======+======================================================== |Firing on a target 1 m. high, the following percentages | of hits may be expected when the error in estimating | the range is-- Range.| 50 m. | 100 m. | 150 m. | 200 m. +-------+-----+-------+-----+-------+-----+-------+------ |Machine|Skir-|Machine|Skir-|Machine|Skir-|Machine|Skir- | guns. |mish-| guns. |mish-| guns. |mish-| guns. |mish- m. | | ers.| | ers.| | ers.| | ers. ------+-------+-----+-------+-----+-------+-----+-------+------ 500 | 27.5 | 16.0| 19.0 | 13.8| 7.0 | 11.7| 1.3 | 7.3 1000 | 9.2 | 6.8| 2.0 | 4.8| 0.2 | 2.7| -- | 1.0 1500 | 3.6 | 3.9| 0.2 | 1.8| -- | 0.5| -- | 0.1 2000 | 1.7 | 2.2| -- | 0.8| -- | 0.2| -- | -- ------+-------+-----+-------+-----+-------+-----+-------+------ From this it follows that the good qualities of the machine gun can be utilized to the fullest advantage only when the appropriate elevation is used. When this is not accurately known, the fire effect of the machine gun drops down to zero more quickly than that of a skirmish line. Where local conditions are at all favorable, the determination of the appropriate elevation is facilitated by observing the strike of the projectiles in “volley fire.” According to British firing tests, at ranges from 500-1000 yards an error of estimation of 100 yards, reduces the effect of the fire 50 per cent. According to firing tests 75% of all shots fired by a machine gun and body of infantry are distributed as follows: =====+==================+==================+==================== | Machine gun. | Detachment of |Errors of estimation | | infantry. | permissible for the At |Depth of 75% strip|Depth of 75% strip| machine gun. m. | m. | m. | m. -----+------------------+------------------+-------------------- 450 | 112 | 192 | 54 = 12 % 900 | 63 | 108 | 31 = 3.5% 1350 | 54 | 90 | 27 = 2 % 1800 | 67 | 140 | 31 = 1.8% -----+------------------+------------------+-------------------- It is clearly apparent that the permissible error of the range finder is smaller than the depth of the vertical dispersion strip covered by 75% of the bullets.