For the purpose of increasing fire power, the Japanese Army for
some time has been replacing the 6.5-mm (.256-cal.) weapons of its
infantry squad with 7.7-mm (.303-cal.) weapons. These include the
Model 99 (1939) 7.7-mm rifle and the Model 99 (1939) 7.7-mm light
machine gun. They have been designed to take the place of the
Model 38 (1905) 6.5-mm rifle, the Model 11 (1922) 6.5-mm light
machine gun, and the Model 96 (1936) 6.5-mm light machine gun.
Details of all these weapons except the Model 99 light machine gun
have been given in previous issues of the Intelligence Bulletin or
in other Military Intelligence Service publications. An Ordnance study of
the Model 99 rifle was published in Intelligence Bulletin, Vol. I,
No. 7. The Model 96 machine gun is described in TM 30-480 (as revised
Sept. 21, 1942), while the Model 38 rifle is described in TM 30-480 and
also in Intelligence Bulletin, Vol. I, No. 5.
The Model 99 rifle and light machine gun both fire Model 99
rimless 7.7-mm ammunition, which also is
adapted for firing in the Model 92 (1932) 7.7-mm heavy machine
gun. This latter weapon originally was made to fire only 7.7-mm Model 92
semi-rimless ammunition. The Model 99 weapons will not, in turn, fire
the semi-rimless ammunition, or any caliber .30 U. S. ammunition, or
any caliber .303 British ammunition. Although originally designed to
fire the semi-rimless ammunition, the Model 92 heavy machine gun has
a somewhat higher cyclic rate of fire with the Model 99 rimless ammunition.
A muzzle velocity between 2,250 and 2,300 feet per second was obtained in
firing the rimless Model 99 ammunition in the Model 99 rifle, the Model 99
light machine gun, and the Model 92 heavy machine gun.
On Attu whole units were found armed with the Model 99 rifle and light
machine gun. On Guadalcanal a small number of the new rifles and new light
machine guns were observed.
2. MODEL 99 RIFLE
The following notes on the Model 99 rifle supplement the information
about this weapon published in Intelligence Bulletin, Vol. I, No. 7:
The Model 99 rifle is known to the Japanese soldier as Kyu Kyu Tan Shoju
(99 short rifle). It is marked Kyu Kyu Shiki (Model 99) on top of the
receiver, just below the Imperial Seal. It is capable of delivering deadlier
and possibly more accurate fire than Model 38. However, the new rifle has a
pronounced muzzle flash, which is not the case with Model 38. Model 99 also
has a normal amount of recoil, which may affect the marksmanship of the
Japanese soldier, who is accustomed to the very slight recoil of Model 38.
Because of this difference in recoil, some prisoners of war have stated that
they prefer the old rifle.
The new weapon may be distinguished from the old by the following features:
a. It is 5 inches shorter.
b. A monopod mount, which is attached to the lower band and which can be
folded forward to catch on the stock when not in use.
c. A rubberized sling attached to swivels on the left side of the rifle
instead of to the bottom.
d. The slide of the rear sight has an arm extending to the left and one to
the right for use when firing at aircraft. The arms, which, when opened, extend
2 3/8 inches from the center of the rifle, are folded upward against the sight
during ground firing.
3. MODEL 99 LIGHT MACHINE GUN
The Model 99 light machine gun is a 7.7-mm version of the Model 96 light
machine gun. The two weapons are very similar in general appearance, and
the greatest care must be taken to distinguish them from each other. Many
parts are common to both guns.
Model 99 (see fig. 1) is known to the Japanese soldier as Kyu Kyu Keiki, and
is marked "Kyu Kyu Shiki" on top of the receiver.
|Figure 1a.—Japanese Model 99 Light Machine Gun (showing distinguishing rear monopod).|
|Figure 1b.—Japanese Model 99 Light Machine Gun (showing barrel partly withdrawn).|
b. Distinguishing Features
Model 99 may be distinguished from Model 96 by the following features:
(1) A heavy, adjustable monopod, which is attached to an extension
at the bottom of the butt plate.
(2) A trigger safety which is located on the left-hand side of
the trigger guard instead of on the right-hand side, as on Model 96.
(3) The method of locking the barrel to the receiver. On Model 99, the
barrel locking bolt, which holds the barrel in the receiver, is held on by a
heavy six-sided nut marked from 1 to 8. On Model 96 the barrel is retained in
the receiver by a locking swivel, which has an outside handle lying parallel
to the barrel.
(4) The flash hider of Model 99 screws onto the end of the barrel, which
is threaded to receive it. The flash hider of Model 96 locks onto the barrel
with a bayonet-type lock.
(5) The barrel of Model 99 is somewhat heavier than that of Model 96, but
both are of the same length.
(6) The magazine of Model 99 is about 1 inch longer and somewhat less curved
than that of Model 96.
Model 99 is considered a more effective weapon than Model 96, particularly
because of the support given by the adjustable monopod at the rear and its
heavier ammunition. It is believed that the effective range of Model 99 is
possibly 200 yards greater than that of Model 96. The former has a high
cyclic rate of fire, about 700 to 800 rounds per minute, in contrast to
an estimated cyclic rate of 550 rounds per minute for the Model 96.
1. In Intelligence Bulletin, Vol. I, No. 7, p. 5, par. 2,
line 4, change "semi-rimless" to "rimless."