Machine-Gun Tactics

Name: Machine-Gun Tactics
Author: Applin, R. V. K. (Reginald Vincent Kempenfeldt)

Applin, R. V. K. (Reginald Vincent Kempenfeldt)

Machine guns

There are two methods of laying the gun. (1) By observation of
fire. (2) By quadrant elevation. The first method has been already
described, and the second must be done by using the following
table in conjunction with an instrument for elevating the gun at
the required angle; but it must be remembered that each gun will
require adjusting to its own angle of elevation to suit its known
error at each range. Thus a gun which is known to require sighting
at 900 yards when firing at 1,000 should receive 1° 10½ and not 1°
25½. When proper instruments are not obtainable, very fair results
may be obtained by using an ordinary clinometer. The necessary
allowance for the height the gun is above the target must be made,
or, in other words, the angle of sight as shown by the clinometer
must be deducted from the quadrant elevation given on the gun.

[Illustration: DIAGRAM IV

TO SHOW METHOD OF LAYING BY AIMING POSTS

  aa. Aiming Posts (about 15^x apart and some distance in front
      of gun.)

  ttt. Targets.]


TABLE OF ELEVATION FOR MAXIM ·303 USING AMMUNITION GIVING 2,000 F.S.

  ------------+---------------------------
     Range.   | Angles of elevation on the
              |          Maxim gun.
  ------------+---------------------------
    200 yards |         0   4·0  0  1
    300   ”   |         0   9·5   ”
    400   ”   |         0  17·0   ”
    500   ”   |         0  25·5   ”
    600   ”   |         0  35·5   ”
    700   ”   |         0  45·5   ”
    800   ”   |         0  57·5   ”
    900   ”   |         1  10·5   ”
  1,000   ”   |         1  25·5   ”
  1,100   ”   |         1  41·5   ”
  1,200   ”   |         1  57·5   ”
  1,300   ”   |         2  16·5   ”
  1,400   ”   |         2  37·5   ”
  1,500   ”   |         2  59·5   ”
  1,600   ”   |         3  22·5   ”
  1,700   ”   |         3  47·5   ”
  1,800   ”   |         4  14·5   ”
  1,900   ”   |         4  43·5   ”
  2,000   ”   |         5  14·5   ”
  2,100   ”   |         5  42·0   ”
  2,200   ”   |         6  22·0   ”
  2,300   ”   |         6  59·0   ”
  2,400   ”   |         7  40·0   ”
  2,500   ”   |         8  25·0   ”
  2,600   ”   |         9  16·0   ”
  2,700   ”   |        10  18·0   ”
  2,800   ”   |        11  18·0   ”
  ------------+---------------------------

What is required is the angle of _quadrant elevation_ to be put on
the gun in order that the shots may strike the target at a known
range. From range table obtain _angle of tangent elevation_; now
if the target is _below_ the guns we must _subtract_ the angle of
sight (_m_), if the target is _above_ the guns we must _add_ the
angle of sight (_m_) to obtain correct angle of quadrant elevation.

  _To obtain angle of sight m_

(1) When target is visible from the immediate vicinity of guns the
angle may be measured by pocket clinometer or other mechanical
means; or, if heights can be obtained from a contoured map, from
the formula:

  _m_ = (_h_ × 1146)/R

Public-domain text, read in full here on John Shaqi.

Machine-Gun Tactics

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