American Projectiles and Explosives - Rocket Bodies, and Navy Rockets (Part 1)

American Projectiles and Explosives

Rocket Bodies Introduction

General

 The propelling unit of the rocket is called the motor and contains the propelling charge.  The motor is attached to the head, which contains the payload and the initiating device.  The motor is closed on the forward end and partially opened at the after end.  The propellant is a relatively slow-burning double-base smokeless powder called ballistite.

As the ballistite is burned, hot gases are generated which expand and exert pressure against the confines of the motor tube.  Since the hot gases exert an equal pressure in all directions, the pressures against the side walls counter-balance each other; however, the pressure against the forward closed end of the tube is not counteracted by pressure against the after end since that end is partially open.  The resultant force, then, is a thrust against the closed forward end of the motor, and the rocket is propelled in that direction.  In order that the pressure of the gases will not be expended too rapidly, and that the propellant can be retained in flight, the after end of the motor tube is partially closed by the nozzle attachment, which is built into the inside of the tube.  This nozzle restricts the ejection of the hot gases and also, by means of its rear taper, furnishes a canted surface against which the rapidly expanding emitted gases may act to increase the forward thrust of the rocket.

The ballistite propellant is ignited by a black-powder charge, the initiating device for which is an electric squib with a small bridge wire of high resistance which, when heated by an electrical current, ignites a violent match composition.  The black powder charge sends a flash over the entire surface of the ballistite to the ignition point.  Upon ignition, the ballistite burns evenly and relatively slowly; this type of burning is necessary to prevent sudden and excessive pressures being exerted against the thin walls of the motor tube.  Rocket motors operate at much lower pressures than guns, and correspondingly longer times are required for the complete combustion of the rocket propellant.  Burning times of American rockets range from about 0.15 seconds to as much as 1.5 seconds, depending on the web thickness of the grain and the temperature of the propellant; and burning distances range from a few feet to several hundred feet at high velocities; hence, most of the burning of the rocket propellant occurs after the projectile has left the launcher.

The early productions of rockets were of the fin-stabilized type because of their use by the British and because of the inherent simplicity associated with fin stabilization.  Rockets cannot be launched with that degree of accuracy characteristic of gun projectiles.  This is a result of many factors, such as the effect of temperature on the burning rate of the propellant, difficulties in controlling to a fine degree the pressures exerted by the expanding gases inside the motor tube, the effect of the expansion of emitted gases against the rear taper of the nozzle, etc.  The mean deviation in deflection for most standard land- or shipboard-launched fin-stabilized rockets is 20 to 40 mils, while fin-stabilized rockets launched from aircraft have a mean deviation of about 5 to 10 mils.  The increased accuracy of aircraft-launched rockets is attributed to the immediate stabilizing effects given to the fins during the initial stages of flight by the rapid travel of the plane through the air.  Fins on rockets exert an appreciable restoring force in flight only at a high velocity, and thus a greater degree of accuracy is achieved if rockets are launched from aircraft or if the acceleration occurs to a large extent on the launcher.

A later development, the spin-stabilized rocket, is now in service use.  Stabilization of this rocket depends on the rotation of the round.  Although the accuracy of spin-stabilized rockets is not comparable to that of gun projectiles, they are generally more accurate than fin-stabilized rockets at short ranges.  The use of spin-stabilized rockets will be particularly advantageous to ground and amphibious forces, inasmuch as the rocket is shorter and the launching gear is more compact, facts which facilitate the loading and stowage problems.

As against their disadvantages, rockets have many advantages over gun-propelled projectiles.  The most important is the absence of recoil against the launcher.  Since there is no recoil action on the launcher, rockets may be launched from small trucks, amphibious ships, and aircraft which could not withstand the recoil forces exerted by equivalent projectiles fired from guns.  Other advantages of rockets are cheapness, simplicity, and portability of the launchers as compared to guns.

Components



Head: This is the part which is functionally similar to a projectile and which contains the payload and the initiating device.  This payload may be solid shot, high explosive, chemical, incendiary, window, flare, or a special load.


Motor Tube: This contains the propelling charge and the igniter.  It is a combustion chamber in which the propellant is burned to provide the motive power for the rocket.  It generally threads to the rocket head and is usually shipped separate from the head and fuze.  The diameter of the motor is generally less than the diameter of the body with which it is used.


Grid or Trap assembly: The Navy refers to the assembly which supports the powder grain as the grid.  This grid supports the grain in such a position that sufficient clearance is allowed between the grain and the motor tube to allow the gas to flow from the propellant to the nozzle.  The Army uses a trap assembly, which is somewhat more complicated than the Navy grid.  The trap assembly consists of spacing discs and wires running between them, on which the sticks of ballistite are supported.  Such an assembly is necessary where numerous small grains are used.


