[1415]. Zone of effective fire. That portion of the ground which contains the best 75 per cent of the shots in the beaten zone, is called the zone of effective fire.
Effectiveness of Fire
[1416]. Factors involved. The effectiveness of fire depends upon these three factors:
- (1) The percentage of hits made;
- (2) The number of targets hit;
- (3) The time of execution.
That is to say, the effectiveness of fire is determined by the number of enemies disabled or targets hit in a given time.
[1417]. Percentage of hits. By the percentage of hits is meant the proportion of all the bullets fired that hit the targets. For example, if 1000 bullets are fired and 750 hit the targets, then the percentage of hits is 75.
The percentage of hits depends upon the dispersion, and this is influenced by the precision of the arm, the range, the visibility of the target, the atmospheric conditions, the training and instruction of the troops, and upon their physical and moral state at the time. In addition, the percentage of hits also depends upon the character of the ground as favoring ricochet hits, upon the correct estimation of the range and the proper designation of the target.
[1418]. Number of targets hit. The number of targets hit,—that is, the distribution of fire,—may be affected by varying degrees of visibility, as men instinctively choose the more conspicuous marks as aiming points. Under any circumstances, a poor distribution of the hits made will be due to an absence of proper instructions from the leaders; or, in other words, to poor control, or else to a want of understanding or lack of obedience on the part of the men.
[1419]. Time of execution. The time of execution is important in that the gaining of fire superiority is dependent less upon obtaining high percentages of hits than upon making an absolutely large number of hits in a unit of time. There is necessarily a limit to the rapidity of fire which, if exceeded, will result in some loss of accuracy. With targets of a fair degree of visibility, the following may be taken as standard rates of fire for troops who have been given suitable training in target practice:
| 200 yards | 10 shots per minute. | |
| 300 yards | ||
| 400 yards | ||
| 500 yards | 7.5 shots per minute. | |
| 600 yards | ||
| 700 yards | ||
| 800 yards | 5 shots per minute. | |
| 900 yards | ||
| 1,000 yards | ||
| Greater ranges, 3 shots per minute. | ||