Monday, 25 July 2016

Italian Explosive Ordnance - Projectiles (Introduction)

Italian Explosive Ordnance

Italian Projectiles and Cases


The projectiles used by the Italian army were very similar to French, British, and Japanese in construction and appearance.  In some cases, the projectiles were direct copies of British ammunition and used the same fuzing and filling.

Most field equipment is semi-fixed, with the smaller caliber and anti-aircraft guns using fixed ammunition.  When the semi-fixed type of ammunition is used, the propellent charge is divided into a number of parts which are enclosed in silk bags.

The first part is known by the Italians as the "fundamental," and the other part as "augmentative."  Igniters of black powder are also included.  The complete charge is enclosed in the cartridge case by means of a cardboard closing cup.  In the base of the cases are fitted percussion primers of standard design.

In guns using bag ammunition, an igniter, which has an extension piece fitted into the vent hole, is used.  For initiation of the charge, the types of tubes used are; friction, percussion, and electric-percussion.

The Italians designated their projectiles by the caliber, the specific equipment in which they were used, and the model numbers of projectiles.  In most cases, the model number is thought to have designated the year in which the ammunition was designed.

Types of Projectiles

1. High-Explosive (H.E.): These are of conventional design and are usually fitted with a point detonating fuze, with a booster charge below the fuze.  They most commonly have a shell body of forged steel and a parallel-wall inner cavity.  The cavity and exterior are machined over-all.  The cavity is threaded internally at the top to receive the nose adapter.  The latter is a machined forging, internally threaded at the nose to receive the fuze, and externally threaded at the base for attachment to the shell body.

In the medium caliber shell, the nose, contrary to the usual Italian practice, is sometimes formed by the "bottling" process with the upper portion threaded to take the fuze.  Another common method of construction is that which incorporates a shell machined from rolled bar steel and having a parallel-walled cavity of the same diameter as the nose adapter, or, in some cases where there is no adapter, the cavity is the same diameter as the fuze.

Some H.E. projectiles were cast and then machined.  The base plates of these shells also vary.  Some have no base plate, while others have the screwed type, the pressed-in type, or a steel plate soldered to the base of the shell.  The majority of the projectiles have on rotating band of pure copper, but a few have two rotating bands.

The booster system is of two types.  The first, the old system, consists of a metal tube containing compressed ballistite with a flash hole at each end.  This tube fits beneath the nose fuze and has underneath it a larger charge of ballistite, which is also in a metal tube and has a flash hole at the top only.

The latest type of booster system was designated "Detonatore AD Alto Explosivo" by Italians and was given the numbers 1 through 6, and called M35 or M38.  It consists of two parts, the upper part which fits immediately below the fuze and consists of an aluminum cylinder with a collar.  Inside this is another tube which contains a layer of cyclonite above which is a layer of lead azide.  Below this part is the other, which consists of two or more cylinders of TNT wrapped in oiled paper.  The upper cylinder has a central cavity to take the upper detonator tube.
2. Hollow Charge (E.P. and E.P.S.): A large range of artillery weapons are found to have been equipped with hollow charge ammunition.  Of the type that have been recovered, all show a similarity of design.  They appear to be converted H.E. shells.

The body of the shell is the same as that of the corresponding H.E. shells.  The almost hemispherical head is made of light alloy and, to overcome the difficulties in direction of rifling of different equipment, the head is secured to the body by indentation.  The nose portion of the shell is hollow and has a cavity liner pressed from 1mm steel plate, parabolic in shape.

There are two types of these shells, one using a base fuze only (E.P.) and the other, the late type (E.P.S.), incorporating a nose fuze with long flash tube leading to the center of the explosive charge.  this follows the German design.  The rotating band is usually located about 1/3 the distance from the base of the shell.  The explosive filling consists of 58% cyclonite, 40.5% TNT, and 1.5% wax.  The filling is cast with the fuze and booster assembled in the cavity.

3. Fragmentation: This type is also very similar to the H.E. projectiles, but contains a liner which fits into the internal cavity.  In most cases, the combustion type of time nose fuze is used.  The shell body is of forged steel with a comparatively thin wall, and is fitted with a copper driving band.

The forward end is screw-threaded internally to receive the adapter.  The body contains a fragmentation cylinder machined from grey cast iron, which is grooved along its length and circumferentially on the exterior to assist fragmentation.  A channel is formed through the center of the cylinder to accommodate the bursting charge.

Red lead is inserted between the exterior of the cylinder, the wall of the shell, and the fragmentation grooves.  The nose adapter is machined from grey cast iron and is screw-threaded internally to two diameters to receive the booster and the fuze, respectively.  The exposed portion of the adapter forms the head of the shell and is shaped to form a sloping shoulder with a cylindrical neck.  The base of the adapter is recessed to fit over the forward end of the explosive filling.  From tests, it has been found that the break up of the fragmentation cylinder generally follows the line of weakness. 
4. Armor Piercing (A.P.): Most Italian armor piercing shells are conventional in design.  The shell is generally machined from steel bar stock and then hardened from the rotating band forward.  A ballistic cap may or may not be fitted.  All but a very few have small explosive filling of TNT and a base fuze.