Nozzle: The number of nozzles varies with the type of motor and method of stabilization.  The nozzle has several functions.  It directs the gas jet in the desired direction and provides for expansion of the hot gas in the exit cone, thus giving additional thrust (about 33%) over the obtainable from a simple orifice.  In spin-stabilized rockets, it imparts a clockwise rotation tot he rocket when launched.


Fins: During burning, the action of the air against the fins gives a restoring moment against side forces at the nozzle, thus improving the accuracy of fire.  When there is a tail shroud, it supports the rear end of the rocket in the launcher and may also provide electrical contacts for firing.


Propellant and igniter: The igniter contains loosely packed black powder and an electric squib with a high-resistance bridge running through a match composition.  The propellant is a double-base smokeless powder called ballistite, which burns slowly and uniformly.  Production of ballistite differs somewhat for the Army and the Navy, the Army preferring the solvent extrusion process and the Navy specifying the solventless extrusion process.  The solvent extrusion process is impractical for grains having a web of more than 1-1/4 inches.

Grain shapes also vary.  Army rockets generally have several small cylindrical grains of ballistite, with an axial hole to increase the burning surface and uniformity of burning.  The Navy rockets use either a single solid cruciform grain without perforation or a single cylindrical grain with an axial hole and radial perforations.  The latter, used in Navy ground- or shipboard-mounted rockets, is characterized by three ridges 120 degrees removed and running longitudinally along the grain.  Inhibitors are not used on this type.  The cruciform grain, in Navy aircraft rockets, is a symmetrical cross with rounded ends.  If all the exterior surface of this grain were permitted to burn, there would be a gradual decrease of area, and a regressive rate in burning.  Hence, a number of slower burning cellulose acetate strips are bonded to parts of the area exposed on the outer curved ends of the arms, to give desired burning characteristics.


Storage:  To decrease hazards in handling, rocket bodies and motors are generally shipped and stored separately.  Motors with large grains are kept in a non-propulsive state until final assembly is necessary.  The seals at both ends of the motors are light and easily displaced by pressure developed inside the tube.  Should the igniter and grain igniter, the closures would fail quickly, relieving the pressure without more than a slight movement of the motor.

It is necessary that loaded motors be kept at moderate temperatures as much as possible.  Event hough spontaneous ignition should not take place, the powder should not be stored where temperatures exceed 100 degrees Fahrenheit, because such conditions tend markedly to decrease the stable life of the propellant.  Because of the electric squib, rocket motors should not be stored near radio apparatus or antenna leads.

Although there is very little possibility of a motor firing as a result of falling or rough handling, such treatment is likely to cause malfunctioning of the rounds.  Ammunition should be kept in packing containers or ready boxes and should not be handled in a loose condition unless necessary.

Practice Rockets

Practice rockets are loaded with plaster of paris or other inert substances to simulate the explosive loads in service rounds.  These rockets also have dummy fuzes.




Safe Temperatures

The burning rate of propellent powders changes with temperature and pressure - the higher temperatures and pressures causing more rapid burning.  If rockets are fired at temperatures higher than those for which they are designed, the pressure may build up faster than the nozzle can release it, perhaps bursting the round.  At temperatures below the safety limit, there will be back blasts of flame with burning fragments of powder.

Retro Rocket

These were rockets designed to be fired aft from a fast moving ship or plane - the movement aft to compensate exactly for the movement forward of the launching vehicle, thus leaving gravity as the only effective force on the rocket.

2.25-inch A.R. Practice

General: The 2.25-inch sub-caliber rocket rocket for aircraft was developed for training purposes.  Initially, two types were designed to approximate the trajectory of the 3.5-inch and 5-inch rockets; however, only the Motor Mk 11 and the Head Mk 3 Mod 2 will be used in future training.

The Mk 1, a California Institute of Technology production, was issued until adopted and issued by Bureau of Ordnance as the Mk 3 Mod 2.  The Mk 2, a California Institute of Technology production, was designed as a slow sub-caliber rocket.  The complete assembly for the latter is no longer available.

The 2.25-inch Motors Mk 10 and Mk 11 are similar to each other, as are the 2.25-inch Motors Mk 12 and Mk 13.  The Motors Mk 10 and Mk 11 differ from the Mk 12 and Mk 13 in that the diameter of the nozzle on the latter is smaller and the weight of the propellant of the Mk 10 and the Mk 11 is 1.75 pounds, as compared to the weight of 1.12 pounds in the Mk 12 and Mk 13.

