Components of gun powder

 

Classification of Bullets

Forensic Ballistics: Ammunition & Terminal Effects

1. Classification by Construction

Type Characteristics
Lead (Plain) Solid lead alloy; used for target practice/revolvers.
Full Metal Jacket (FMJ) Lead core encased in a harder metal (copper/brass) to reduce barrel fouling.
Hollow Point Cavity in the nose; designed to expand on impact to maximize energy transfer.
Soft Point Jacketed bullet with an exposed lead tip to allow controlled expansion.

2. Classification by Purpose

  • Armor-Piercing: Contains a hardened core (steel/tungsten) to penetrate metal or protective plating.
  • Tracer: Contains pyrotechnic chemicals (e.g., phosphorus) to create a visible path during flight.
  • Incendiary: Designed to ignite flammable targets upon impact.
  • Frangible: Designed to disintegrate into powder upon hitting a hard surface to minimize ricochet risk.

3. Forensic High-Yield Pearls

  • Class Characteristics: Include caliber, number of lands and grooves, and direction of rifling twist. These help narrow down the *type* of firearm used.
  • Individual Characteristics: Microscopic striations (ballistic “fingerprints”) produced by imperfections in the gun barrel, used to match a specific bullet to a specific weapon.
  • Terminal Ballistics: The study of how different bullet types interact with human tissue (e.g., expansion vs. penetration), which is critical for interpreting gunshot wounds.
  • Wadcutter: Specifically designed with a flat nose to cut clean holes in paper targets, making them distinctive in forensic scene reconstruction.