Monthly Archive for September, 2009

6.5 mm Sniper’s Rifle Model 97 (1937)

Japanese 6.5 mm Sniper's Rifle Model 97 (1937)

The Japanese 6.5 mm Sniper’s Rifle, Model 97, is a manually operated, bolt-action, air-cooled, shoulder weapon similar to the Model 38 (1905) 6.5 mm rifle except for its monopod, turned-down bolt handle, and telescopic sight. The telescopic sight is attached to the left hand side of the receiver by means of a dove-tailed base. It is a fixed focus type of 2.5 power and has a 10° field of vision.

The telescopic sight is approximately seven inches long and is equipped with an eyepiece of soft rubber. The reticle is marked in the following graduations: vertical from 0 to 15, horizontal 20 mils each side of the center, the markings being at 5 mil intervals. The horizontal line intersects the vertical scale at the 3 mark.

The telescopic sight is removable and when not in use is carried in a well constructed canvas case which has a heavy coating of lacquer on the outside for waterproofing. The case is fitted on the inside with a wooden spacer to secure the sight when it is inside. A small pocket to hold the sight cleaning brush is also constructed inside the case.

The rifle is also provided with a folding monopod which is pivoted on the lower band.

SPECIFICATIONS

Weight (w/ telescopic sight)         10 lbs., 8 oz.
Length (overall w/o bayonet) 50.25 ins.
Sight radius 26.9 ins.
Principle of operation Manual, bolt-action
Feeding device Box magazine
Capacity of feeding device 5 rounds
Cooling system Air
Ammunition types Mod. 38, 6.5 mm ball and reduced charge ball
Rate of fire According to dexterity of user
Type of sight 2.5x telescopic sight
Weight of barrel
Length of barrel 31.4 ins.
Length of rifling 29.1 ins.
Rifling
Twist Uniform R.H. one turn in 7.88 ins.
Form Metford segmental
No. of grooves 4
Depth of grooves
Width of grooves
Chamber pressure
Muzzle velocity 2,400 ft. per sec.
Muzzle energy
Maximum range 2,600 yds.
Effective range (approx.) 600 yds.
Type of mount Folding monopod

Japanese: p. 208.1 (August 1, 1945)

105 mm Field Gun Type 14

Japanese 105 mm Field Gun Type 14

The Japanese 105 mm gun, Type 14, is a medium field weapon mounted on a two-wheeled carriage and drawn by a prime mover. The tube, of built-up construction, is retracted above the trails when in traveling position to provide proper balance. A breechblock of the interrupted screw type is used.

The weapon has split trails which may be adjusted to equalize cant. The wheels are equipped with rubber or steel tires.

The recoil system is the variable, hydropneumatic floating piston type. The fluid passage to the other side of the two air cylinders is suitably interrupted when the elevation is increased.

The traversing mechanism consists of a worm and arc gear. The elevating mechanism is of the arc gear type. A spring equilibrator is attached to the gun, since the trunnion is retracted in relation to the tube. The sighting equipment consists of a panoramic sight and a drum type range scale.

SPECIFICATIONS

Caliber         105 mm (4.13 ins.)
Weight (traveling position)
Weight (firing position)
Length (traveling position)
Length (firing position)
Height (traveling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of bore
No. of grooves
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity 2,040 f/s
Max. range (horizontal) 16,500 yds.
Max. range (vertical)
Rate of fire 6-8 r.p.m.
Traverse 30°
Elevation 43°
Depression
Length of recoil
Ammunition H.E. (long pointed), H.E., Shrapnel, Chemical, A.P.
Wt. of projectile (H.E.) 33 lbs.

German: p. 114.3 (August 1, 1945)

81 mm Mortar Model 3

Japanese 81 mm Mortar Model 3

The Japanese 81 mm Mortar, Model 3, is a forerunner of the Model 97 (1937). It was manufactured at the Yokosuka Navy Arsenal in 1943.

The tube is a smooth-bore type and has two collars machined on the forward part for securing the bipod clamp. The bipod, constructed of light weight tubing, is very unstable. There is no cross leveling device, and rough cross leveling adjustments could be made by breaking the bipod support and moving the leg on the low side inward.

The base plate is relatively heavy, and is believed to be identical with that now used with the 90 mm Mortar, Model 94. It is interchangeable with the base plate for the Model 97.

Both traversing and elevating mechanisms employ the square type threads rather than the usual and more efficient buttress type as used on Model 97. No sight was recovered with the mortar.

SPECIFICATIONS

Weight of tube        47 lbs.
Weight of bipod 25 lbs.
Weight of base plate 95 lbs.

Japanese: p. 122.1

27 mm Doppel Schuss: Double Barrel Signal Pistol

27 mm Doppel Schuss: Double Barrel Signal Pistol

The 27 mm double barrel signal pistol is unique in that the basic parts such as the trigger, trigger-guard, lever release, hammer assembly and switch lever, as well as all pins, are made of steel; the remaining parts, with the exception of the wooden forestock and hand grips, are made of an aluminum alloy.

