Contact wounds are categorized as either hard contact (complete
contact) that normally leaves a pattern impression in the shape of the weapon
muzzle or loose contact (partial contact) that leaves a more irregular shape.
Contact wounds leave an abrasion collar that is normally obscured. The edges
of the contact wound and the bullet track are burned. If the gun is fired
through clothing, the surrounding fabric is also burned. The flame and smoke
may cause a sooty, grimy halo around the wound. When the muzzle of the gun
is held tightly against the skin, the bullet hole is not “tattooed” with powder
grains embedded in the surrounding skin like it is in intermediate-range
wounds. This is because most of the unburned powder and other explosive
products are blown right into the bullet track. The contact wound may also
show a bruise pattern from swelling gases blowing the skin back against the
muzzle of the gun. It may be shaped like the muzzle end of the gun, sights, or
extractor spring rod.