The external dimensions of the rockets are the same.  For recognition purposes, the 2.25-inch motors Mk 10 and Mk 11 are painted white with black fins, while the Motors Mk 12 and Mk 13 are grey with black fins.


Motor Mk 11 and Head Mk 3 Mod 2: Overall length of the rocket is 29 inches.  Two button-type lugs are provided ont he motor tube, spaced approximately 19 inches apart.  Four fins are welded to the after end of the motor tube.  The propellant is a cylindrical grain of ballistite weighing approximately 1-3/4 pounds.

3.25-inch Targets

General: As a target for anti-aircraft gunners, the rocket is projected with speeds approximating those of an aircraft.  It consists of a rocket propulsive unit to which are attached large stabilizing fins, for maximum visibility.  They all consist of a simple rocket motor with three large fins prepared from wooden frames and light-weight fiber board.  The fins are 120 degrees apart, each attached by two lugs.

The 3.25-inch Rocket Targets Mk 1 and Mk 2 consist of a motor 36 inches long, to which fins 18 inches by 34 inches are attached.  An electrical connection is made by a standard 110-volt plug.  The 3.25-inch Target Rocket Mk 1 is standardized at 425 mph and the Mk 2 at 300 mph.  On some models, a screamer is put over the nose end.

The Mks 3 and 4 differ from the Mks 1 and 2 in that the motor is heavier and the fins are held on by threaded studs instead of lugs.  The ballistics are similar; Mk 3 is like Mk 1, and Mk 4 is like Mk 2.

Next Time: Navy Rockets (Part 2)

American Projectiles and Explosives - Projectiles and Types

American Projectiles and Explosives

United States Projectiles (and their Types)





Armor-Piercing

These projectiles are designed to penetrate an equal caliber of Class A armor plate, according to test practice.

The characteristics:
-Overall Color: Black
-Sizes: 3", 6", 7", 8", 12", 14", 16"
-Explosive Filling: Explosive D
-Load Factor: 1.5% to 2.7%
-Fuzing: Base detonating or base ignition

Since it is desirable to keep the center of gravity of a projectile to the rear of (or in the immediate vicinity of) the center of the form, and as a relatively long ogive is conducive to long range, it has been advantageous to adopt light nose pieces or false ogivals termed windshields.  The windshield is made of either forged mild steel, steel stamping, or aluminum.  It has no special strength other than to prevent destruction during handling and set-back on firing.  Windshields are screwed to the cap and are "set" by a center punch.

The armor-piercing cap is secured to the projectile by peening the skirt of the cap into notches cut into the ogive of the body and by soldering the cap to the body with a special solder of low melting point.  Such solder prevents the soldering heat from drawing the temper of the body.  Caps are made, in general, of the same kind of steel as are the projectile bodies.  The cap acts to break down the initial strength of the armor plate, allowing the nose to reach an already strained surface.  It also provides powerful circumferential support to the point and nose as they begin to penetrate the hard face, maintaining the support until they are will into the plate.  In addition, the characteristically blunt outline of the cap serves to increase the effective angle of obliquity at which the projectile may hit and still penetrate.

The body is of high-quality alloy steel, carefully forged and heat-treated, since it is the part which does the actual penetration.  Between the forward bourrelet and the rotating band or rear bourrelet, the diameter of the body is slightly reduced in order to provide a general clearance from the bore of the gun.  The bourrelet is the bearing surface of the projectile and rides the lands of the rifle.  This bearing surface is usually about one-sixth caliber in width, and its surface is generally ground to a fine finish to reduce friction and minimize wear on the lands of the gun.  With the major caliber projectiles, it has become standard practice to provide a rear bourrelet or bourrelets in addition to the forward bourrelet.  Rear bourrelet or bourrelets will be just before and behind the rotating band, providing better support in the gun and during the moment of ejection at the muzzle.

The rotating band has three primary functions: to seal the bore, to position and center the rear end of the projectile, and to rotate the projectile.  A secondary function is to hold the projectile in place during loading and elevating for firing.  The rotating band is made of commercially pure copper, or of cupro-nickel alloy containing 2.5% nickel, or in some cases a gilding metal consisting of 90% copper, 10% zinc.  As a general rule, rotating bands are about one-third caliber in width.

The base plug closes off the explosive cavity and holds the base fuze or base fuze adapter.  Both the base plug and the base fuze adapter, if used, are sealed in place with a gas seal ring similar to that used on the base fuze.

