Possible Toolmarks

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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	Mouseover the image and click to see the three marks highlighted. Click again to restart. 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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