Summative 4 - Cartridges and Projectiles Flashcards
Non-Metallic materials: Natural fiber
List
List the 4 main natural fibres used in EO
CELLULOSE
SILK
WOOL
RUBBER
Non-Metallic materials: Cellulose
List/Definition
Define cellulose,
What are the two common forms of cellulose and what are they used in?
Definition :
- Polymeric substance found in vegetable matter.
Classed as harmless with explosives unless mixed.
Types and uses:
- Cotton.
Used for cotton charge bags. - Wood / paper.
Used for cardboard in pyrotechnics.
Cardboard used extensively in pyrotechnics.
Non-Metallic materials: Silk
List
What are the 6 main properties/considerations of silk
Protein structure.
Stable.
Expensive.
Used to tie bundles of cordite to form propellant charges.
Make bags for loose prop charges.
No residue left as with cotton.
Non-Metallic materials: Wool
List
What are the 4 main properties/considerations of wool
Protein based.
Shallon (a type or blend of wool) was used as gunpowder igniter.
Today used for felt pads.
Disadvantage:
Very high water absorption rate.
Non-Metallic materials: Rubber and synthetics rubbers
List
What are the 3 main properties/considerations of Rubbers
Natural rubbers are avoided due to deterioration in extreme temperatures.
Silicone rubbers are reasonably resistant to climatic extremes.
Rubber composition bitumen is widely used in Squash Head.
Non-Metallic materials: Plastics
List
What are the 3 main properties/considerations of Plastics
- Includes resin & plastics.
- Finished product will contain substances other than the basic polymer.
- Two main types of plastic:
Thermoplastic.
Thermosetting plastic.
Non-Metallic materials: Plastics
Definition / List
Define a Thermoplastic (2 points), and give an example.
- Soften on heating and re-harden on cooling, allowing them to be re-shaped.
- Number of times for re-shaping is restricted due to the plastic degrading.
Cordite is a thermoplastic in which the properties of the base polymer NC, have been modified by plasticisation.
Non-Metallic materials: Plastics
Definition / list
Define a thermosetting plastic (3 points)
Plastics that are acid insoluble and incapable of being softened by heat.
Used in casting of non-metallic land mines and glass fibre rocket motor cases.
Higher physical properties than steel but lighter.
Non-Metallic materials: Plastics
List
What are two advantages of engineered or improved plastics
Higher tolerance than normal plastics.
Most are fibrous reinforced which improves their performance.
Non-Metallic materials: Paints and varnishes
List
List the seven arbitrary and unrelated points on Paints and Varnishes.
- Must not react with explosives.
- Copal varnish.
To protect inside of shells against ammonium nitrate. - Shellac.
To protect brass cart cases against nitrous oxide (produced by cordite) - Varnishes based on bitumen.
- Developed for coating iron and steel surfaces of HE stores.
- Cementing in cardboard closure caps.
- Slow drying and all excess must be removed:
Solvent / air diesel effect.
Can be disastrous if the solvent is flammable.
Non-Metallic materials: Adhesives, Cements, and Luting
List
List the 4 common properties or requirements of adhesives, cements, or Luting
- Must not react with explosives.
- Must have strength and be water resistant.
- Permanent.
Adhesives or cement. - Temporary.
Luting (soft setting compositions).
HE shell filling techniques: Methods of filling
List
List the 4 main filling techniques and their sub-components
- Casting;
Straight pour
Creamed
Liquid and biscuit - Pressing;
Pressing
Incrementally into case
Pre pressed charges
HE shell filling techniques: Methods of filling
List
List the 4 main filling techniques and their sub-components
- Casting;
Straight pour
Creamed
Liquid and biscuit - Pressing;
Pressing
Incrementally into case
Pre pressed charges - Extruding
Direct extrusion into case - Pre forming / cocooning
Land mines
HE shell filling techniques: Casting and extruding
List
List the 5 consideration of casting and extruding
CCSSD
Cooling Range
Shrinkage
Structure
Cooling rate
Dust migration
HE shell filling techniques: Casting and extruding
List
List the 3 main disadvantages of hot/melt fillings
Shrinkage
Cracking
Dusting
HE shell filling techniques: Casting and extruding
List
List the ways of overcoming the following disadvantages/drawbacks of hot/melt fillings:
Shrinkage
Dusting
Cracking
Shrinkage
- Encapsulation
- pre-cast encapsulation
Dusting
- Terylene
- Glass fibre
- add lubricant
Cracking
- additives
- nucleating
- strenghtening
- plasticising
- seeding
- in conjunction with nucleating
HE shell filling techniques: Pressing
List
In addition to the separation of increments of pressed explosive, what 5 other disadvantages arise with pressing?