The base fuze is inserted through the base plug or base fuze adapter and is designed to detonate the projectile after penetration.  After insertion, it is closed with a gas check ring of copper and lead put in under hydraulic pressure to prevent the propelling gases from affection the explosive filling.

Armor-piercing projectiles and common projectiles having a windshield may carry a spotting dye which colors the water on impact in order that observers may spot the fall of shot.  The spotting dye in powder form is placed in the windshield before it is screwed on to the nose of the projectile.  Water forces through the inlet holes covered by copper covers, dissolves the dye, and forces it out the outlet holes.






Special Common

The term "Special Common" is not an official designation of the Bureau of Ordnance, which places this and all other types of Common projectiles in a single class.  The "Special Common" term, however, is widely employed by ordnance activities to describe those Common projectiles which are equipped with both windshields and hoods for windshield attachment.

These projectiles are designed to penetrate approximately one-third to one-half their caliber of armor.  These projectiles differ from Armor-Piercing projectiles in that they do not have an armor-piercing cap and have a larger explosive cavity.

The characteristics:
-Overall Color: Slate Gray
-Sizes: 4", 5", 6", 8"
-Explosive Filling: Explosive D
-Load Factor: 2.1% to 3.99%
-Fuzing: Base detonating





Common

These projectiles are designed to penetrate approximately one-third their caliber of armor.  They differ from Armor-Piercing and Special Common projectiles in that they have no cap or hood; the windshield threads directly to the body.  Also, the explosive cavity is slightly larger.

The characteristics:
-Overall Color: Slate Gray
-Sizes: 5", 6", 8"
-Explosive Filling: Explosive D
-Load Factor: 4.4% to 5.4%
-Fuzing: Base detonating

Old Types

In addition to these Special Common and Common projectiles described above, certain types of old Common projectiles are still in use in the Naval service.  These projectiles have neither cap nor windshield, are colored slate overall; are loaded with Explosive D or black powder/TNT mixture.  In the latter case, they are fuzed with a base ignition fuze.  This latter type is found in the 1-, 3-, and 6-pounder projectiles and in the 3-, 4-, and 5-inch sizes.




High-Capacity

These projectiles are designed to have a minimum wall thickness, and the largest explosive cavity consistent with the force of set-back.  They are assembled, generally, with no-delay base fuzes, tracers, steel nose plugs, and auxiliary detonating fuzes.  The steel nose plug may be removed and a point detonating or nose time fuze substituted.  These projectiles are used for shore bombardment, for anti-aircraft guns, and for use against light ships and surface craft.  The 3-inch High-Capacity has no base fuze.

The characteristics:
-Overall Color: Green
-Sizes: 3", 4", 5", 6", 8", 12", 14", 16"
-Explosive Filling: Explosive D, except the 3", which is TNT loaded
-Load Factor: 7% to 12.6%
-Fuzing: Only variation from the no-delay base fuzes is the Base Detonating Fuze Mk 48, with a 0.01-second delay, currently being assembled in 8" through 16" H.C. projectiles for bombardment.  In the 12", 14", and 16" H.C. projectiles, there is a TNT booster beneath the auxiliary detonating fuze, requiring an addition adapter ring.



Anti-Aircraft Common

These projectiles are similar in construction to H.C. projectiles, except that a nose time or V.T. fuze is always assembled.  It ca be used for anti-aircraft fire or, with the time fuze set on safe, used for bombardment.

The characteristics:
-Overall Color: Green
-Sizes: 5-inch only
-Explosive Filling: Explosive D or Composition A
-Load Factor: 13%
-Fuzing: Nose time or V.T. fuze.  Auxiliary detonating fuze.  No-delay base detonating fuze.




Anti-Aircraft

These projectiles vary from Anti-Aircraft Common in that no base detonating fuze is used.

The characteristics:
-Overall Color: Green
-Sizes: 3-inch only
-Explosive Filling: Composition A or TNT
-Load Factor: 5.7%
-Fuzing: Nose time fuze, auxiliary detonating fuze

Illuminating

These projectiles are for illuminating targets by a parachute flare.

The characteristics:
-Overall Color: Light Blue with two white stars
-Sizes: 3", 4", 5", 6"
-Explosive Filling: Black Powder expelling charge
-Fuzing: Nose time fuze only


The illuminating projectile is a thin case with a very small expelling charge just behind the fuze and an interior assembly of a star or candle with a parachute and a very lightly held base plug.  Explosive of the expelling charge forces out the base and the interior assembly.

