Skull showing keyhole gunshot trauma, about 1861-1865. Civil War Collection. Tangential entrance wounds into bone may produce "keyhole" defects with entrance and exit side-by-side, so that the arrangement of beveling can be used to determine the direction of fire. The term ballistic trauma refers to a form of physical trauma sustained from the discharge of arms or munitions. The most common forms of ballistic trauma stem from firearms used in armed conflicts, civilian sporting and recreational pursuits and criminal activity. Trauma a body wound or shock produced by sudden physical injury, as from violence or accident.