Soviet Explosive Ordance - 120mm Mortar Rounds

120mm Mortar Rounds

This will be the last update covering Soviet Mortar rounds, with us taking a look at the 120mm Regimental mortar shells, and their packaging.

120mm Mortar Shell, HE, F-843

The high-explosive shell, F-843, which is fired from 120mm regimental mortars M1938 and M1943 consists of five components:

(1) A point detonating fuze,

(2) a steel shell body filled with HE,

(3) a fin assembly,

(4) an ignition cartridge, and

(5) propellent increments which may be adjusted for zone firing.

The F-843 differs from other 120mm mortar rounds in that the shell body is constructed in two sections.  Each section is threaded, and the two are joined approximately two inches below the gas check bands.  The shell body is thin-walled, contains a maximum of high-explosive, and is designed primarily for blast effect.  The GVMZ fuze, set for delay action, is usually used with this round.

This round is effective against field fortifications and other structures of wood and masonry.

Characteristics

Caliber: 120mm (4.72 in)

Weight of complete round: 16.43kg (36.23 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: TNT

Weight of filler: 3.9kg (8.6 lbs)

Maximum number of increments: 6

Packaging

The illustrated packing box contains two 120mm mortar complete rounds and weighs approximately 48kg (106 lbs).  The box is of sturdy construction, usually a soft wood, with reinforced corners, a hasped and hinged lid, and carrying handles on each end.  The shells are held in place by contour blocking.

The shell bodies are frequently covered with a heavy grease preservative which must be removed before the round is fired.

120mm Mortar Shell, Frag-HE, OF-843

This is the fragmentation high-explosive shell, OF-843, fired from the 120mm regimental mortars M1938 and M1943.  It is designed for fragmentation-blast effect and is used against field fortifications, materiel, and buildings of wood and masonry, as well as against personnel.  The shell body is of thick-walled steel construction.  The OF-843 is similar in size and appearance to the OF-843A but has a greater explosive content.

The GVM, GVMZ, GVMZ-1, M-1, and M-4 fuzes are used with the OF-843.  The GVMZ and GVMZ-1 fuzes have two settings: (1) Instantaneous action, and (2) delay action.  The GVM, M-1, and M-4 are instantaneous-action fuzes.

Characteristics

Caliber: 120mm (4.72 in)

Weight of complete round: 16kg (35.28 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: TNT

Weight of filler: 2.68kg (5.9 lbs)

Maximum number of increments: 6

Packaging

The illustrated packing box contains two 120mm mortar complete rounds and weighs approximately 44kg (97 lbs). The box is of sturdy construction, usually a soft wood, with reinforced corners, a hasped and hinged lid, and carrying handles on each end. The shells are held in place by contour blocking.

The shell bodies are frequently covered with a heavy grease preservative which must be removed before the round is fired.

120mm Mortar Shell, Frag-HE, OF-843A

This is the fragmentation high-explosive shell, OF-843A, fired from the 120mm regimental mortars M1938 and M1943.  It is primarily for anti-personnel use.

The cast iron body is thick-walled, designed for maximum fragmentation, and has a correspondingly smaller explosive content.  This round may be identified by the "A" ending the code number and by a black band located just forward of the fin assembly.

Fuzes GVM, GVMZ, GVMZ-1, and M-4 are used in this shell.

Characteristics

Caliber: 120mm (4.72 in)

Weight of complete round: 15.88kg (35 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: Amatol 80/20

Weight of filler: 1.58kg (3.48 lbs)

Maximum number of increments: 6

Packaging

The illustrated packing box contains 2 unfuzed fragmentation high-explosive shells, OF-843A, with ignition cartridges and propellent increments, and weighs approximately 44kg (97 lbs). The box is of sturdy construction, usually a soft wood, with reinforced corners, a hasped and hinged lid, and carrying handles on each end. The shells are held in place by contour blocking.

The shell bodies are frequently covered with a heavy grease preservative which must be removed before the round is fired.  The fuze wells of the rounds are closed with plastic plugs.  Fuzes are packed in seperate boxes.

120mm Mortar Shell, Incendiary, Z-843A

This is the incendiary shell, Z-843A, fire from the 120mm regimental mortars M1938 and M1943.  It is similar to the OF-843A and D-843A shells in appearance, but can be distinguished from them by the "З" (Z) beginning the code number, the "TP" (TR) designating the shell filler, and the red band around the shell body.  This red band is approximately one-half inch wide and is located just below the gas check bands.