When the nose time fuze functions, it ignites the black powder expelling charge, which in turn ignites the star or candle.  The star or candle is a steel container in which is packed under heavy pressure an illuminating compound.  The closed end of the star container is attached to the strand wires of a parachute.  The parachute is carefully folded, and, with its strand wires, is rolled so that upon expulsion it opens, thereby suspending the candle or star.

Because of the high velocity at which the projectile is travelling when ejection takes place, it is necessary to slow down the star-parachute assembly before the parachute becomes fully open.  This is done by a center wire, one end of which secures the center of the parachute nearer to the star than when the parachute is in full release and causes the parachute to spill air, thereby preventing too great an initial strain on the parachute,  After the star has burned for a few seconds, the end of the center wire is released from its point of attachment in the star can.  This permits the parachute to open fully.

Window

Window projectiles are designed to be fried from naval vessels to disrupt enemy radar operations.  The projectile may be used to provide a false screen behind which our ships may maneuver or approach undetected, or to provide a false target for enemy radar.  The projectile itself consists of an illuminating projectile body fitted with a nose time fuze and an expelling charge of black powder.  Ignition of the expelling charge by the fuze discharges a payload of foil strips which form a reflecting cloud of radar beams.

The characteristics:
-Overall Color: Aluminum
-Sizes: 5-inch only
-Explosive Filling: Foil strips and black powder expelling charge
-Fuzing: Nose time fuze

White Phosphorus (Smoke)

Smoke projectiles are designed for shore bombardment purposes to produce a combination of screening, anti-personnel, and slight incendiary effects.  These projectiles may also be used at sea to provide a surface screen behind which vessels may maneuver undetected.  The projectile consists of an illumination projectile body, fitted with a nose time fuze or point detonating fuze and a black powder expelling charge.  The ignition of the expelling charge by a fuze discharges a number of white phosphorus filled steel tubes which ignite on contact with the air.

The characteristics:
-Overall Color: Blue Gray
-Sizes: 5-inch only
-Explosive Filling: White Phosphorus and black powder expelling charge
-Fuzing: Nose time or point detonating fuze

V.T.-fuzed Projectiles

These projectiles are specially cavitized to receive the long-stemmed V.T. fuzes.  They contain no tracer or nose fuze adapter, and no base fuzes are used except with the 6"/47 H.C. Projectile Mk 34.  In all others, the base is sealed with a gas-checked base fuze hole plug.  Other than V.T. type nose fuzes may not be employed in these projectiles.  New V.T. fuzed projectiles are being filled with Composition A.

The characteristics:
-Overall Color: Dependent on type of projectile that is V.T.-fuzed.  But, on all new projectiles, the letters V.T. are painted on the band showing the explosive filler
-Sizes: 3", 5", 6"
-Explosive Filling: Composition A is being loaded in the new V.T.-fuzed projectiles

Target Projectiles

These projectiles are inexpensive productions, with ballistic traits similar to the A.P. projectiles of their caliber.  They are unfuzed and contain no explosive.  On some types, a dye is loaded into the windshield, which on impact with the water is funnelled out and spread through the water splash, thus distinguishing the origin of the salvo.

The characteristics:
-Overall Color: Red
-Sizes: 6", 8", 12", 14", 16"

Gas

The same type of projectile that is used for the smoke round may be loaded with gas for chemical warfare.

Limited-use Types

Field and Bombardment: These projectiles were designed for field use or shore bombardment.  They carry point detonating fuzes.

Shrapnel: Shrapnel projectiles contain steel balls which are expelled from a shrapnel case by means of a small charge of explosive, the case remaining intact.  These projectiles are obsolescent.

Flat Nose: Flat nose projectiles are for use against submarines, and are designed to prevent ricocheting on water impact.  These projectiles are obsolescent.

Tracer: These are special projectiles designed solely to leave a visible trace int he daytime.  They do not have bursting charges.  These are obsolescent.

Proof Shot: These are special projectiles designed not to ricochet on water impact and are for use in proving-ground work.  It is not contemplated that more of these projectiles will be procured when the present stocks are exhausted.

"Pounder": These are for Coast Guard guns.

Next Time: Minor calibers: Colors, markings, and more

German Projectiles - Introduction and Colour and Markings System

German Projectiles





Introduction to German Artillery Projectiles



Classes of German Artillery Ammunition

Class #1: (Fixed Ammunition) Ammunition, the complete round of which, can be loaded into the weapon in one operation.  The cartridge case, containing a primer and propelling charge is permanently crimped to the projectile.


