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).
Shooting accuracy distance 1000 metres. Franz Dorfner from Vienna achieved this dispersion pattern in October 2012, radius 82 mm, 5 shots, distance 1000 m, with his Fortmeier-gun Take Down M 2002 with LOTHAR WALTHER-barrel cal. 408 Chey Tac (barrel length 900 m), cartridge Mayerl Styria homogen copper .408-400 grs. Shooting accuracy of cal. 6 mm PPC. This dispersion pattern was shot by Manfred Schmitt on 28.08.2011 with a LOTHAR WALTHER-barrel cal. 6 mm PPC: 5 shots, distance 100 m, dispersion radius 2,5 mm. There is placed a 1-cent coin beside the shots for comparison.