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).
Many agencies are opting for this cartridge as a result of its long range ballistics. The .308 Win. has a maximum effective range of about 800 yards. While this is certainly more than enough for most law enforcement scenarios (law enforcement snipers rarely have to engage targets at more than 100 yards), the .300 Win.Mag.any agencies are opting for this cartridge as a result of its long range ballistics. The .308 Win. has a maximum effective range of about 800 yards. While this is certainly more than enough for most law enforcement scenarios (law enforcement snipers rarely have to engage targets at more than 100 yards), the .300 Win.