Firearms examiners are frequently called on to estimate the range from which a gunshot was fired. The distribution of gunshot residue on the target surface can be used for this determination. Gunshot residue consists of the following materials: (1) unburned propellant particles; (2) partially burned propellant particles; (3) soot from the combustion of propellant; (4) nitrates and nitrites from combustion of propellant; (5) particles of primer residue (oxides of lead, antimony, and barium); and (6) particles of bullet or bullet jacket. The terminology discussed in this article is frequently used to characterize ranges of fire based on the deposition of gunshot residue.
