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).
Therefore, I developed a laser bore sight calculator that should get me much closer to zero at 100 yards. The objective here is to determine how far above the red laser dot I should adjust a scope for a 100 yard zero when bore sighting a rifle at 25 feet.There were two pieces of information I needed to know before performing these calculations.ecause the barrel is at an angle, as we move farther from the bore the closer together the two lines become. So, to properly set up my scope, I need to know how far above the red dot the scope must be adjusted for at 25 feet so the rifle can be zeroed at 100 yards (or at least close).