Tag: gun

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Japanese

20 mm Aircraft Cannon Ho 5 (Browning Principle)

20 mm Aircraft Cannon Ho 5 (Browning Principle)

This weapon, an improvement on the 12.7 mm Japanese copy of the U.S. Cal. .50 aircraft machine gun, is a recoil-operated, disintegrating metallic link belt-fed, air-cooled, aircraft machine cannon. It is mounted as a fixed weapon and as such it is fired electrically by remote control.

The recoil mechanism consists of a metal cylinder into which is fitted a coil spring. Through the center of this extends a 5/16-inch rod which screws into a brass bushing. The rod extends through the spring follower which rests on the coil spring and is secured by two lock nuts. Buffering action takes place in the recoil direction only. There is no quick change barrel. Because of the weight of the bolt and the heavy recoil spring, a booster is used, this being found in the flash hider.

The gun has a high cyclic rate of fire, muzzle velocities of 2,304 f/s (A.P.), 2,430 f/s (H.E.), and a penetration performance of 7/8-inch homogenous plate at 20° at 200 yards; 1/2-inch at 20° at 580 yards. The maximum weight lifting capacity of the belt is 62 pounds.

The disassembly of the weapon is the same as the Browning Cal. .30 and Cal. .50 machine guns with a few minor exceptions. The Japanese weapon has no back plate latch. The back plate is held in place by two pins, one at the top, and one at the bottom.

SPECIFICATIONS

Caliber         20 mm (0.79 in.)
Weight w/accessories 104 11/16 lbs.
Weight w/o accessories 86 3/4 lbs.
Length (overall) 63 3/4 ins.
Sight radius
Principle of operation Recoil with muzzle cup
Feeding device Metal link belt type
Capacity of feeding device 100 rounds
Cooling system Air
Ammunition types A.P., H.E., Incendiary
Cyclic rate 950 r.p.m.
Type of sight Reflector
Weight of barrel 12 1/8 lbs.
Length of barrel 35.4 ins.
Length of rifling 31.5 ins.
Rifling
   Twist R.H.
   Form
   No. of grooves 8
   Depth of grooves
   Width of grooves
Chamber pressure
Muzzle velocity (A.P. Shot) 2,304 f/s
         (H.E. Shell) 2,430 f/s
Effective range 600 yds.

Japanese: p. 252 (June 1, 1945)

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Japanese

20 mm Aircraft Automatic Cannon, Model 99 Mk 1 Flexible

20 mm Aircraft Automatic Cannon, Model 99 Mk 1 Flexible

This weapon is an air-cooled, blowback-operated, Oerlikon type machine cannon. It operates on the same basic principle as all Oerlikon cannons of this type. The Japanese gun is a close copy of the Swiss gun, in that it is designed for full automatic fire only. The gun is manufactured in Japan on Swiss machinery. The above illustration shows the flexible version.

A significant feature is that the parts which are subjected to little wear, such as the grips, mounts, gunners’ shoulder rest, and other exterior parts are generally made of light weight metal.

This weapon is almost identical with other Model 99 (1939), 20 mm aircraft cannon reported to be used in the majority of Japanese planes, both as fixed guns in fighter craft, and as flexible guns in bombing planes. The weapon is fed from a drum type magazine. It is cocked or charged by manual means, and has no semiautomatic charger or rounds counter. The cocking handle is rotated to draw the recoiling parts to the rear and cock the gun for the first shot, the gun firing from an open bolt. Cocking operations for succeeding shots are performed by the blowback operation of the gun itself.