The cast iron shell body of this round is filled with an incendiary composition and a burster charge designed to rupture the shell and release the incendiary composition.  The M-1 and M-4 fuzes are used with this round.

Characteristics

Caliber: 120mm (4.72 in)

Weight of complete round: 17.19kg (37.9 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: Incendiary composition and explosive

Weight of filler:
-Bursting Charge: 0.059kg (0.13 lb)
-Incendiary Composition: 1.3kg (2.86 lbs)

Maximum number of increments: 6

Packaging

The illustrated packing box contains 2 complete rounds and weighs approximately 44kg (97 lbs). The box is of sturdy construction, usually a soft wood, with reinforced corners, a hasped and hinged lid, and carrying handles on each end. The shells are held in place by contour blocking.

The shell bodies are frequently covered with a heavy grease preservative which must be removed before the round is fired.

120mm Mortar Shell, Smoke, D-843A

The smoke shell, D-843A, is fired from the 120mm regimental mortars M1938 and M1943.  It is similar in size and appearance to the fragmentation high-explosive mortar shell, OF-843A.  The smoke round, however, can be distinguished from the fragmentation high-explosive round by the "Д" (D) in the code number and by a half-inch-wide black band located just below the gas check bands.

The cast iron shell body of the D-843A mortar is filled with a smoke composition (usually yellow phosphorus) and with a burster charge which serves to rupture the shell body and scatter the smoke composition.  The phosphorus ignites and burns spontaneously upon contact with air, and the resulting fire is difficult to extinguish.

The GVM, GVMZ, GVMZ-1, and M-4 fuzes are used in this shell.

Characteristics

Caliber: 120mm (4.72 in)

Weight of complete round: 16.51kg (36.4 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: Phosphorus and explosive

Weight of filler:
-Bursting Charge: 0.073kg (0.16 lb)
-Incendiary Composition: 1.97kg (4.34 lbs)

Maximum number of increments: 6

Packaging

The illustrated packing box contains 2 complete rounds and weighs approximately 44kg (97 lbs). The box is of sturdy construction, usually a soft wood, with reinforced corners, a hasped and hinged lid, and carrying handles on each end. The shells are held in place by contour blocking.

The shell bodies are frequently covered with a heavy grease preservative which must be removed before the round is fired.

Next time: 37mm and 45mm Artillery Projectiles

Imperial Japanese Army Ammunition: 88mm to 120mm Projectiles

Japanese Explosive Ordnance: Army and Navy Ammunition

Type 100 8cm (88mm) High Explosive A.A. Long-Pointed Projectile

Weight of complete round: Not Available
Weight of complete projectile (with fuze): Approx. 19.6 lbs
Weight of empty projectile (with Aux Fuze): 7.4kg
Weight of filling: 0.9kg
Filling: TNT
Diameter at bourrelet: 88mm
Length of projectile (w/o fuze): 298mm
Length of propellant case: 570mm
Length of assembled round (w/o fuze): 804mm
Diameter of base of case: 100mm
Width of rotating band: Forward - 8mm Aft - 8mm
Distance between rotating bands: 6mm

Fuzing: Type 100 mechanical time fuze (combination time and impact) with an auxiliary detonating fuze. The auxiliary fuze is the same as that used in the 7cm (75mm) H.E.A.A. projectile Type 90.

Used in: Type 99 8cm A.A. gun. This is a gun modeled after one of the Germans 88mm guns.

Case:
-Length: 567mm
-Diameter at base: 137mm
-Construction: The case is made of drawn brass and is machined for about 2 and 3/4 inches above the rim - It is a rimmed case with a slight taper and a bottleneck.
Propellant: No.16 cylindrical, 2,330g



9cm (90mm) High Explosive Projectile

Weight of projectile, filled: 7.79kg
Weight of filling: 0.59kg
Filling: Crude TNT
Diameter at bourrelet: 90mm
Length overall (w/o fuze): 265.1mm
Length of projectile body (w/o nose piece): 209.6mm
Length protruding from case (w/o fuze): 246.1mm
Width of rotating band: No Data

Fuzing:
-Type 88 instantaneous nose fuze (Howitzer - mortar type)
-Type 88 short delay nose fuze (Howitzer - mortar type)

Used in:
This is an antiquated weapon classified as a mortar by the Japanese by virtue of length of tube, muzzle velocity, etc., but bearing only a remote resemblance to other Japanese mortars. It is breech-loading, using an interrupted thread breechblock, and employs projectiles embodying the conventional features of design of common breech-loading artillery pieces.

