Which mark indicates the firing pin impression?

• A. Ejector mark
• B. Drag mark
• C. Firing pin impression
• D. Primer residue

Answer: (C)

When a gun is fired, the firing pin strikes the primer and stamps its shape into the primer cup. That imprint is the firing pin impression—the mark you’d look for to identify the firing pin’s shape and potentially link a cartridge to a specific firearm. It’s a direct, physical imprint made by the firing pin itself.

This is different from ejector marks, which are created on the cartridge case when the case is expelled from the chamber; drag marks, which are scratches or wear from contact along movement surfaces, such as the bore or chamber; and primer residue, which consists of chemical particles left by the primer rather than a physical imprint. So the mark that indicates the firing pin impression is the imprint on the primer produced by the firing pin.