The single most examined comparison in firearm injuries is distinguishing the entry wound from the exit wound. Master this table first, then learn the special collars that mark an entry wound.
Entry Wound vs Exit Wound
| Feature | Entry Wound | Exit Wound |
|---|---|---|
| Size | Usually smaller | Usually larger |
| Shape | Circular or oval | Irregular, slit-like or stellate |
| Margins | Inverted | Everted |
| Abrasion collar | Present | Absent |
| Grease/dirt collar | Present | Absent |
| Blackening | May be present in close-range firing | Absent |
| Tattooing | May be present in close-range firing | Absent |
| Burning/singeing | May be present in close-range firing | Absent |
| Bleeding | Less external bleeding | More external bleeding |
| Bone injury | Internal beveling in skull | External beveling in skull |
| Clothing fibres | Driven inward into wound track | May protrude outward |
| Bullet recovery | Bullet usually not present | Bullet has usually exited |
| Identification | Usually easier | Sometimes difficult |