SPECIFICATIONS

Caliber         20 mm—0.87 ins.
Weight (without magazine) 62 lbs.
Weight of 60 rd. magaine (empty) 20 lbs.
Length (overall) 55 ins.
Length of barrel 30 ins.
No. of grooves 9; Uniform right hand twist
Width of grooves
Depth of grooves 0.022 in.
Width of lands
Muzzle velocity (shell) 1,930 f/s.
Cyclic rate 510 r.p.m.
Traverse Flexible aircraft
Length of recoil
Turns of cocking handle required to cock piece 11 1/2 ins.
Ammunition HE; HE with tracer; HE with self-destroying tracer; HE-I; AP; AP tracer; AP-HEI; Long burning tracer; Practice
Wt. of HE projectile 4.50 ozs.
Type of feed 60 rd. drum

Japanese: p. 251 (June 1, 1945)

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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

7.7 mm Paratrooper Rifles

Japanese 7.7 mm Paratrooper Rifles

Both of the weapons shown above are basically the same as the Japanese 7.7 mm standard infantry rifle, Model 99. They have been designed, however, to incorporate a takedown feature which enables them to be used by paratroop units. Manufactured at Nagoya Arsenal, they are manually-operated, bolt-action, magazine-fed, clip-loaded rifles.

The modified Model 99 differs from the basic weapon in the following respects: the barrel locking adaptor is secured to the receiver; the barrel is secured into the adaptor by interrupted screw threads; the bolt handle is detachable; and the stock is in two parts.

The Model 2, called “Teraju” by the Japanese, is of much better workmanship than the Modified Model 99. The barrel and front end are detached from the stock at the receiver ring. When taken down, the barrel section is 25 1/2 inches long; the stock 20 1/4inches. Total weight of the loaded weapon is 8.9 pounds. The takedown system is simple and sturdy. The barrel has a straight, unthreaded shank with a lug on the bottom. The shank fits into a socket in front of the receiver. A tapered locking key passes through the receiver (from right to left) and engages in front of the barrel lug. The key cannot be taken out completely, but may be withdrawn far enough to allow removal of the barrel. It is locked in place by screwing a nut on the right side into the receiver wall.

A spring actuated plunger located in the front end of the buttstock locks the barrel and forestock in position. This plunger must be retracted before the barrel can be rotated for takedown.

SPECIFICATIONS

Weight        8.9 lbs.
Length 44″
Principle of operation Manual, bolt-operated
Feeding device Clip
Capacity of feeding device 5 rounds
Ammunition types Model 99 rimless
Type of sight Front: inverted “V” blade on “T” base; Rear: leaf graduated from 328 to 1,640 yds. with aperature sight and aperture battle sight side arms for A.A. fire.
Weight of barrel
Length of barrel 25 7/8″
Length of rifling
Rifling:
   Twist Uniform, right hand; one turn in approx. 10 ins.
   Form Metford segmental
   No. of grooves 4
   Depth of grooves
   Width of grooves
Chamber pressure
Muzzle velocity 2,360 f/s
Maximum range 3,000 yds.
Effective range 600 yds.

Japanese: p. 212.1 (May 1, 1945)

Categories
Japanese

Triple Barrel Signal Pistol

Triple Barrel Signal Pistol

The triple barrel signal pistol, of naval design, is made of steel with black baked enamel finish and is equipped with plastic grips. It consists of three main parts: the barrel assembly, the firing mechanism housing, and the receiver. The barrels, which are slightly tapered and of the smooth bore type, can be fired only singly. The left barrel is marked with a red stripe, the top barrel with a white stripe, and the right barrel with a green stripe. The various kinds of ammunition used with the weapon (red, white, and green flares) must correspond with the color markings on the barrel. The weapon is carried in a leather holster.

The pistol is opened for loading by pulling forward on the spring-loaded barrel release lever and forcing downward on both ends of the pistol. Movement of the safety lever upward places the gun in the firing position; downward movement of the lever places the gun in the safe position. A counter-clockwise movement of the cocking lever cocks all three spring-loaded firing pins. Each firing pin has its own sear, and movement of the barrel selector lever to the desired stop directs the movement of the trigger to the proper sear, releasing the proper firing pin Double Barrel Signal Pistol and firing the round in the selected barrel. The three stops on the barrel selector lever are as follows: the left hand stop for the left hand barrel, the central stop for the top barrel, and the right hand stop for the right hand barrel.

The barrel assembly and firing mechanism recoil on the receiver during firing against the action of a recoil spring located in the receiver.