The firing mechanism is of the continuous pull type incorporating concealed hammers. A switch lever is located on the top rear of the pistol frame to control the firing mechanism. By use of this lever, either one of the two barrels, or both, can be fired by action of the trigger. Turning the lever to the left allows only the left barrel to be fired; turning it to the right allows only the right barrel to be fired. With the lever in the center position, both barrels fire simultaneously. Breaking of the piece is accomplished by pushing forward the release lever which is located just forward of the trigger guard. Indicator pins located in the breech plate show whether the respective barrels are loaded. A safety lever is located on the left side of the receiver. The words “Feuer” and “Sicher” indicate the two positions of Fire and Safe.

Another model, a double barrel air force signal pistol of somewhat similar design, is pictured in the inset above.

SPECIFICATIONS

Weight         3 1/8 lbs.
Length 13 7/8 ins.
Ammunition types
Weight of barrel
Length of barrel 9 1/8 ins.
Rifling (smooth bore)
Muzzle energy
Maximum range

*Signal cartridge with single star–max. vertical range 260 ft.

German: p. 202.1 (May 1, 1945)

Kfz. 2 S: Amphibious Volkswagen

Kfz. 2 S: Amphibious Volkswagen Schwimmwagen

The basic construction of this vehicle is identical with that of the standard type 82 Volkswagen. Front wheel drive has been added to the ingenious positive lock differential rear drive already employed and removes all objections to its poor cross-country performance.

The steering assembly and the front wheel suspension are placed outside a watertight bulkhead.

A rubber sealed stuffing box is used for the front wheel drive shaft. In the rear the suspension is mounted outside the watertight hull. The only openings are for each drive shaft. These are entirely hooded by two bellows type rubber boots that sheath the axle allowing movement in all directions.

Shock absorbers are provided for each wheel. In the front they are mounted outside the hull. In the rear, a watertight shaft extends through the hull from shock absorber to wheel.

Normal grease seals on the rear axle keep water from seeping into the differential and transmission assemblies.

The transmission, transfer case and the positive locking differential comprise a unit assembly secured to the floor at its extreme rear end. A power takeoff has been added to the normal transmission to provide front wheel drive. A cross-country gear position is also provided. It is an extra low gear necessitating the normal transmission be kept in neutral position when used.

The clutch is a dry single disc foot operated type. The propeller assembly is mounted on a spring-loaded hinge that is positioned in the rear directly in line with the hand crank pulley. It incorporates a slip clutch to eliminate damage to the propeller blades by underwater obstructions. Engagement direct with the engine is made through a dog clutch sealed by a rubber bushing on the engine side.

SPECIFICATIONS

Weight         2,040 lbs.
Loading capacity 960 lbs.
Length (overall–propeller down) 150 ins.
     (overall–propeller up) 140 ins.
Width (overall) 55 ins.
Height (overall to top of windshield) 57 ins.
     (overall less windshield) 38 ins.
Ground clearance 11.5 ins.
Tread centers 47 ins.
Wheelbase 78 ins.
Tire size 5.25 x16–one spare
Fuel tank 13 gallons, 70 octane
Fuel consumption (land) 20 m.p.g.
     (water) Unknown
Fording depth Unlimited
Speed (land) 46.5 m.p.h.
     (water) 7.5 m.p.h.
Engine 4 cyl. horizontally opposed, air-cooled
Horsepower 24.5 at 3,300 r.p.m.
Ignition Bosch, 6 volt coil
Battery 6 volt
Transmission 4 speeds forward, 1 reverse
Steering Normal–front wheels

German: p. 58.1

m. Zgkw. 8t Sd. Kfz. 7 (3.7 cm Flak 36): Antiaircraft Gun on Semitrack Chassis

m. Zgkw. 8t Sd. Kfz. 7 (3.7 cm Flak 36): Antiaircraft Gun on Semitrack Chassis

The 3.7 cm Flak 36 has also been mounted on the chassis of the 8-ton medium prime mover described on page 54. Data on the weapon may be found on page 130.1.

German: p. 54.1 (April 1, 1945)

m. Zgkw. 8t Sd. Kfz. 7 (2 cm Flakvierling 38): A.A./A.T. Gun on Semitrack Chassis

m. Zgkw. 8t Sd. Kfz. 7 (2 cm Flakvierling 38): A.A./A.T. Gun on Semitrack Chassis

The 2 cm Flakvierling 38 has been mounted, as illustrated above, on the chassis of the 8-ton medium semitrack prime mover described on page 54. Details of the weapon and its performance may be found on page 133.

German: p. 54.1 (April 1, 1945)

Pz. Jäg. “Panther” für 8.8 cm Pak 43/3 (Sd. Kfz. 173): S.P. Antitank or Assault Gun (Gun Motor Carriage)

Jagdpanther - Pz. Jäg. Panther für 8.8 cm Pak 43/3 (Sd. Kfz. 173)

The standard Model A Panther chassis is used for building this vehicle. The vehicle embodies all of the engineering principles and methods of design accumulated by the Germans up to the time of its production, and is quite effective as an antitank or assault weapon.

