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Japanese

Double Barrel Flexible Aircraft Machine Guns Model 100 and Model 1

Double Barrel Flexible Aircraft Machine Guns Model 100 and Model 1

These two weapons which are very similar offer the advantage of two guns being mounted in the space occupied by one gun of normal size, thus saving weight in the gun and mount, and space in the plane. A small ammunition supply making frequent magazine changes necessary is a disadvantage partially for the advantages of the double barrel principle.

The operating mechanism for both barrels is housed in a single receiver. This is a single forging, milled to house the two separate actions. The magazine opening is cut out of the top of the receiver, the ejection slot out of the bottom. Each action has its own back plate. The gas piston group resembles the Bren light machine gun in design. The bolt is a steel forging well machined. The gas cylinder tube is constructed of seamless steel tubing and is threaded to the receiver at the rear. The trigger assembly is made up of two separate sear assemblies riveted to the pistol grip framework. Two pistol grips are located about 6 inches apart; the sears are connected to a horizontal trigger bar mounting a trigger on either end. Both guns may be fired by depressing either trigger. The magazine is the saddle-drum type. Each side holds 50 rounds and feeds one gun. Each side has its own spring so that, in the event of a jam affecting one barrel, the other gun may continue to fire.

The Model 1 (1941) gun appears to be basically the same weapon as the earlier model, Model 100 (1940) which is shown at the bottom of the illustration. The Type 1 gun shown at the top of the picture has a head or shoulder rest attached to the gun. This rest is made of wood and canvas and is attached to the gun with steel frames. The specifications were secured from the earlier weapon.

SPECIFICATIONS

Caliber         7.92 mm
Weight of gun 36 lbs.
Length (overall) 37.5 ins.
Length of receiver 16.25 ins.
Length of barrel 24.5 ins.
Length of rifling 22.37 ins.
Diameter of bore—
   across lands 0.310 in.
   across grooves 0.313 in.
Number of lands 4
Width of lands 0.0781 in.
Width of grooves 0.1718 in.
Depth of grooves 0.003 in.
Twist of rifling Uniform R.H.
Pitch of rifling 7° (approx.)
Type of operation Gas
Type of fire Automatic only
Type of feed Magazine, saddle-drum type
Capacity of magazine 100 rounds
Weight of magazine empty 7 3/4 lbs.
Weight of magazine filled 13 3/4 lbs.
Ammunition A.P.—Incendiary
Rate of fire (estimated) 400-600 r.p.m.
Range 250 to 350 meters

Japanese: p. 216.1 (March 1, 1945)

Categories
Japanese

7.7 mm Heavy Machine Gun Model 01 (1941)

Japanese 7.7 mm Heavy Machine Gun Model 01 (1941)

This gun incorporates most of the features of the Model 92 Heavy Machine Gun, but is smaller and lighter. A total weight saving of 41 pounds in the gun and tripod mount is achieved. The barrel of the new gun is considerably shorter than that of the Model 92; therefore, the muzzle velocity is probably lower.

Both guns feed from 30-round strips, but the 01 (1941) uses rimless ammunition. The new gun incorporates the following modifications:

The barrel of the Model 01 may be quickly removed. The flash hider is screwed onto the muzzle, eliminating the knurled locking collar used on the older gun. The gas regulating system is similar to that of the 7.7 mm Model 99 (1939) Light Machine Gun. A smaller oil reservoir is used. A new method of attaching the ejection port cover allows easier access to the receiver which should aid in clearing stoppages. Minor changes in the metal sights have been made. A crank-shaped safety is fitted through the top of the sear housing with its handle at the left rear of the receiver. The new tripod is lighter and has different type spades. It also has a different mechanism for elevating the pintle support above the tripod base. The receiver of the Model 01 is lighter.

SPECIFICATIONS

Weight (total)        69.9 lbs.
Weight (without mount) 34 lbs., 2 ozs.
Weight of mount 37 lbs.
Weight of tripod 36.3 lbs.
Length (overall w/flash hider) 42 3/8 ins.
Length (overall w/o flash hider) 38 ins.
Sight radius
Principle of operation Gas, full-automatic
Feeding device Metal strips
Capacity of feeding device 30 rounds
Cooling system
Ammunition types Model 92 ball, A.P. and tracer (rimless)
Rate of fire (estimated) 450-500 r.p.m. cyclic
200-250 r.p.m. effective
Type of sight Rear, calibrated from 100 to 2,200 meters.
Weight of barrel 11 lbs., 6 ozs.
Length of barrel 23 3/16 ins.
Length of rifling 22 ins.
Rifling
   Twist R.H.
   Form
   No. of lands 8
   No. of grooves
   Depth of grooves
   Width of grooves
Muzzle velocity
Maximum range
Effective range
Type of mount Tripod
Elevation
Traverse (total—on arc) 45°

Japanese: p. 214.2 (June 1, 1945)

Categories
Japanese

Armored Tracked Personnel Carrier

Armored-tracked Personnel Carrier: Type 1 Ho-Ki

This vehicle serves as an artillery prime mover and as a personnel carrier for 24 men. It appears to be of recent manufacture, and its first known appearance in combat was during the Leyte campaign in the Philippines.

It is a full-tracked vehicle armored with 1/4-inch plate throughout. The engine which is located at the right front of the body is a 6-cylinder, in-line, valve-in-head, air-cooled diesel of a type similar to those used in the Model 2595 light tank and the combination prime mover and wrecker. Two fuel tanks provide an estimated total capacity of 50 to 60 gallons.

The tracks and suspension are of the conventional Japanese design, using dual bogie wheels and a steel center guide track. The four bogie wheels, apparently identical with those on the Model 2595 light tank, are mounted on bell cranks and are sprung by horizontal coil springs which are inclosed within the body armor with only the bogie arms exposed. There are two return rollers. The track is driven from the rear. A clutch and brake steering system is used. The transmission provides four speeds forward and one reverse. A high and low transfer case is also provided.

A mount for a 7.7 mm machine gun is located on the left front of the driver’s compartment. The vehicle does not mount a winch, but is provided with a spring mounted towing pintle for use as a prime mover. It has a capacity of from 2 to 3 tons if used as a cargo carrier. Maximum speed is reported as approximately 35 miles per hour, with exceptionally good cross-country performance due to the amount of track area in contact with the ground in relation to the weight of the vehicle.

SPECIFICATIONS

Weight
Length (overall)       15 ft., 9 ins.
Width (overall) 6 ft., 8 ins.
Height
Ground clearance
Tread centers
Ground contact 9 ft., 10 ins.
Width of track 10 ins.
Pitch of track 3-13/16 ins.
Track links 125
Fording depth
Theoretical radius of action
     Roads
     Cross-country
Speed (maximum) 35 m.p.h.
Armor (reported) 1/4 in.
Armament 7.7 mm machine gun
Ammunition (Rds.)
Engine 6-cylinder, in-line, valve-in-head, diesel.
Transmission 4 speeds forward, 1 reverse; high and low range.
Steering Clutch and brake system
Seating capacity 24

Japanese: p. 18.3 (May 1, 1945)