1. GENERAL

The Japanese have put into use a new service rifle (see fig. 1), which is in many ways similar in operation, functioning, and general design to their Meiji 38th-year pattern (1905) rifle, except for a shorter barrel, larger caliber, and improvements in the rear sight. The new weapon is known as the 99th-year pattern (1939) short rifle.

The caliber of the Japanese weapon is 7.7 mm. (.303), the same caliber as the Lee-Enfield rifle and the Bren light machine gun, both standard weapons in the British Army. However, the ammunition is semi-rimless and not rimmed like the British .303 Mk. VII.

One of the new rifles, captured on Guadalcanal, was examined by a U.S. Army Ordnance officer. He described the rifle as a manually operated, air-cooled, shoulder weapon. It is loaded by means of a clip, which contains 5 rounds of ammunition similar to that of our M1903 rifle. However, U.S. caliber .30 ammunition will not fit into the firing chamber of the Japanese weapon, because the distance from the base to the tapered shoulder of the cartridge case is sufficient to prevent the bolt from closing. In addition, our ammunition is too long to fit in the magazine. British caliber .303 ammunition will fit in the firing chamber, but the bolt will not close because the base of the cartridge case is too large in diameter and has too large a rim to fit in the recess of the bolt. Four rounds of the British ammunition will fit into the magazine.

Figure 1. New Japanese Rifle; (a) Right Side, (b) Left Side.

The Japanese rifle is equipped with a cleaning rod, which is carried in a hole in the stock, just under the barrel. The rod is held secure by a catch.

A sling, made of rubberized canvas, is attached to swivels on the lower band and stock on the left side of the rifle.

The rifle has a monopod attached to the lower band. While not in use, the pod can be rotated forward to catch on the stock. This pod is about 12 inches long from the center line of the bore, and it appears to be too long for use in the prone position.

The bolt mechanism of the rifle, like that of the older 6.5-mm Japanese rifle, is covered by a semicircular cover of sheet metal that slides with the bolt in loading and extracting ammunition. The purpose of this cover probably is to keep dirt from fouling the mechanism. The rifle is not provided with a cut-off for firing single shots.

Although distribution of the new rifle may have started as early as July, 1942, it is reasonably certain that a large majority of Japanese infantry troops are still equipped with the old 6.5-mm (.256 caliber) rifle, the Meiji 38th-year pattern (1905), or with its carbine form. This old model has not been changed since 1905.¹

2. TABLE OF CHARACTERISTICS

Weight of rifle (unloaded) with sling		8.8 lbs.
Magazine capacity		5 rounds
Over-all length		44 in.
Length of barrel		25 1/2 in.
Length of barrel and receiver		32 3/4 in.
Rifling (right-hand twist) one turn in (estimated same as U.S. M1903)		10 in.
Grooves in barrel		No. 4
Depth of grooves		Estimated twice that of U.S. M1903 rifle
Caliber of bore (measured)		.303 in.
Trigger pull		9 lbs.
Range on rear-sight leaf		300 to 1,500 meters (328 to 1,640 yds).
Peep-sight opening		1/8 in.

3. DESCRIPTION OF COMPONENT PARTS

In general, the new rifle is composed of four main groups of assemblies and parts. They are described as follows:

a. Barrel Group

The barrel, approximately 25 1/2 inches long, is threaded into the receiver in a manner similar to the method used in U.S. rifles. An alignment mark is provided for assembling the barrel and receiver together. The bore has four right-hand lands and grooves with a twist (approximately the same as the M1903 rifle of one turn per 10 inches. The grooves are cut much deeper than those of U.S. rifles.

b. Receiver Group

With few exceptions, the receiver is constructed much like that of the Japanese 38th-year pattern rifle. A bolt stop is provided at the left rear part of the receiver by merely utilizing a piece of metal that swings a lug clear of the bolt when it is withdrawn from the rifle. The ejector is hinged in the bolt stop and operates in principle like that of the U.S. rifle M1917. (See TM which describes the U.S. caliber .30 M1917 rifle.) The rear of the receiver has a slot cut for a lug in the safety. The receiver has grooves cut near the firing chamber for the locking lugs of the bolt, in a manner nearly identical to those in U.S. rifles. The grooves do not appear to be tapered, providing for "slow extraction" of fired cartridge cases; this is a point considered important in the design of U.S. rifles. A gas-escape vent hole 3/16 inch in diameter is provided in the top of the receiver just in rear of the firing chamber.

c. Front Sight

The front sight is practically identical with that of U.S. caliber .30 M1917 rifle (see TM No. 1917, which describes this U.S. rifle). An alignment mark is provided for matching the front sight with the front-sight carrier.

d. Rear Sight

The rear sight of the rifle is located approximately in the center of the rifle. The sight is of the folding-leaf type with a regular peep-sight and a battle peep-sight; each has an opening of 1/8-inch diameter. The rear-sight leaf has calibrated notches for ranges of 300 to 1,500 meters (328 to 1,640 yds), inclusive. The sight has no means provided for correcting range or drift. The slide on the sight is equipped with two arms (right and left) that can be swung out 2 3/8 inches from the center of the rifle and are probably used for antiaircraft fire. The remainder of the parts of this sight are similar to those of the U.S. caliber .30 M1917 rifle, shown in FM 23-6.

e. Operating Mechanism Group

The operating mechanism consists essentially of the bolt, extractor, striker, mainspring, and safety. These parts, except for the safety, are very similar to those on the U. S. caliber .30 M1937 rifle. The safety fits into the end of the bolt and locks the bolt parts together by means of a lug on the safety, which engages in a slot in the striker, and a lug on the bolt which engages in a slot in the safety. The safety is applied when pushed forward about %-inch and rotated approximately 15 degrees clockwise, engaging a lug on the safety with a circular groove in the receiver. This action locks the bolt in the receiver and also locks the striker to the safety. The trigger is not locked when the safety is applied.

f. Trigger-Mechanism Group

The parts and principle of operation of the trigger mechanism are practically identical with those of the U.S. caliber .30 M1917 rifle. The trigger is not designed for initial slack at the start of the pull, but moves with a steady resistance. The mechanism requires a very high trigger pull of 9 pounds before firing, compared to 3 1/2 to 5 1/5 pounds pull in the U.S. M1903 rifle. As the sear is released due to a camming action of the trigger on the receiver, a safety stud on the forward end of the sear is shoved into a groove in the bolt to act as a lock when a round is fired.

g. Magazine Group

The magazine group consists essentially of the trigger guard, magazine, follower, magazine spring, and floor plate; parts similar to these are shown in FM 23-6 for the U.S. caliber .30 M1917 rifle. The floor plate differs in design in that it is hinged to the forward part of the trigger guard and held in position by a catch located in front of the trigger. When the catch is released, the magazine spring and follower fly out with the floor plate. This feature of the Japanese rifle is very good.

h. Stock and Hand-Guard Group

The stock of the Japanese rifle is made in two pieces and fastened together by a dove-tailed joint in the butt of the stock--a method probably adopted to conserve material. No provision is made in the butt of the stock for any accessories. The receiver and the trigger guard are held firmly to the stock by three screws. The butt of the stock is covered by a butt plate. The hand guard is constructed in one piece and held in place by the upper and lower bands. The wood portion of the rifle appears to be made from wood similar to the U.S. white walnut or a wood softer than the black-walnut stocks used on U.S. rifles.

¹ For details of Meiji 38th-year pattern rifle, see Intelligence Bulletin, No. 5, p. 53, or TM 30-480, p. 92.