Subcutaneous emphysema is often found in car accident victims because of the force of the crash. Chest trauma, a major cause of subcutaneous emphysema, can cause air to enter the skin of the chest wall from the neck or lung. When the pleural membranes are punctured, as occurs in penetrating trauma of the chest, air may travel from the lung to the muscles and subcutaneous tissue of the chest wall.
Both the Army and the Marine Corps teach that the maximum effective range of the M16A2/A3/A4 is 500 meters on a point target (individual enemy) and 800 meters on an area target (i.e. troops in the open).
Range: Any attack at more than this distance is penalized for range. Beyond this range, the attack takes a cumulative â2 penalty for each full range increment (or fraction thereof) of distance to the target. For example, a dagger (with a range of 10 feet) thrown at a target that is 25 feet away would incur a â4 penalty. A thrown weapon has a maximum range of five range increments.