Class #2: Ammunition, the complete round of which, is loaded in two operations.  The cartridge case, containing a primer and a propellant charge is not crimped to the projectile.  The propelling charge is in bags and the charge can be varied at the point of firing.  The projectile is packed and shipped separately, and the cartridge case and propellant are packed as one unit.


The Germans employ cartridge cases in all their artillery ammunition.  The cases are employed for the main purpose of preventing the escape of gas to the rear.

 Nomenclature

The Germans designate a round of artillery ammunition by the Caliber, Type of Ammunition, (Model No. of the round), Type of Weapon fired from, and (Model No. of the Weapon.)

The caliber of German Artillery Ammunition is measured in centimeters.  The Germans refer to calibers approximately; for instance, the 10.5cm gun is always known as the "s 10cm K.18", (Heavy 10cm Model No.18)

In naming the various types of projectiles, the Germans employ the word, "Granate", (abbreviated "gr." or "Gr.").  "Granate" is used as a base word for all the various types of rounds.  By adding a prefix and/or a suffix to the word, the exact nature of the projectile is indicated.



Prefix added to the word "Granate"

(In order to differentiate between the various types of Armor Piercing Rounds, numbers are added after the word Pzgr.)

Panzergranate 39 -- Pzgr. 39 -- APCBCHE (Armor Piercing Cap, Ballistic Cap [windshield] High Explosive)

Panzergranate 40 -- Pzgr. 40 -- A.P. Shot with a tungsten carbide core

Panzergranate 41 -- Pzgr. 41 -- A.P. Shot with a tungsten carbide core for tapered bore gun (Gerlich gun)

Sprenggranate 41 -- Sprgr. 41 -- H.E. Shell for a tapered bore gun



Suffix added after "Granate"

For the most part the Germans do not give Model Numbers to their artillery ammunition.  In several of the old rounds Model Numbers are indicated.  The numbers used are the lat two of the year in which the round was made standard.  These are only used in the nomenclature when there is more than one model of any specific type.  In the case of the "Pzgr." (Armor Piercing) rounds,  the numbers appearing after the word merely indicates the type of Armor Piercing round and are not Model Numbers.


Rot. or L'spur. (Leuchtspur) included int he designation indicates tracer.

This nomenclature is followed by the word "Patronen" abbreviated Patr., meaning cartridge.  This is the German way of indicating a complete round.  It is similar to the British nomenclature, in that the British use the word "cartridge" to designate all their complete rounds.

The Germans include the name of the type of the weapon in designating their ammunition.  This nomenclature is given in the form of an abbreviation.

 
In some instances a letter in parenthesis is added to the nomenclature after the word indicating the type of projectile.  These letters are used to indicate material of foreign origin.  The following are some of the letters used for this purpose.

(t) Czech
(f) French
(p) Polish
(r) Russian
(o) Austrian

In some cases the following may be included in the nomenclature:

German --- English
              NA --- New Pattern
        umg --- Modified
     St --- Steel


The following details of stencilling on projectiles are arranged in the sequence in which the markings are normally found commencing at the nose of the projectile.

Z.F.Hbgr - (In black) On the windshield of an H.E.B.C. shell indicates the use of a nose fuze under the windshield

R or Mr - (In black near the tip) Indicates the presence of a smoke box.

Arabic numerals - (In black on the head of the shell just below the fuze hole, or on the body of the shell), indicates the type of H.E. filler.  The more common of these are given below.

The following are some examples of German ammunition nomenclature.

4.7cm Sprgr. Patr. Pak (t) - 47mm H.E. Shell for the A.T. gun of Czech make.

3.7cm Pzgr. Patr. 40 Pak - 37mm A.P. Shot - Tungsten Carbide core for the A.T. gun.

7.62cm Pzgr. Patr. 40 Pak. 36 (r) - 76.2mm (3") A.P. Shot - Tungsten Carbide core for the A.T. gun 36 (Russian design).

8.8cm Sprgr. Patr. Flak 36 - 88mm H.E. Shell for the Anti-Aircraft gun 36.




Color of the Projectile

 
Projectiles of the latter type are sometimes painted white.  This color appears to be used for projectiles in the experimental stage supplied for trial by the Army in the field.

Band marking is not common use except for a red band above the rotating band in some shells, indicating a tracer, and a yellow band for the 3.7cm aluminum colored H.E. tracer shell.

The place and date of the filling of the projectile, followed by a lot number in black, is on the shoulder of the projectile in the form of an abbreviation.

The Weight Zone of the projectile is indicated by Roman numerals, black in color near the bourrelet.