5. Shrapnel: The later type is designed on conventional lines.  It differs from the British type in having gunpowder pellets in the central booster tube.  An earlier type had a charge of TNT in the nose.  The shell has a nose adapter, a flash tube to the explosive filling located in the base of the cavity, and a diaphragm separating the explosive filling from the shrapnel bullets.

The shell body is forged steel and is machined externally.  The explosive cavity and bearing surfaces of the diaphragm are also machined.  The nose adapter, which forms a cover for the shrapnel bullets and provides a slot for the flash tube, is machined from bar stock.  The flash tube is of brass and fits between slots in the nose adapter and diaphragm.  The diaphragm is stamped steel plate.  The shrapnel bullets, varying from 100 to 250 in number, are lead-antimony alloy. 

6. Aerial Burst or Impact (A.D.E.): Projectiles designated "A.D.E." are regular High Explosive shells but have the A.D.E. type fuzes, which are time or percussion fuzes.

7. Anti-Aircraft (A.A.): These projectiles are H.E. shells with an aerial burst fuze.


Before 1931 the following coloring system was used:

Color of Body

Grey ----- H.E.
White ----- High Capacity H.E.
Blue ----- Fragmentation
Carmine ----- Shrapnel

Color of Nose (Ogive same color as body)

 Red ----- Practice Shell
Carmine ----- Star Shell
Black ----- Tracer

Color of Ogive

Red ----- H.E. or A.P.
Carmine ----- Incendiary
Black ----- Smoke
Yellow ----- Chemical

Since 1931, the shell body has been zincated and the ogive and nose painted in distinctive colored bands may be found on the body of the shell.  The following coloring scheme was used:

Color of ogive or nose same as before 1931

Band above the Rotating Band
Green ----- Steel shell
White ----- High Capacity H.E.
Red ----- Shrapnel
Blue ----- Fragmentation
Black ----- Practice

Band at Shoulder

Blue ----- Anti-Aircraft

The stenciling of which the following examples may be found on the body of the projectile:
100/17 - Caliber/length of weapon in calibers
Tritolo - Explosive Filling
61.000 kg - Weight of Projectile
A.P. VIII 1928 - Place and date of filling
Explosive Filling
The following explosive fillings have been found used by the Italians.
Italian Nomenclature
1. Tritolo - TNT
2. PNP - Ammonium Nitrate (75%), PETN (20%), Wax (5%)
3. MAT - Picric Acid (60%), TNT (40%)
4. MBT - Picric Acid, Dimitrophenol
5. Pertite - Picric Acid
6. Schneiderite - Ammonium Nitrate (87%), Dinitronapthalene (13%)
7. Nougat MST - Ammonium Nitrate (50%), Dinitronapthalene (7%), TNT (43%)
8. Toluolammonal - Ammonium Nitrate (47%), TNT (30%), Aluminum (20%), Carbon (3%)
9. MNDT Siperite - Ammonium Nitrate (72.8%), Dinitronapthalene (10.5%), TNT (16.7%)
10. Amathol Explosive 60/40 - Amathol
11. Ecrasite - Ammonium Triniteocresol
12. Tritolite - TNT (50%), Cyclonite (50%)
The composition of the propellants has no outstanding features.  Apparently only three types were used in service:
1. A straight ballistite (Ballistite or Bal.) containing about 50% nitro-cellulose and 50% nitroglycerin without stabilizer.
2. A modified ballistite (Ballistite Attenuate or Bal. Att.) containing 60% nitro-cellulose, 26% nitroglycerin, and 14% dinitroluene as a moderant coating.
3. The so-called "Italian Cordite" which usually bears no markings other than the weapon and propellant sizes.  This contains about 72% nitro-cellulose, 24% nitroglycerin, and 4% mineral jelly.  In addition, this type of propellant has been found to contain sodium carbonate or bicarbonate, presumably as an additional stabilizer.
In some cases, bags containing potassium chloride have been found included in the charges, presumably as a flash-reducing agent.  The shapes encountered have been flat strip, cord, square flake, and tubular cord. 
An example of marking of the propellant is:
"Ballistite Attenulata Piastine - 1 x 10 x 220 days CKA VI grs. 570" 
The marking reads it as a charge of 570 grams of "Ballistite in Attenuata" strip form 1mm x 10mm x 220mm for the 75mm gun.

Naval and Coastal Defence Equipment

The equipment is simpler to design as the Army but different distinctly in markings from Italian field equipment.  The following coloring is used:

H.E. --- White body with red ogive
Star --- White body with red ogive
Practice --- Yellow with grey and white nose

Special light projectiles, as opposed to heavy projectiles, have green bodies and white heads (grey if made of cast iron).

Star --- Green band above the rotating band
A.P. --- Blue band above the rotating band
Practice H.E. --- Yellow band above the rotating band
A.P. Shot --- Red band above the rotating band

(Piercing caps - Red; Ballistic caps - Unpainted)

The markings on the H.E. projectiles are:

On the body - Caliber and filling
On the ogive - Type, date, and place of filling
C.L. - Tracer fitted

Star shells have a black triangle on the ogive which may or may not enclose a black disc.  This refers to type of star filled.

Next Time: Italian Small Arms Ammunition

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