Remarks: The body of this projectile is painted black overall. There is a shallow groove immediately below the bourrelet hich may be painted yellow or green.



9cm (90mm) High Explosive Semisteel Projectile

Weight of projectile, filled: 7.86kg
Weight of filling: 0.65kg
Filling: TNT
Diameter at bourrelet: 90mm
Length overall (w/o fuze): 263.5mm
Length protruding from case (w/o fuze): 246.1mm
Width of rotating band: 15.9mm

Fuzing:
-Type 88 instantaneous nose fuze (Howitzer - mortar type)
-Type 88 short delay nose fuze (Howitzer - mortar type)

Used in:
This is an antiquated weapon classified as a mortar by the Japanese by virtue of length of tube, muzzle velocity, etc., but bearing only a remote resemblance to other Japanese mortars. It is breech-loading, using an interrupted thread breechblock, and employs projectiles embodying the conventional features of design of common breech-loading artillery pieces.

Remarks: The projectile is painted black overall with a 1/2 inch green or yellow band before the rotating band. The fuze adapter is painted red.



10cm (105mm) Ammunition

There are three 105mm howitzers and four 105mm guns in use by the Japanese Army. These guns are designated 10cm by the Japanese but have an actual bore diameter of 105mm. The projectiles are in most cases interchangeable for use in all these weapons and are assembled with different size cases for use in the different weapons. Only one weapon, the Type 14 year A.A. gun uses fixed ammunition, all the other weapons using semifixed ammunition. In this section the cases and projectiles will be treated seperately as was done with 75mm ammunition.

Type 91 10cm (105mm) High Explosive Projectile

Weight of projectile, filled (w/o fuze): 15.9kg
Weight of filling: 2.3kg
Filling: Cast TNT
Diameter at bourrelet: 104mm
Length overall (w/o fuze): 427mm
Length protruding from case (w/o fuze): 389.7mm
Width of rotating band: 22.2mm

Fuzing:
-Type 88 instantaneous nose fuze (Howitzer - mortar type)
-Type 88 short delay nose fuze (Howitzer - mortar type)

Used in:
-Type 91 howitzer, case 9 and 1/2 inches
-Type 88 field gun, case 11 and 1/8 inches
-Type 92 field gun, case 29 inches
-Type 14 year field gun, case 18 and 1/8 inches



Type 91 10cm (105mm) High Explosive Long Pointed Projectile

Weight of projectile, filled (w/o fuze): 15.7kg
Weight of filling (white composition): 2.3kg
Filling:
1.Cast TNT
2. White composition of ammonium nitrate, cyclonite, and guanidine nitrate
Diameter at copper bourrelet: 104.2mm
Length overall (w/o fuze): 501.7mm
Length protruding from case (w/o fuze): 423.9mm
Width of rotating band: 22.2mm
Width of copper bourrelet: 20.6mm

Fuzing:
-Type 88 instantaneous nose fuze (Howitzer - mortar type)
-Type 88 short delay nose fuze (Howitzer - mortar type)

Used in:
-Type 91 howitzer, case 9 and 1/2 inches
-Type 88 field gun, case 11 and 1/8 inches
-Type 92 field gun, case 29 inches
-Type 14 year field gun, case 18 and 1/8 inches
-Type 14 year A.A. gun (fixed ammunition), case 22 and 1/4 inches

Remarks: This projectile has been recovered with either a copper or a machined bourrelet



12cm (120mm) Shrapnel Projectile

Weight of projectile, filled (w/o fuze): 19.88kg
Ejecting Charge: Black Powder contained in the base of the projectile and in a central brass tube.
Shrapnel Filling: 539 lead balls (12.5g each) packed in a resin matrix. The balls are separated from the ejection charge by a steel disc which rests on a shoulder in the projectile cavity.
Diameter at bourrelet: 119mm
Length overall (w/o fuze): 314.3mm
Length protruding from case (w/o fuze): 293.1mm
Width of rotating band: 9.5mm

