[2][3] The term originally came from the field of fire in front of forts (and similar defensive positions), cleared so there was no shelter for an approaching enemy.
The cone of fire describes a cone-like pattern formed by the projectiles with the gun not being moved.
The spread of rounds is due to vibration of the gun, tolerances of the ammunition and weapon, and the gunner's posture.
The cone of fire makes impact in an elliptical pattern called the beaten zone.
[8] The area that cannot be seen or aimed at within the gun's range (usually due to the terrain) is referred to as dead space.