A double barrel version of this pistol is shown at the right.

SPECIFICATIONS

Weight of pistol       3 lbs., 11 ozs.
Length of barrel (approx.) 4 ins.
Bore diameter at muzzle 26.8 mm
Bore diameter at breech 28.4 mm
Types of ammunition used Red, white, & green flares

Japanese: p. 204.3 (August 1, 1945)

Categories
Japanese

8 mm Submachine Gun, Type 100 (1940)

8 mm Submachine Gun, Type 100 (1940)

The Japanese 8 mm submachine Gun, Type 100, is an automatic, air-cooled, magazine-fed, straight blowback-operated type, firing from an open bolt. Its basic design strongly resembles that of the German submachine guns. The weapon may be broken down into three main groups: a receiver which contains the bolt and driving spring, a barrel assembly, and a wooden stock assembly containing the trigger and trigger guard. A considerable amount of rough welding is used on the weapon; the front sight, bayonet lug, barrel lock, magazine well, driving spring guide, and trigger guard have all been attached to the rifle by this method. An unusual feature of the gun is a replaceable firing pin which screws into the face of the bolt.

The weapon has a high cyclic rate of fire, estimated between 800 and 1,000 rounds per minute.

It differs from the Type 100 (1940) Paratrooper’s rifle, described on page 204.1, in the following respects: it does not have a folding stock; a standard bayonet can be mounted directly on barrel and barrel jacket; and the rear sight is fixed rather than of the sliding ramp type.

SPECIFICATIONS

Caliber      8 mm (.315 in.)
Weight with sling and magazine9 lbs., 2 oz.
Weight of magazine9 oz.
Length (overall)36 ins.
Sight radius
Principle of operationStraight blowback
Feeding deviceCurved box magazine
Capacity of feeding device30 rounds
Cooling systemAir
Ammunition types8 mm pistol
Rate of fire (cyclic)800-1,000 rds. per min. (est.)
Type of sight—Front:Inverted “V”
                      Rear:“V” with small peep additional.
Weight of barrel
Length of barrel9 3/16 ins.
Length of rifling8.3 ins.
Rifling:
   TwistR.H .
   Form
   No. of grooves6
Muzzle velocity1,050 f/s
Maximum range
Effective range

Japanese: p. 204.2 (August 1, 1945)

Categories
Japanese

140 mm Seacoast Gun Type 3

140 mm Seacoast Gun Type 3 -- Japanese, WWII

It is believed that this naval coast defense weapon was designed primarily for use against ships, as the fuzes used with the gun’s ammunition are not sensitive enough to function satisfactorily upon impact with soft ground. This gun uses separate loading ammunition, and has a standard type mushroom head obturator. The breechblock is the horizontal swinging, interrupted screw type, having three threaded segments with two step threads. A hydropneumatic recoil mechanism is located above the barrel.

A naval pedestal type mount is used. Strips of iron fastened to and radiating from the pedestal are buried in the ground to insure stability. The piece is sometimes fitted in a casemate, the front and sides of which are cast in one piece. The top is rolled plate. A mantlet is fitted to the gun on the inside of the casemate. Gun and casemate are rotated manually, as no power system is provided.

No fire control equipment, with the exception of a telescopic sight mount, was recovered with the gun, and it is believed that the piece is fired by direct laying.

SPECIFICATIONS

Caliber         140 mm (5.5 ins.)
Weight (firing position)
Length (overall) 23 ft., 8 ins.
Length (firing position)
Height (firing position)
Width (overall)
Length of tube 22 ft., 10 1/2 ins.
Length of rifling 19 ft., 3 1/2 ins.
No. of grooves 42
Width of grooves
Depth of grooves 0.051 in.
Width of lands
Muzzle velocity (shell) 850 meters (2,789 ft.) per sec.
from range disc on gun
Max. range (horizontal) 17,000 meters (18,598 yds.)
from range disc on gun
Rate of fire
Traverse 360°
Elevation 30°
Depression -7°
Length of recoil
Ammunition
Wt. of projectile (H.E.) Common         83.8 lbs.

