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).
1 Mil at 100 yards is 3.6 inches or 1/10th of what it is at 1,000 yards (1/10th of 36 inches). At 200, 300, 400, etc... it is 2/10, 3/10, 4/10, etc. So, if you know the size in inches of a target, you can tell how far it is by the number of mildot increments it spans in your scope.s a secondary function, the Mil Dots on the reticle can be set up as aiming points to compensate for holdover and wind drift. We'll address the range finding system first. Most Mil Dot scopes are set up to range find at 10X magnification.