Fuzing:
-Type 88 35-second combination fuze

Used in:
-Type 38 Howitzer

Case:
-Length: 83mm
-Diameter of base: 128mm
-Weight (empty): 3 pounds, 4 and 5/8 ounces
-Construction: The brass case is straight sided and of the rimmed type

Propellant: The propellant is in two increments, each encased in a silk bag with a small ignition charge sewed to the bottom of each bag. The first increment is nitrocellulose in 5/16 inch square flakes and the second increment is nitrocellulose in 1/18 inch square flakes.
Weight of propellant:
-1st increment: 11 oz
-2nd increment: 6 and 3/8 oz



12cm (120mm) Armor Piercing High Explosive Projectile

Weight of projectile, filled and fuzed: 20kg
Weight of filling: 1.3kg
Filling: Picric Acid
Diameter at bourelet: 119mm
Length overall: 379.4mm
Length protruding from case: 339.7mm
Width of rotating band: 11.1mm

Fuzing:
-Type 88 small base fuze (Howitzer - Mortar type)

Case:
-Length: 83mm
-Diameter of base: 128mm
-Weight (empty): 3 pounds, 4 and 5/8 ounces
-Construction: The brass case is straight sided and of the rimmed type

Propellant: The propellant is in two increments, each encased in a silk bag with a small ignition charge sewed to the bottom of each bag. The first increment is nitrocellulose in 5/16 inch square flakes and the second increment is nitrocellulose in 1/18 inch square flakes.
Weight of propellant:
-1st increment: 11 oz
-2nd increment: 6 and 3/8 oz

Used in:
-Type 38 Howitzer




Next Time: 15cm Ammunition

Imperial Japanese Army Ammunition - 7cm (75mm) Projectiles

Introduction to Army 7cm (75mm) Ammunition 

 

There were ten or more 75mm guns in use in the Japanese Army. Though the weapons vary considerably in design, length of bore, and employment, the bore diameter (75mm) is held constant and in large part the projectiles are designed to be interchangeable for numerous guns. In this way, identical projectiles may be assembled with different sizes of case and propellant charges to fit the various weapons.

For this reason the cases and propellant charges for the different weapons will be treated separately and the projectiles will be presented as a group of designs which are potentially interchangeable for all Army 75mm guns. The specific purpose of a given projectile or a given gun will limit the occurrence of many of the possible combinations.

Ammunition for Japanese Navy guns designated "8cm" is comparable in size to Army 7cm, but the Navy guns have a bore diameter of 3 inches (76.2mm) and Army and Navy projectiles and ammunition are not interchangeable. Navy guns as well as Army guns are found commonly in shore defenses, but the identity of the installations, weapons, and ammunition remains distinctly Army or Navy.

*: For convenience in reference, this group, in which the propellant cse bears the multiple designation for four weapons, will be termed "Type 38 Field Gun Group"

KEY: Blank signifies that the indicated combination of projectile and propellant case has neither been recovered nor found listed in Japanese documents. "No Data" indicates that this combination is listed in documents or has been recovered, but that no information on the propellant is available.


7cm (75mm) H.E.A.A. Projectile

_{Note - The drawing given here is based on a Japanese drawing labelled only "Circular-layered projectile". The projectile is of apparent 75mm size and the body appears to be made up of numerous steel rings bolted together with several bolts which are grooved at intervals to produce better fragmentation.}

This projectile is believed to be the same referred to in other documents as "H.E.A.A. Projectile" for the Type 11th year field A.A. gun. The following applies only if this presumption is correct.

Weight of projectile, filled and fuzed: 6.60kg
Filling: "ONA", a mixture of picric acid and dinitronaphtalene
Fuzing: Type 10th year A.A. powder time fuze

Used in: Type 11th year field A.A. gun


Type 90 7cm (75mm) H.E.A.A. Long Pointed Projectile

Weight of projectile, filled (TNT): 6.53kg
Weight of filled: 0.385kg
Filling:
-Standard: TNT cast directly into lacquered cavity (Recovered)
-Alternate: Picric acid (Documentary evidence)
Diameter at bourrelet: 75mm
Length overall (w/o fuze): 257mm
Length of projectile from case: 202mm
Width of forward rotating band: 9.5mm
Width of after rotating band: 9.5mm
Width of space between rotating bands: 6.5mm
Width of copper bourrelet: 14mm
Distance from base to after edge of bourrelet: 140mm