Japanese: p. 114.6 (August 1, 1945)

Categories
Japanese

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10 (Japanese WWII)

The Japanese Type 10 dual purpose gun has a 45-caliber barrel of monobloc construction with uniform right hand rifling. A long, narrow rectangular projection on the bottom of the barrel slides in a groove in the sleeve type cradle, preventing the barrel from rotating. The bearing surface for recoil being the machined barrel surface. The cradle is mounted on a pedestal mount which permits a traverse of 360 degrees.

The elevating handwheel is on the right side of the mount, while the traversing handwheel is on the left. An auxiliary handwheel on the left side permits the piece to be elevated and traversed by the gunner. To compensate for muzzle preponderance, a spring pusher type equilibrator is used. The gun is well balanced, and exceptionally easy to elevate. The recoil mechanism is a hydrospring type, the two outside cylinders housing the counterrecoil springs, and the center cylinder the hydraulic mechanism. A semiautomatic horizontal sliding breechblock is used.

The mount is of riveted construction.

SPECIFICATIONS

Caliber       120 mm (4.7 ins.)
Weight (firing position) 6,500 lbs.
Length (gun and mount) 19 ft., 6 1/2 ins.
Length (firing position)
Height (gun and mount) 7 ft., 8 1/2 ins.
Height (firing position)
Width (gun and mount) 7 ft., 1 in.
Length of tube 17 ft., 1 1/2 ins.
Length of rifling 14 ft., 9 1/2 ins.
Length, of chamber 29.5 ins.
No. of lands 34
Width of grooves 1/4 in.
De-th of grooves .050 in.
Width of lands 1/8 in.
Muzzle velocity (shell) 2,700 f/s
Max. range (horizontal) 17,000 yds.
Max. range (vertical) 32,800 ft. (fuze)
Rate of fire 10-12 rds.
Traverse 360°
Elevation 75°
Depression 10°
Length of recoil 19.3 ins.
Ammunition H.E. shrapnel; H.E. phosphorus
Wt. of projectile 45.75 lbs.

Japanese: p. 114.5 (August 1, 1945)

Categories
Japanese

120 mm, 45 Caliber, 11 Year Type Gun

Japanese 120mm 45 Caliber 11 Year Type Gun

This gun is a naval coast defense weapon manufactured at Sasebo Arsenal. It uses semi-fixed ammunition. The barrel is of built-up construction with uniform right hand twist rifling. A manually operated, horizontal sliding block breech mechanism is used. It is unusual in that the block does not pass all the way across the rectangular breech ring. The rear of the breech ring is cut in a keyhole shape. The operator of the elevation handwheel may fire the gun by means of a lever mechanism, or it may be fired by a lanyard attached to the right side of the breechblock.

The recoil system comprises three cylinders, two located above and one below the barrel.

The mount consists of a rectangular upper carriage which is mounted on a pedestal normally embedded in a solid foundation. A traversing scale is located on the pedestal. The traversing handwheel is in a horizontal position with the vertical shaft engaging a series of gears in the base mount. Platforms attached to the upper pedestal are provided for the gun layers and move in traverse with the gun.

Fire control equipment is of the usual Japanese naval coast defense gun type.

SPECIFICATIONS

Caliber      120 mm (4.72 ins.)
Weight (traveling position)
Weight (firing position)
Length of gun (overall)18 ft., 3 1/4 ins.
Length of tube 17 ft., 3 3/4 ins.
Height of gun 6 ft., 11 ins.
Height (firing position)
Width (overall)
Length of rifling 14 ft., 8 1/2 ins.
No. of lands34
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (H.E. shell)2,700 f/s
Max. range (horizontal)
Max. range (vertical)
Rate of fire
Traverse360°
Elevation50°
Depression10°
Length of recoil
AmmunitionH.E.
Wt. of projectile (H.E.)44.75 lbs.

Japanese: p. 114.4 (August 1, 1945)