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Possible Toolmarks

Home > Cartridge and Shotshell Examination > Identification Process > 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

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Courtesy of Nancy D. McCombs

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

Primer shearing marks caused by firing pin aperture

Courtesy of Nancy D. McCombs

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

Courtesy of Jack Dillon

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

Courtesy of Jack Dillon

Ejector marks Toolmarks produced on the head of a cartridge case, from contact with the ejector (generally at or near the rim)

Ejector marks

Courtesy of Jack Dillon

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

Courtesy of AFTE

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

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

Courtesy of Charles M. Clow

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