Fuzing: Type 89 long pointed powder time fuze in nose. An auxiliary fuze armed by setback and centrifugal force is used immediately below the time fuze



Type 90 7cm (75mm) H.E. Long Pointed Projectile

Weight of projectile, filled (w/o fuze) (TNT): 6.17kg
Weight of filling: 0.49kg
Filling:
-Standard: TNT cast directly into a lacquered cavity (documentary)
-Alternate: "HEINEI" trinitrophenetole (recovered)
Indicated by painted on body

Diameter at bourrelet: 75mm
Length overal (w/o fuze): 317.5mm
Length protruding from case: 267mm
Width of rotating bands:
-Upper: 10.6mm
-Lower: 9.6mm

Fuzing: Type 88 instantaneous (Gun), Type 88 delay (Gun)

Operation and employment:
It is believed this projectile was designed primarily to adapt the Type 88, 75mm high velocity A.A. gun to a dual-purpose field gun (IE: for air and ground targets). The ballistic form of this projectile approximates that of the Type 90 long pointed A.A. projectile, when the A.A. time fuze is installed. The projectile is also used for other weapons as listed below.

Used in:
-Type 88 field A.A. (Special), case 19 and 3/16 inches
-Type 38 field gun group (four weapons), case 11 and 9/16 inches
-Type 90 field gun, case 16 and 11/16 inches
-Type 94 mountain gun

Remarks:
When this projectile is cased for use in the Type 88 field A.A. gun (special), a reduced propelling charge is used. This reduced charge is indicated by a Roman numeral II stenciled on the case.



Type 94 7cm (75mm) High Explosive Projectile

Weight of projectile, filled (TNT): 6.02kg
Weight of filling: 0.81kg
Filling:
-Standard: TNT cast directly into lacquered cavity
-Alternate (1): "ANGA" ammonium nitrate, RDX
-Alternate (2): "HEINEI" trinitrophenetole

Diameter at bourrelet: 75mm
Length overall (w/o fuze): 303mm
Length protruding from case: 264mm
Width of rotating band: 10mm

Fuzing: Type 88 instantaneous fuze (Gun), Type 88 short delay nose fuze (Gun)

Used in:
-Type 41 mountain gun (regimental gun), case 7 and 1/4 inches
-Type 94 mountain gun, case 11 and 3/16 inches
-Type 38 field gun group, case 11 and 9/16 inches
-Type 88 field A.A. gun, case 19 and 9/16 inches
-Type 88 field A.A. (special) gun, case 19 and 9/16 inches
-Type 90 field gun, case 16 and 11/16 inches

Remarks:
Two other designs essentially the same as Type 94 are known:
 1. H.E. Type 10 year.
 2. H.E. Type 90.
These have the same overall length as the Type 94, and have the same external form and general construction except for the following features.

1. The explosive cavity does not taper in the base as in the Type 94, but is straight-sided.
2. The slight boat tail present on the Type 94 is absent in the other designs.
3. Below the rotating band in the Type 10 year designs only, there is an annular groove into which the case is crimped.


Next Time: More 75mm Projectiles

Soviet Explosive Ordnance - 107mm and 160mm Mortar Rounds

107mm Mortar Rounds

The 107mm mortar rounds described in the manual are all for the mountain-pack regimental mortar of the same caliber, and should not be confused with the 120mm regimental mortars in the next update.

107mm Mortar Shell, Frag-HE, OF-841

This steel fragmentation high-explosive shell (light), OF-841, is fired from the 107mm mountain-pack regimental mortar M1938.  The complete round consists of five components: 

(1) A point detonating fuze,

(2) an explosive-filled thin-walled steel shell body,

(3) a fin assembly,

(4) an ignition cartridge, and

(5) propellent increments which may be adjusted for zone firing.

The OF-841 is supplied with propellent increments and ignition cartridges which are for use in the 107mm mountain-pack regimental mortar M1938 only; however, the OF-841A, OF-841T and D-841 are supplied with propellent increments and ignition cartridges designed for use with 120mm mortar rounds in the 120mm regimental mortar, as well as with the propellent increments and ignition cartridges for the 107mm mountain-pack regimental mortar.  Firing tables indicate that the OF-841 can be fired only with 107mm Charges 1 and 3.

