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Firearms Examiner Training

Possible Toolmarks

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Possible Toolmarks

The marks produced on cartridge cases and shotshell cases during the cycle of fire may include:

Toolmark Description Image
Firing pin impressions Indentation of the primer of a centerfire cartridge case or the rim of a rimfire cartridge case when struck by the firing pin

 

Firing pin drag marks Striated toolmarks produced when a projecting firing pin contacts a cartridge or shotshell during extraction and ejection
Breech face marks Negative impression of the breech face of the firearm found on the head of the cartridge case and/or primer after firing
Primer shearing marks Striated toolmarks caused by the rough margins of a firing pin hole (aperture) scraping the primer metal during unlocking of the breech of a firearm
shearing marks caused by firing pin aperture
Primer shearing marks caused by firing pin aperture
Courtesy of Nancy D. McCombs (see reuse policy).
Chamber marks Individual microscopic marks placed on a cartridge case by the chamber wall as a result of chambering, expansion during firing or extraction
Chamber marks
Chamber marks
Courtesy of Jack Dillon (see reuse policy).
Extractor marks Striated toolmarks produced on a cartridge or cartridge case from the operation of an extractor (usually found on or just ahead of the rim)
Extractor marks
Extractor marks
Courtesy of Jack Dillon (see reuse policy).
Ejector marks Toolmarks produced on the head of a cartridge case, from contact with the ejector (generally at or near the rim)
Ejector marks
Ejector marks
Courtesy of Jack Dillon (see reuse policy).
Anvil marks Microscopic marks impressed on the forward face of the rim of a rimfire cartridge case as it is forced or compressed against the breech end of the chamber by the firing pin
Anvil marks
Anvil marks
Courtesy of AFTE (see reuse policy).
Ejection port marks Striated marks produced by hard contact between the ejection port of a firearm and a rapidly moving ejected cartridge case
Ejection port mark
Ejection port mark
National Institute of Justice (NIJ) (see reuse policy).
Magazine marks Striated marks produced on the periphery of a cartridge as it moves from the lips of a magazine towards the chamber during feeding
Magazine lip marks
Magazine lip marks
Courtesy of Charles M. Clow (see reuse policy).

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