In the following instances the type of shell, and to some extend the nature of the filling, is indicated by 2.4" letters stencilled at two positions round the shell midway between the rotating band and bourrelet.

The place and date of assembly, followed by a lot number, are stencilled in 4" black or red lettering above the rotating band, e.g., "Lr 4.640L."



Stamping on the Projectile

The following are stamped on the ogive in the order in which they appear.

1.  Acceptace test number
2.  Delivery number, firm and year of manufacture
3.  Firm's proof mark


The following appear on the body of the projectile:

1. An acceptance stamp, water pressure test and an acceptance stamp, second test.
2. Acceptance stamp (Hardness).
3. Shell model number.
4. Delivery number, firm, year of manufacture, acceptance stamp of release.


The following appear on the base:
1. Delivery number, firm, year of manufacture.
2. Projectile model number.
3. Acceptance stamp for fitted base.
4. Acceptance stamp.




Identification of the Fixed Cartridge Case and Charges

  

  
Stencilling on side of Case


The following details are arranged in the sequence in which the markings are normally found between the approximate center of the case and flange at the base;

1. The caliber, types and model numbers of the weapons for which the round is suitable are stencilled in the form: 7.5cm KWK 40 (7.5cm, tank gun Model 40).  Where a round is suitable for more than one equipment, the designation of the equipment is stencilled in sequence with the letter "u" signifying "and" as a conjunction.

2. The weight of the propellant charge in grams is stencilled int he form of numerals, followed by the letter "g" below the nomenclature of the ammunition. (e.g. "164g")

3. The nature, shape and size of the propellant charge are stencilled below the marking indicating the charge weight.

The following markings are used to indicate the nature of the propellant

  [Note: My copy is either missing #4 and #5, or they don't exist.]

6.  The red stencilling used to indicate propellant charges of a reduced weight for hot climates may be found near the base of the case, just above the flange, or higher up the side of the case, above the other stencilling.  The marking used:  Tp ---- 25* C.  indicates that the normal or standard charge temperature on which the weight of the charge is based is 25 degrees Celsius (77 degrees Fahrenheit).  The German standard charge temperature for normal European temperatures is 10 degrees Celsius. (50 degrees Fahrenheit)

 7. In some instances cases are stencilled:  "Abgebr Ldg" in red.  This marking is found near the base (corresponding to the position of the Tp - 25* C. marking) and probably refers to the propellant charges of low stability which are to be give priority in expenditure.


Stencilling on the base of Fixed Cartridge Cases


Type of the projectile is stencilled in white or black to the left above the primer hole.

In some instances the Roman numerals indicating the weight classification of the projectile are stencilled in white to the right below the primer hole.


Stampings on the base of Fixed Cartridge Cases


Model number of case.
St. - after model number of case -- indicates a steel case.
Model, Cal. and type of weapon.
Manufacturer's Initial.
Delivery number.
Year of manufacture.


Markings on Cartridge Bags in Fixed Rounds


The markings are the same as those stencilled on the side of the case except that the caliber, type and model number of the equipment are not included.

Markings on Semi-Fixed Cartridge Cases


A cardboard or leatherboard cup is used to close the mouth of the cartridge case in a round where the cartridge case is packed separately.

A label, found on the closing cup, contains information corresponding to the stencilling on the side of the fixed cartridge case.  The information is as follows:

Details of the weapon.
Charge weight.
Kind.
Type (size and shape of the charge.)
Place and date of manufacture of propellant.
Place and date of filling.
Indication of propellant charges for hot climates.


Cases with steel covers for packing and transport, which are removed before loading, have neither labels nor stencilling relating to the propellant charge except the stencilling "Tp.25* C." imprinted on the base where applicable.  Details of the propellant are available, however, from the stencilling on the charge bags.

Stamping ont he base of the case is the same as that on the base of a fixed round, except that the caliber of the equipment is sometimes omitted.


Markins on the Cartridge Bags of a "Semi-Fixed" Round


These bags are marked similarly to the markings on fixed bags, except that the designation of the weapon is included.  In some cases the caliber is not included.  "Bleidraht im Beutel" indicates lead wire is included in the bag as a decoppering agent.

The number indicating the charge is marked prominently in black.  The letter "D" often follows this number and in some instances the marking is encircled by a red ring.


"Sonderkart" - Supercharge - With certain weapons additional charge sections, to be used for long ranges in place of those in the cartridge case, are supplied in cylindrical cardboard packages.  These sections are numbered in continuation of those supplied for use at normal ranges in the case.  Cardboard packages containing these additional charge sections are marked "Sonderkart" followed by the numeral of the section.