The GVMZ and GVMZ-1 fuzes are used in this shell.

Characteristics

Caliber: 107mm (4.21 in)

Weight of complete round: 7.90kg (17.42 lbs)

Weight of propellant: 0.1kg (0.223 lb)

Type of filler: Schneiderite/TNT

Weight of filler: 2.1kg (4.63 lbs)

Maximum number of increments: 3

Packaging

The illustrated packing box has a capacity of four fuzed 107mm fragmentation high-explosive mortar shells, OF-841.  The box is of sturdy construction, usually of a soft wood, with corners dovetailed or reinforced by metal straps or angles.  The shells are held in place by contour blocking.

These rounds, as packed, need only be equipped with the propellent increments to be ready for firing.  The propellent increments are packed separately (in airtight metal cans or waxed cardboard cartons) within the wooden packing box that holds the rounds and must be affixed to the rounds prior to firing.

107mm Mortar Shell, Frag-HE, OF-841A

This cast iron (ЧУГУННАЯ) fragmentation high-explosive shell, OF-841A, is fired from the 107mm mountain-pack regimental mortar M1938.  It can be distinguished from the steel (СТАЛЬНАЯ) fragmentation high-explosive mortar shell, OF-841T, by the "A" at the end of the code number, and by a half-inch-wide black band just forward of the fin assembly.  The location of the black band also distinguishes this shell from the smoke shell, D-841.

In other respects, this round is similar to the OF-841T and the D-841.  Dimensions are approximately the same, and the same propellent increments, ignition cartridges, and fuzes (GVMZ and GVMZ-1) are used.

Characteristics

Caliber: 107mm (4.21 in)

Weight of complete round: 8.76kg (19.31 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: TNT

Weight of filler: 1.15kg (2.54 lbs)

Maximum number of increments: 4

Packaging

The illustrated packing box holds four unfuzed 107mm mortar shells, OF-841A, and separately packed ignition cartridges and propellent increments.  This box is similar in construction to the box in which the OF-841T mortar shells are packed, and the rounds are packed in a similar manner.

Fuze wells in the OF-841A  are closed with plastic plugs; the fuzes are packed in separate boxes.

107mm Mortar Shell, Frag-HE, OF-841T

This steel fragmentation high-explosive shell (heavy), OF-841T, is fired from the 107mm mountain-pack regimental mortar M1938.  It is similar in appearance to the OF-841, but is longer and heavier.

The OF-841T, like the OF-841, has a powerful high-explosive filler.  Its blast is effective against field fortifications, buildings, materiel, and other objects, as well as personnel.

The OF-841T used the propellent increments and ignition cartridges designed for use with 120mm mortar shells in the 120mm regimental mortar, as well as the propellent increments and ignition cartridges for the 107mm mountain-pack regimental mortars.  A maximum of four 120mm increments (Charge 4) can be fired.

The GVMZ and GVMZ-1 fuzes are used with this round.

Characteristics

Caliber: 107mm (4.21 in)

Weight of complete round: 9kg (19.84 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: TNT

Weight of filler: 1.98kg (4.37 lbs)

Maximum number of increments: 4

Packaging

The illustrated packing box has a capacity of four fuzed 107mm fragmentation high-explosive mortar shells, OF-841T.  The box is of sturdy construction, usually of a soft wood, with corners dovetailed or reinforced by metal straps or angles.  The shells are held in place by contour blocking.

The packed rounds are ready for firing except for propellent increments.  The propellent increments, which are packed in airtight metal cans or waxed cardboard cartons, are inclosed in the same wooden packing box with the shells.  They must be affixed to the round prior to firing.

107mm Mortar Shell, Smoke, D-841

This smoke mortar shell, D-841, is fired from the 107mm mountain-pack regimental mortar M1938.  It is similar in appearance to the OF-841T and OF-841A shells, but it can be distinguished from them by the "Д" (D) beginning the code number and by a 0.6 inch, wide black band located 0.6 inches below the gas check bands.

The steel shell body is filled with a smoke composition (usually yellow phosphorus) and with a burster charge which is designed to explode the shell body and scatter the smoke composition.  The phosphorus ignites and burns spontaneously upon contact with the air, and this fire is difficult to extinguish.  This round uses the same propellants, ignition cartridges, and fuzes (GVMZ and GVMZ-1) as the OF-841T.

