Can be employed normally from or at a commanding position, or across a valley, but not when own troops and those of the enemy are on same plane.
Range of target must be accurate. If 1,000 yards or under, angles of sight to enemy and own troops must not be less than 30 minutes. If range is between 1,000 and 1,500 yards, the angle must not be less than 60 mins.
Overhead fire should not be used at 1,500 yards and over.
The following method of sighting can be used.—
Adjust backsight to correct range of target and lay gun on mark. If gun is nearer than 900 yards, raise sight by 400 yards, and if further than 900 yards, raise sight 250 yards.
The new line of sight gives safety angles.
When heads of own troops come into line of sight, cease fire, or continue to elevate gradually, keeping pace with advance.
Indirect Fire.
Firing from concealed positions at an auxiliary aiming mark.
A machine gun protractor, or graticules cut across the focal plane of prismatic glasses are most satisfactory. By this means indirect fire can be applied as easily as direct fire.