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Firearms Examiner Training

Module 03: Propellants, Ammunition, and Firearms Development

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Illustration of a gun being fired, as well as photographs of rifle firing mechanisms
National Institute of Justice (NIJ) (see reuse policy).


Author: J. Allan Jones
J. Allan Jones obtained a Bachelor of Science degree (1969) from Southern Methodist University and continued graduate studies there until 1971, when he joined the Dallas County (Texas) Institute of Forensic Sciences Crime Laboratory as a firearm examiner. Mr. Jones worked in that capacity until 1987, when he moved to Lewiston, Idaho, as the manager of technical publications for CCI Ammunition and Speer Bullets. He directed ballistics research for and authored Speer Reloading Manual, numbers 12, 13, and 14. Mr. Jones retired from CCI/Speer in 2007.



Knowledge of the evolution of small-arms systems for sporting and military purposes is important for the student of firearms identification. The individual components of the system firearms and ammunition are closely interrelated. Small improvements in one continue to lead to small improvements in the other. Understanding this evolution will make the student a better firearm examiner and witness.

As an evolutionary overview, this discussion follows the significant milestones showing how today's technology is connected to the past and tracing the key lines of growth. It is a story of constant improvement, of new strengths from old weaknesses, and of the incredible inventiveness of the human mind.


At the conclusion of this module the student should be able to

  • describe in detail the evolution of propellants from black powder to modern propellants,
  • describe the evolution of firearm projectile design and composition,
  • define the primary developments in small-arms design including
    • ignition systems,
    • rifled barrels,
    • breech-loading systems,
    • repeating mechanism
  • define ammunition components,
  • define the primary developments in ammunition evolution including
    • bullets,
    • case design
  • describe primer development.


AFTE Knowledge and Ability Factors

73.Knowledge of historical development of firearms design
75.Knowledge of muzzleloading firearms designs, including ignition systems and loading techniques
76.Knowledge of breechloading firearms designs, including falling breechlocks (falling block action), bolt actions, lever actions, (slide)/pump actions, break-open (top break) semiautomatics (blowback, gas operated, recoil operated, etc.), revolvers--double and single action
77.Knowledge of firearms ignition systems: flintlock, percussion, rimfire, centerfire, caseless ammunition
81.Knowledge of the proper operation of the different types of firearms encountered in casework
85.Knowledge of propellants: physical forms and associated purposes of small-arms propellants; black gun powder and Pyrodex; nitrocellulose propellants, both single and double base
86.Knowledge of projectiles: design (ogive shape, base shape, cannelure types, forming processes); construction and composition (lead alloy compositions, jacketing materials, and styles, etc.)
87.Cartridge cases: design (i.e., rimfire, centerfire, Boxer/Berdan priming systems); compositions (copper, brass, steel, aluminum)
89.The history/development of ammunition components: cartridge naming system; alternate names; interchangeability
90.Knowledge of shotshell: design, construction, and nomenclature; shot sizes and composition (hardened lead, plated steel, etc.); wad design and types of filler (buffering) materials
92.Knowledge of ammunition components
98.Knowledge of internal ballistics: ignition, pressure, function of chamber design, chamber and cartridge dimensions, headspace considerations
24.Ability to determine the design of the lockwork (firing system) in firearms
26.Ability to determine the design type, method of operation and ignition of a submitted firearm
30.Ability to recognize the effect that firearms and ammunition manufacturing processes, the design of firearms, and design of firearms accessories have on markings imparted to bullets and casings and their interpretation
39.Ability to recognize, compare, and identify various ammunition types and components

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