The smoke mortar shell, D-841, is used primarily as a screening agent, but it is of further tactical importance against personnel and material because of its fragmentation and incendiary effect.

 

Characteristics

Caliber: 107mm (4.21 in)

Weight of complete round: 9.4kg (20.72 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: Phosphorus and explosive

Weight of filler: 

-Bursting Charge: 0.207kg (0.46 lb)

-Smoke Composition: 1.82kg (4.01 lbs)

Maximum number of increments: 4

Packaging

The illustrated packing box has a capacity of four fuzed 107mm fragmentation high-explosive mortar shells, D-841, plus a sufficient number of ignition cartridges and propellent increments for all zones of fire.  The box is of sturdy construction, usually of a soft wood, with corners dovetailed or reinforced by metal straps or angles.  The shells are held in place by contour blocking.

Ignition cartridges and propellent increments are packed in airtight metal cans or cardboard cartons and inclosed in the wooden box, to be affixed to the shell prior to firing.  Fuze wells in the mortar shells are sealed with plastic plugs.  The fuzes are packed in separate boxes.

160mm Mortar Shell, HE, F-852

The shell illustrated is the high-explosive shell, F-852, which is fired from the 160mm divisional mortar M1943.  It is similar in appearance and construction to other Soviet large-caliber mortar shells, but it is approximately twice as heavy as the shells of the next largest caliber.  It is used primarily for demolition purposes.

This round consists of the usual five components: (1) A point detonating fuze, (2) a steel shell body filled with HE, (3) a fin assembly, (4) an ignition cartridge, and (5) propellent increments which can be adjusted for zone firing.

The fuze model for this round is not known, although there is some documentary evidence indicating the use of the M-1 fuze.

It is assumed that markings on this round would conform to the standard marking system for other Soviet mortar rounds and would include such data as the type of filler, filling factory, lot number and year filled, ccaliber, code number, and weight classification.

Characteristics

Caliber: 160mm (6.3 in)

Weight of complete round: 40.08kg (88.18 lbs)

Weight of propellant: ?kg (? lb)

Type of filler: ? (High-Explosive)

Weight of filler: ?kg (? lbs)

Maximum number of increments: ?

Packaging

No illustration available

There is no available packaging data on the 160mm mortar ammunition.  It is assumed that boxes for this ammunition are constructed in the same manner as other large-caliber mortar ammunition boxes; but, because the weight of the shell, the packing box probably contains only one round, one fuze, and one set of propellent charges.

Next time: 120mm Mortar shells 

Imperial Japanese Army Ammunition - 7cm (70mm) Projectiles

 Japanese Explosive Ordnance: Army and Navy Ammunition

We get to the larger caliber projectiles, which include some of the largest used on Japanese tanks, and we start dipping into the howitzer calibers/rounds. Hollow Charge and smoke projectiles also start to make an appearance.



Type 92 7cm (70mm) High Explosive Projectile

Weight of complete round: 4.48kg
Weight of projectile (fuzed): 3.81kg
Weight of filling: 0.59kg
Length of projectile (w/o fuze): 234mm
Length of propellant case: 101mm
Length of assembled round (w/o fuze): 306mm
Diameter of base of case: 81mm
Diameter at bourrelet: 70mm
Width of rotating band: 10mm
Filling:
-Standard: Cast TNT
-Alternate: Pressed mixture of RDX and ammonium nitrate

Fuzing: Type 88 instantaneous nose fuze (Howitzer, mortar type), Type 88 short-delay nose fuze (Howitzer, mortar type)

Propellant:
50g of smokeless powder in 0.5mm square flakes. This powder is contained in four pads made by sewing portions of the powder between two dark blue silk discs. The discs are not of uniform size, holding 5.4, 8.9, 16.8, and 18.7 grams of powder each. A fifth disc, light blue in color, contains a 3.1g black powder ignition charge.

