Bullets of equal wounding potential may produce wounds of very different severity. Wounding is an interaction between the missile and the tissue. When attempting to predict wound severity, focusing on missile velocity while forgetting either the properties of the tissue wounded or the missile’s mass and construction leads to very poor predictions. Fortunately, all the poor predictions commonly made are of little consequence as it is the condition of the patient, not the type of firearm or missile used, that determines the treatment needed. Tissue crush and tissue stretch by displacement (temporary cavitation) are the only wounding mechanisms of missiles. Tissue stretch is tolerated very differently by different tissues. Missiles can embolize. Missile type, direction of fire, and order of shots can sometimes be assessed radiologically. Lead bullets or fragements in joints cause lead synovitis, mechanical arthritis, and sometimes lead poisoning. When possible, they should be removed. For shotgun wounds, steel shot may be ferromagnetic and is important to recognize prior to magnetic resonance imaging. Steel shot stays round and does not deform like lead shot. The "billiard ball effect" may compromise assessment of range unless correlated with skin physical examination.