proximity.
Cartridge Case	Brass, steel	Ejector, firing pin marks for firearm ID.

4. Forensic Significance

• Firearm Identification: Matching bullets/cartridges to a specific weapon via rifling marks.
• Gunshot Residue (GSR): Detects firing through antimony, barium, lead analysis.
• Trajectory Analysis: Determines bullet path for crime scene reconstruction.
• Chain of Custody: Ensures evidence integrity for court admissibility.

Part 2: Deep Analysis of NTA-UGC NET Forensic Science Question Pattern

1. Overview of UGC NET Forensic Science Exam

The exam consists of Paper 1 (general aptitude) and Paper 2 (Forensic Science, Code 82), with 100 MCQs in Paper 2 (200 marks).

2. Question Pattern Analysis for Forensic Ballistics

2.1. Frequency and Weightage

4–8 questions per cycle (8–16 marks), focusing on firearm types, ammunition, and forensic analysis.

2.2. Types of Questions

• Factual: “Which firearm has a smoothbore barrel?”
• Application: “Which component of ammunition leaves GSR?”
• Analytical: “Which technique identifies rifling marks?”
• Case-Based: “A bullet has spiral grooves. Which firearm was used?”

2.3. Difficulty Level

• Easy: Firearm types, ammunition components.
• Moderate: Classification, GSR analysis.
• Difficult: Rifling mark analysis, trajectory reconstruction.

2.4. Topic Distribution (2004–2025)

• 2004–2012: Basic firearm types, ammunition components.
• 2013–2019: Emphasis on GSR, rifling marks, comparison microscopy.
• 2020–2025: Questions on trajectory, improvised firearms, forensic significance.

Sample Questions

Which firearm has a smoothbore barrel?

A) Rifle

B) Shotgun

C) Pistol

D) Machine Gun

Answer: B) Shotgun
Explanation: Shotguns have smoothbore barrels, firing shot or slugs, unlike rifled barrels in rifles.

Which technique is used to analyze gunshot residue (GSR)?

A) FTIR

B) SEM-EDX

C) GC-MS

D) HPLC

Answer: B) SEM-EDX
Explanation: SEM-EDX detects GSR particles (lead, antimony, barium) with high specificity.

Preparation Tips

• Memorize firearm types and classifications.
• Understand ammunition components and their forensic significance.
• Practice analytical techniques (SEM-EDX, comparison microscopy).
• Solve previous years’ papers (2019–2025).