The propellant cases are of two designs. The newer type, designated "B" (OTSU) by the Japanese, is one piece and slips off of the projectile to change the propellant charge. An older design, presumably "A" has a threaded base which may be unscrewed to vary the charge

Used in: Type 92 infantry gun (Howitzer)

Remarks: This projectile is the same as the high explosive Type 92 used in the Type 94 tank gun



Type 92 7cm (70mm) Substitute Projectile

Weight of complete round: No Data
Weight of projectile (fuzed): No Data
Weight of filling: No Data
Filling: Black Powder
Diameter at bourrelet: 70mm
Length of projectile (w/o fuze): 187mm
Length of propellant case: 101mm
Length of assembled round (w/o fuze): 259mm
Diameter of base of case: 81mm
Width of rotating band: 10mm

Fuzing: Type 88 instantaneous nose fuze (Howitzer, mortar type), Type 88 short-delay nose fuze (Howitzer, mortar type)

Propellant: Same as previous projectile

Used in: Type 92 Infantry Gun (Howitzer)



Type 3 7cm (70mm) Hollow Charge Projectile

Weight of complete round: No Data
Weight of projectile (w/o fuze): 2.80kg
Weight of filling: 0.99kg
Filling: A cast mixture of TNT and Cyclonite (RDX) wrapped in varnished paper
Diameter at bourrelet: 69.5mm
Length overall (w/o fuze): 229mm
Length protruding from case: 186mm
Length of projectile body without nose cap: 170mm
Width of rotating band: 10mm

Fuzing: Type 88 Instantaneous fuze (Howitzer, mortar type).

Operation and Employment: This round is used principally as an anti-tank weapon

Used in: Type 92 Infantry Gun (Howitzer)

Remarks:
The use of the white band above a yellow band to identify a hollow charge projectile is assumed to be a combination of the use of white band for armor piercing and yellow band for high explosive in the new color system. Both bands are near the middle of the projectile.

This arrangement is not to be confused with the combination of yellow band above white band to identify high explosive projectiles in the old color system, in which case the yellow band is at the bourrelet and the white band is just above the rotating bang.




Type 95 7cm (70mm) Illuminating Projectile

Weight of complete round: 4.20kg
Weight of projectile (Fuzed): 3.50kg
Weight of filling: No Data
Diameter at bourrelet: 70mm
Length of projectile (w/o fuze): No Data
Length of propellant case: 101mm
Length of assembled round (w/o fuze): 292mm
Diamater of base of case: 81mm
Width of rotating band: No Data
Filling:
-Ejection charge: Black Powder
-Illuminating composition: Not known. It is probably a mixture of magnesium, aluminium, and barium nitrate which is used commonly by the Japanese for illuminating charges.

Fuzing: Type 89 small time fuze

Propellant: 0.6mm square flakes (50g). Either of the propellant cases discussed for the H.E. round may be used for this round.

Used in: Type 92 Infantry Gun (Howitzer)

Remarks:
The illuminating charge burns for approximately 20 seconds with an intensity of about 90,000 candlepower



Type 92 7cm (70mm) High Explosive Projectile

Weight of complete round: 4.42kg
Weight of projectile (Fuzed): 3.81kg
Weight of filling: 0.59kg
Filling:
-Standard: Cast TNT
-Alternate: Pressed mixture of RDX and ammonium nitrate
Diameter at bourrelet: 70mm
Length of projectile (w/o fuze): 234mm
Length of propellant case: 101mm
Length of assembled round (w/o fuze): 306mm
Diameter of base of case: 81mm
Width of rotating band: 10mm

Fuzing: Type 88 short delay nose fuze (Gun type)

Propellant: 138g of 5mm square grain smokeless powder

Used in: Type 94 Tank gun

Remarks:
The projectile is the same as the Type 92 H.E. projectile used in the Type 92 Infantry Howitzer.



Type 95 7cm (70mm) Armor Piercing Projectile

Weight of complete round: 5.04kg
Weight of projectile (Fuzed): 4.45kg
Weight of filling: 0.17kg
Filling: Preformed paper-wrapped filling - Forward portion, "OSHIYAKU" (Picric Acid 90%, Paraffin 10%) - After portion, TNT
Diameter at bourrelet: 70mm
Length of propellant case: 101mm
Length of assembled round: 307mm
Diameter of base of case: 81mm
Width of rotating band: 10mm

Fuzing: Type 95 small A.P. base fuze

Propellant: 5mm square grain - 120g

Used in: Type 94 Tank gun


Next Time: An introduction to the Army's 75mm projectiles (And why you shouldn't label 70mm and 75mm rounds as "7cm")