a. General
Actual contact with the enemy tends to dissipate the illusion of his power. This
illusion is often present in the mind of a soldier until he has been in action. The
following observations on Japanese artillery combat in the jungles of southwest
Burma, drawn from a British officer's report, points up the foregoing conclusion.
* * *
The outstanding fact about Japanese artillery in the latter part of the
campaign was its inactivity. For the 30,000 shells fired at the enemy, he replied
to this regiment with only some 400 rounds. These were mostly fired by 75-mm
mountain guns. Moreover, the firing of his guns was such an event that regimental
headquarters was always snowed under with requests for sound bearings, times
of flight, etc., within a few moments of commencement of firing. To meet such
requests, all compasses in the supported infantry brigade should always be
calibrated by regimental headquarters as soon as possible. In some cases
strenuous efforts on the part of the artillery were necessary to convince infantry
battalions of the necessity of adding their own observations to those of the
artillery. In other cases, infantry battalions seemed poorly equipped to do so.
Based on the many reports received, a fair amount of data was made
available; this applied equally to the 75-mm mountain and 75-mm regiment
gun, but not to the 70-mm battalion gun, of which little is known, apart from
fact that an artillery prisoner of war said it was useless.
b. Specific Observations
(1) Tactical. The gun is located often singly, with complete flash cover,
(near regimental headquarters if a regimental gun), well off the beaten track.
Most difficult to spot, it will always move if possible after firing. Usually its
positions were out of range of the 3.7 howitzers, chosen if possible for the
employment of extreme range.
(2) Technical. Registration will be carried out for some time before any
particular target is engaged. Then usually only two ranging rounds suffice; however,
more are sometimes required.
(3) The Gun. The Japanese piece was very accurate, with a 100% zone
of about 50 yards at 7,000 yards using 50 rounds; crater, eighteen inches
diameter, three inches deep; fragmentation, normal; concussion effect very small.
The delay action, graze fuze, burst on small branches of trees. The angle of fall
at 7,000 yards was about 38 degrees; the general effect of the shell was very
small -- the sound of the burst of this gun was less than that of a 3.7 howitzer
but quite like our own 2-inch mortar, while the rate of fire was very fast, up to
10 rounds per minute.
(4) Deception. One habit of the Japanese was noticed early in the campaign
and frequently encountered afterwards. While our own artillery was firing on a
close-in target, he opened up with his mortars on our own front line, timing his
fire so that the burst of our shells and his bombs should be as nearly simultaneous
as possible. Not only was our own attention apt to be distracted, thereby reducing
the chances of his mortars being located, but also he obviously hoped (and on two
occasions he temporarily succeeded) in making our own infantry believe that their
casualties were being caused by short rounds from our own guns. [A similar
deception has been reported from the North African operations.]