The hull and fighting compartment are of all welded construction. The fighting compartment is 45 inches in height at the front and 57 inches at the rear. The length of the roof is 93 inches and the width 72 inches.

The steering mechanism, “one radius steering,” is new. It is unnecessary to engage the transmission in order to turn or traverse the tank through 360 degrees. The use of either steering lever will traverse the tank in a small radius or on the spot. The annulus gear of each of the two epicyclics is driven by the transmission output shaft and is subject to seven speeds forward and one reverse. The sun gears are held stationary on the straightaway by steering brakes. In making a turn, the inside sun gear is released to rotate backward for a sharper turn, the inside sun gear is driven by engagement through a steering clutch with the engine.

The vehicle is armed with the 8.8 cm Pak 43/3 gun in a massive cast steel mantlet which is flexibly mounted in a cast steel ring welded to the front plate. Traverse is 11 degrees. Stowage is provided for 29 rounds of each of two types of ammunition. One M.G. 34 is ball mounted in the front plate to the right. Driver’s vision is by periscope. Fuel capacity is 193 gallons, of which 34 gallons are held in auxiliary.

SPECIFICATIONS

Weight         45 tons
Length (overall) Including gun 28 ft., 4 ins.
     Excluding gun 22 ft., 8 ins.
Width (overall) 10 ft., 10 ins.
Height (overall) 9 ft., 10 ins.
Ground clearance 21 ins.
Tread centers 8 ft., 7½ ins.
Ground contact 12 ft., 9½ ins.
Width of track 26 ins.
Pitch of track 6 ins.
Track links 67
Fording depth 67 ins.
Theoretical radius of action
     Roads 124 miles
     Cross-country 62 miles
Speed
     Roads 34 m.p.h.
     Cross-country 15-18 m.p.h.
Armor
     Front plate 80 mm at 55° to the vertical
     Sides 45 mm at 30° to the vertical
     Rear 40 mm at 30° to the vertical
     Top 17 mm at 85° to the vertical
Armament 8.8 cm Pak 43/3 (MV 3.280 f/s, A.P.C.B.C.), M.G. 34
Ammunition (Rds.) 58 (8.8 cm)
Engine Maybach HL 230 P 30 V12 gasoline
Transmission Synchromesh 7 speeds forward, 1 reverse
Steering One radius double drive epicyclic
Crew 5

German: p. 38.1 (August 1, 1945)

Anti-Vehicular Yardstick Mine

Japanese WWII Anti-Vehicular Yardstick Mine

This Japanese land mine, of Naval origin, is usually found buried in landing strips. Almost any vehicle will activate the mine, but its use as an anti-personnel device is limited since a pressure of approximately 336 pounds is necessary to set it off.

The mine consists of an oval shaped tube of sheet metal with a cap on both ends; an explosive charge comprising eight blocks of picric acid, each cast in a paper container and coated with paraffin; and four percussion type fuzes.

The picric acid blocks which are flattened on one side do not fill the mine completely. The space between the flat side of the blocks and the wall of the case accommodates the protruding heads of the fuzes which are inserted between blocks.

The percussion type fuze consists of a cylindrical body which houses the striker release plunger, a booster housing, and a striker housing. The two latter parts are identical in external appearance and screw into the sides of the main body diametrically opposite each other.

The striker release plunger, a split pin with an enlarged flat head, is positioned in the fuze body by a copper shear wire. A second hole 90 degrees from the shear wire hole accommodates a safety wire. The lower end of the plunger is split by a slot, the width of which is increased on the inner end.

The mine is held in an unarmed position by the safety wire which is inserted through a hole in one of the end caps, and extends the entire length of the mine. A spring clip on the cap holds the wire in place. When the mine is to be put into operation, the safety wire is removed and a burying plug is screwed into the hole in the cap to make the assembly waterproof. A thick tarry substance is applied to-the seams around the end caps probably for the same purpose.

SPECIFICATIONS

Length (overall)        36 ins.
Diameter (oval) 3.35 x 1.8 ins.
Total weight 10.58 lbs.
Weight of mine 4.63 lbs.
Weight of filling 5.95 lbs.
Weight of each explosive block 3/4 lb.
Filling Picric acid
Weight of complete fuze .29 lb.
Color Brown outside; black lacquer inside

Japanese: p. 308.1 (March 1, 1945)

28/32 cm schweres Wurfgerät 40 and 41: Transportable Rocket Projectors

28/32 cm schweres Wurfgerät 40 and 41: Transportable Rocket Projectors These two rocket projectors, or ramps, differ from each other only in construction details and in the material used. The Schweres Wurfgerät 40 is made of wood and weighs 115 pounds; the 41 model is of metal, weighing 243 pounds. Each is designed to carry four crates of the 32 cm incendiary rocket (page 353) or the 28 cm high explosive rocket (page 354).

Either model is adjustable for elevation. Firing is accomplished by the hand electric firing system provided for the crates themselves. Maximum ranges for these projectors are identical: 2,106 yards for the 28 cm Wurfkörper Spr. and 2,406 yards for the 32 cm Wurfkörper M. Fl. 50.

German: p. 349 (May 1, 1945)