Imperial Japanese Army Ammunition - 7.7mm and 7.92mm Projectiles

Army Projectiles: Part 2

Type 99 (Rimless) 7.7mm Ammunition

Continuing the tradition of the 6.5mm round, the 7.7mm cartridge has several different sizes based on what type of projectile is used.

There are 5 listed variants:

Ball round with CuNi jacket and lead core;

Tracer round with CuNi jacket and lead core;

A.P. round with CuNi jacket and Hard Steel core;

Blank round with Paper or Wooden projectile.

Type 99 (Rimless) 7.7mm Ammunition Characteristics

 

                                              Ball                    A.P.                Tracer             Wooden

Overall Length (inches)        3 and 9/54           3 and 9/54       3 and 9/54          3 and 9/54

Length of Case (inches)       2 and 1/4                2 and 1/4           2 and 1/4              2 and 1/4

Length of Projectile (inch)    2 and 17/54             2 and 17/54       2 and 17/54          2 and 17/54

Weight of Projectile              181 grams                                                          5 grams

The rimless 7.7mm round was used in:
Rifles: Type 99 rifle, Type 2 rifle, Type 4 rifle
LMGs: Type 99 LMG, Type 97 LMG
HMGs: Type 92 HMG, Type 1 HMG

To differentiate the ammunition, color bands were used similar to the 6.5mm Arisaka round.

Type | Band
-----------------
Ball - Pink
Tracer - Green
A.P - Black
Blank - Wood
Blank - Paper (purple)

Notes:
The heavy machine guns use feed strips of 30 rounds. When used in light machine guns and the rifle, this ammunition is packed in 5-round clips. In addition to the usual brass cartridge cases, ammunition with a steel case has been found.

Type 92 (Semi-rimmed) 7.7mm Ammunition

While the varied Type 92 rounds have different lengths in some cases, the interesting part is that it did not have a blank variant in wood or paper.

That being said, there were still 5 variants, all using a CuNi jacket:

Ball round with lead core;

Tracer round with lead core;

A.P. round with Hard Steel core;

Incendiary round with W.P. and lead core;

H.E. round with P.E.T.N. and lead core.

Type 92 (Semi-Rimmed) 7.7mm Ammunition Characteristics

                                              Ball                 A.P.               Tracer          Incendiary      H.E.

Overall Length (inch)           3 and 9/54        3 and 9/54       3 and 9/54         3 and 9/54          3 and 9/54

Length of Case (inch)           2 and 1/4            2 and 1/4          2 and 1/4           2 and 1/4             2 and 1/4

Length of Projectile (inch)    2 and 25/54        2 and 25/54       2 and 1/2           2 and 1/2             2 and 1/2

Weight of Projectile             203 grams       162 grams     155 grams     162 grams       162 grams

The semi-rimmed rounds were used in the Type 89, used by the Army Air Force, and the Type 92 HMG used by the Army.

To differentiate the ammunition, color bands were used similar to the 7.7mm Arisaka round.

Type | Band
-----------------
Ball - Pink
Tracer - Green
A.P - Black
Incendiary - Magenta
H.E. - Purple

Notes
The type 92 HMG uses feed strips of 30 rounds. When used for aircraft flexible machine guns, this ammunition is packed in 5-round clips in a manner corresponding to the packing of rimless, rifle ammunition; but the clip is of larger size to accommodate the larger bore of the semi-rimmed type. The P.E.T.N. in the H.E. round is set off by the heat of the impact.

7.92mm Aircraft Machine Gun Ammunition

The manual mentions a few oddities here. It mentions that the 7.92mm round was used in 3 different guns: Bren type LMG, Type 98 flexible ACMG, and Type 100 flexible ACMG. The Bren's would've been captured examples produced by the Chinese chambered in 8x57mm IS (7.92x57mm Mauser) and the Type 100 twin-barrelled design. The Type 98 was a direct copy of the German MG-15.

Only 4 different rounds were used:

Ball round with Gilding metal jacket and lead core;

A.P. round with CuNi jacket and Hard Steel core;

Incendiary round with CuNi jacket and W.P. and lead core;

H.E. round with CuNi jacket and P.E.T.N. and lead core.

 7.92mm Aircraft Machine Gun Ammunition Characteristics

 

 

                                              Ball                     A.P.              Incendiary           H.E.

Overall Length (inch)            3 and 5/32               3 and 5/32        3 and 5/32                3 and 7/54

Length of Case (inch)           2 and 7/32               2 and 7/32        2 and 7/32                2 and 7/32

Length of Projectile (inch)    1 and 7/16               1 and 25/54     1 and 25/54

Weight of Projectile              180 grams          182 grams      182 grams

 



Another oddity is the Ball type round did not have a color marking.


Type | Band
-----------------
A.P - Black
Incendiary - Magenta
H.E. - White

Notes:
The Bren type LMG uses a box-type magazine similar to the US BAR LMG. The Type 98 and type 100 ACMGs use saddle-type magazines.

Next Time: 8mm and 9mm Ammunition

Imperial Japanese Army Ammunition - 6.5mm Projectiles

Army Projectiles - Part 1

Type 38 6.5mm Ammunition

There are three different 6.5mm rounds detailed in the Technical Manual, describing the size and weight of the cartridge;  Ball, Training, and Wooden.

They all used the same case and vary in the length of the projectile, overall length and weight of the projectile.  It is interesting to note that there were 2 training, or blank, rounds and 1 practice (Ball) round. 

Ball rounds had a CuNi or steel jacket and a lead core;

Tracer rounds had a CuNi jacket and lead core;

Blank rounds had either a paper or wood projectile;

Practice ball rounds were snub-nosed, had a copper jacket and a lead core.