Marking of Primers for "Fixed" and "Semi-Fixed" Ammunition


Designation -- C followed by number.

Example: - C/33
nA - New Pattern
St - Steel


Marking of Flash Reducing Charges


This charge is found in a flat circular silk bag and is identified by the words "Kart. Vorl.", followed by the abbreviation indicating the weapon with which used and the weight of the charge in grams.

 

Next Time: 7.92mm to 30mm Projectiles

Italian Explosive Ordnance - Projectiles (Introduction)

Italian Explosive Ordnance

Italian Projectiles and Cases

Introduction

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.






Markings

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%)

    

    

    

Propellants

    

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

Soviet Explosive Ordnance - Markings System Part 1

 

Identification of Soviet Projectiles and Projectile Fragments (Part 1)

Markings System:

a. History - Prior to 1938 each Soviet munitions manufacturing arsenal and loading plant used its own system for identification markings.  The resultant lack of uniformity in markings created considerable confusion within the supply and using agencies. 

In 1938 the Soviets corrected this situation by adopting a uniform markings system and organizing the artillery supply system into three seperate departments.  Each department was made responsible for the supply of specified items of artillery and given a numerical designation; this department number is included in the official identification code for the artillery items for which the department is responsible, as explained in b below 

The three departments are listed below:

(1) Department 52.  The "Department of Artillery Equipments." Responsible for the supply of all artillery weapons, mounts, fire control instruments, and related equipment, excepting ammunition.

(2) Department 53.  The "Department of Fixed Ammunition, Projectiles, Fuzes, and their Packing."  Responsible for the supply of all fuzes, projectiles, and fixed complete rounds, as well as the packing for these items.

(3) Department 54.  The "Department of Charges and Cases."  Responsible for the supply of all powder bags and propellants, and all cartridge cases except those for fixed ammunition, as well as the packing for these items.

b. The Identification Code.  Identification codes are used in Departments 52, 53 and 54 in order to designate various artillery items briefly and, at the same time, clearly.  The codes follow a pattern common to all three departments, and may be distinguished from other markings by virtue of this pattern.  They consist of certain combinations of Arabic numerals and letters of the Russian alphabet, and may be full or shortened. 

The full code designation consists of three components, separated by dashes, which appear within the designation in the order named:

First, a group of two numerals, identifying the department responsible for the supply of the item concerned (a (1), (2), and (3) above);

Second, a group of one to four letters of the Russian alphabelt, designating the item by type; and

Third, a group of three numerals which identify the individual item or model, and which are sometimes followed by one to four Russian letters giving additional information on the item.

The shortened code is usually to be found on the item itself and consists only of the second and third components.  The omission of the first component from the shortened code is not apt to lead to confusion, since the supplying agency can generally be identified merely from observation of the item; for example, guns obviously fall under Department 52, projectiles under Department 53, and powder bags under Department 54.

In the following examples of both full and shortened code designation of artillery items, it should be borne in mind that: in most cases, the shortened code appears on the item and/or its packing; and that the same Russian letters have entirely different meanings when used by the different supply departments, or when in different positions within the same designation.

(1) Items under Department 52.

Full Code: 52-П-354

Shortened: П-354

52, the first component, identifies the supplying agency: Department 52.

П, the second component, designates the item by type: a gun.

354, the third component, identifies the model:

(35) means the item is a member of the 35th group of artillery weapons, which consists of 76mm guns - other than AA guns -

(4) means the item is a member of the 4th series of models in that group, the Model 1902/30.

Thus, the item is the 76mm Divisional Gun, Model 1902/30 - or one of the weapons having the same ballistic characteristics.

Note - Ballistically identical models of the same group are given the same code number; thus, "354" also denotes the 76mm Divisional Guns: M1942 (ZIS-3), M1936, M1939, M1942 (ZIS-2) and M1940

(2) Items under Department 53.

Full Code: 53-БП-354A

Shortened: БП-354A

53, the supplying agency: Department 53.

БП, the type of item: a HEAT (БП) projectile.

354A, the model: (354) for the 76mm Divisional Gun, Model 1902/30 - or its ballistic equivalent -

(A) a cast iron projectile.

(3) Items under Department 54.

Full Code: 54-Б-534

Shortened: Б-534

54, the supplying agency: Department 54.

Б, the type of item: propellant in a bag, for insertion into the cartridge case.

534, the model: for the 152mm Howitzer, Model 1909/30 - or its ballistic equivalent.

Next time: Identification Code Symbols, Markings