The ammunition was a 5.65 millimeter (mm) (.223 caliber) fully jacketed rifle round. An investigation indicated that the wound was inflicted at a distance of 4 feet and the impact was essentially perpendicular to the head. General interpretation of gunshot wounds of the skull is based on certain principles, with some exceptions, of an entrance defect with internal beveling and an exit defect usually larger then the entrance and externally beveled. In this case differentiation of the entrance from the exit wound was straightforward, but the symmetrical distribution of external beveling around the entrance wound presented difficulties in interpretation. This artifact was attributed to blowback from pressure associated with temporary cavity formation. This case illustrates a pattern of external beveling associated with a perforating high-velocity gunshot wound. Consideration of this artifact in the interpretation of any gunshot wound of the head is warranted particularly in cases where soft tissues is absent or only bony fragments are available for examination. 3 figures and 9 references (Author abstract modified)