6.5mm Ammunition Characteristics

                                               Ball                         Training                   Wooden 

Overall Length                       3 inches                  2 and 1/2 inches         2 and 31/32 inches

Length of case                       2 inches                  2 inches                     2 inches

Length of projectile               1 and 1/4 inches       1/4 inches                  1 and 19/54 inches

Weight of projectile               138 grams               34 grams                   5 grams



To tell these rounds apart, they had a colored band located where the projectile and the case meet.  The type of shot and color are as follows:

Ball : Pink

Tracer : Green

Blank : Wood

Blank : Paper (purple)

Practice Ball : Pink

The 6.5mm cartridge was, as mentioned in the introduction, still fairly common in the Japanese inventory.

 

6.5mm Rifles: Type I rifle, Type 1 rifle, Type 30 rifle, Type 35 rifle, Type 38 rifle, Type 44 Carbine, Type 97 rifle

6.5mm LMGs: Type 11 LMG, Type 96 LMG

6.5mm HMGs: Type 3 HMG

Notes:

Ammunition when used in rifles and LMGs will be found in clips of 5 rounds each.  When used in HMGs it will be found in feeder strips of 30 rounds each.  The wooden bullet round is used with the rifle to launch the rifle smoke grenade.  The paper bullet round is used to launch rifle grenades.  The propelling powder used in the blank rounds is nitro-cellulose while in the other rounds it is graphite-coated nitro-cellulose.

Next Time: 7.7mm and 7.92mm Ammunition

Imperial Japanese Army Ammunition - Army Color Systems

The Japanese Army had two color systems for marking ammunition.  The Old and New systems differed in the number of color bands they used, the New system had the body of the projectile colored to indicate the group in which the type of ammunition was categorized and the color bands determined specific properties.

Old Color System

Notes:

Common Explosive Types

Japanese characters giving the type number of the projectile (painted on projectile) and type number of the gun (painted on the case) appear only when there is a chance of confusion with similar projectiles or cases.

Chemical (Gas or Liquid Filled) Projectiles

Notes:

Special-Purpose Projectiles

Projectiles designed for special purposes are painted black over all and are identified by a special symbol stenciled near the middle of the body.  A list is provided in the New Color System .

Weight Variation Marking

The variation of individual projectiles from standard weight is important in the ballistics problem and can be corrected for insetting sights.  The variation is therefore indicated by plus/minus signs painted on the projectiles

OVERWEIGHT     

• 1.5 to 2.5 percent overweight      ++
• 0.5 to 1.5 percent overweight      +

STANDARD WEIGHT

• 0.5 percent plus or minus            ±

UNDERWEIGHT     

• 0.5 to 1.5 percent underweight     -
• 1.5 to 2.5 percent underweight     - -
  
  
  

New Color System

Future examples will show both types of twin color bands

Notes:

Common Explosive Types

Hollow charge ammunition is distinguished from other types in the H.E. high grade steel (yellow band) group by the presence of the symbol.

Chemical (Gas or Liquid Filled) Projectiles

Notes:

Special-Purpose Projectiles

Projectiles designed for special as listed below are identified by the overall body color and by a special symbol stenciled near the middle of the body.

Projectile       Color of Body

                                                      Smoke*        White             

                                                      Incendiary^    Yellow           

                                                      Illuminating    Red                

                                                      Target            Black              

                                                      Sand-filled      Black           

   

*: Signal or Screening
^: Non-liquid

Next Time: Rifle Caliber Ammo

Imperial Japanese Army Ammunition - Introduction

Army Ammunition - Introduction

The following is taken directly from a U.S. Technical Manual on Japanese Explosive Ordnance

Japanese Army weapons are generally copies of German or French designs or are developed following their customs. In comparison with weapons used by other countries in the past few years, the Japanese weapons appear to be outmoded and ineffective.

This is particularly true in considering small arms for if the Japanese ever made any serious attempt to standardize small arms and small arm ammunition there is little evidence of it in the many different calibers and types in use by them. The standard weapon prior to 1930 was 6.5mm, but shortly thereafter this was superseded by 7.7mm weapons. However, this change was never completed and 6.5mm weapons were used extensively in the last war. The foreign influence is apparent particularly after 1939 when aircraft machine guns of German and Italian design were copied.

The earlier aircraft machine guns and aircraft cannon were either modifications of Japanese ground mounts or copies of foreign guns. In more recent years, however, the Japanese designed aircraft cannon as large as 120mm, but nothing larger than 57mm was ever put into service.

Most Japanese artillery weapons were characterized by their immobility as very few of them were designed for rapid motor transport. Although 105mm and 150mm weapons were frequently encountered, the standard field piece was 75mm.

One outstanding characteristic of Japanese Army ammunition is the large variety of types and sizes of mortars which were in use. Mortars were used not only as infantry support weapons but as artillery pieces. They ranged in size from the 50mm Grenade Discharger to the 320mm Spigot Mortar.

The standard Antiaircraft Gun was a 75mm gun but there was also an 88mm Antiaircraft Gun which was one of their most effective artillery pieces and a 105mm AA gun. The Japanese had designed a 150mm Antiaircraft Gun for the defense of the home islands but this was used only in the last few months of the war.

The newest trend in research and development in ammunition was along the line of rockets. Very few types of Japanese rockets were used during the war but there were many experimental models of antitank and artillery rockets in development, ranging in size from 75mm to 60cm.

Research was also being conducted on smoothbore and recoilles waepons but this was a relatively new program and none of these weapons was ever developed beyond the experimental stage.


Next Time: Imperial Japanese Small Arms Munitions



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