Tooling cost
Size limitations
Density gradients
Projectile design
Accuracy
HE shell filling techniques: Shell linings
List
What are the 3 considerations of shell linings?
The metal of which they’re made,
The protection of the fill,
and the ensuring the adhesion of internal coatings
Corrosion and Season Cracking:
List
List literally every element that alloy with iron/steel
Aluminium Bismuth Boron Chromium Copper Lead Manganese Molybdenum Nickel Silicon Sulphur Titanium Tungsten Vanadium
Corrosion and Season Cracking: Metals
List
List some more metals and what they can alloy with/are alloys of.
- Steel
Iron with Carbon as the major alloying element - Brass
Is Copper with the major alloying element being Zinc - Aluminium
Any of the following elements may be the major alloying
element: Copper, Magnesium, Magnesium & Silicon or Zinc - Mazak
Magnesium + Aluminium + Zinc and (K)opper
Primarily Zinc with the major alloying element being
Aluminium.
Corrosion and Season Cracking: Defects
List
List the 2 major types of defects found on metals/metal alloys
- Mechanical
Cracking due to stress - Chemical
Corrosion due to impurities
Corrosion and Season Cracking: Annealing
List
What is annealing?
Why i it useful
Heating of a metal in order to relieve work stresses.
It creates larger metal crystals, which make the metal softer.
Can be used to prevent mechanical defects, eg around the neck of a cartridge neck once formed.
Corrosion and Season Cracking: Defects
Definition
Define season cracking
Stressed areas of metal cracking due to the affect
of ammonia forming Cuprammonium during storage
in either hot or cold temperatures
Corrosion and Season Cracking: Defects - corrosion
List
List the definition, cause, and factors affecting rate of corrosion
- Definition:
The conversion of metal to a non metallic state. - Cause:
Chemical reaction - Rate or Corrosion:
Ambient air temperature
Humidity
Chemical impurities in the packaging material
Corrosion and Season Cracking: Defects - corrosion
List
List 5 types of corrosion
- Rust - (iron Oxide)
- Aluminium oxidation
- Cupric Azide contamination (corrosion of Lead Azide in moisture, and subsequent acid reaction with CU case, creating Copper Azide)
- Zinc Exudation / Free Copper (copper dissolves out of brass, creating areas of zinc deficient copper, and causing pores)
- MAZAK contamination (MAZAK is used in fuze bodies, breakdown will make unreliable, inoperable and dangerous fuzes.)
Corrosion and Season Cracking: Inspection, Sentencing and Repair
List
What must be done after cleaning a cartridge?
Wiped clean with Acetone or Alcohol
Wiped with a clean dry cloth
Cleaned steel repainted
Corrosion and Season Cracking: Inspection, Sentencing and Repair
What makes a cartridge unserviceable?
pitting or flaking is present
Corrosion and Season Cracking: Inspection, Sentencing and Repair
How do you remove corrosion from cart
cases?
Use of white spirit or light grade emery paper
If the corrosion is severe sentence ammo according
to inspection pam
Primers, Igniters and Tubes: Primers - Percussion
Definition
Explain how Percussion primers function
Functioned by a mechanical blow of a striker onto the percussion cap assembled in the base of the Primer.
Small flash given by the percussion cap is picked up an amplified by the gunpowder charge in the magazine portion of the primer.
Primers, Igniters and Tubes: Primers - electric types
List
List the two broad types of electric primers and define each
Bridge wire type
- Initiation is achieved by passing an Electric Current through an insulated copper wire & bridge, firing a priming composition which surrounds the bridge.
Conducting cap
- Conducting cap composition which is fired by passing an electric current through the cap filling.
ADV:
Possibility of Misfires as a result of a broken bridge wire is eliminated & assembly is simplified.
Primers, Igniters and Tubes: Primers general
List
List the 5 design features and requirements of a primer
Produce Sufficient Flash to ignite the propellant.
Pass the flash evenly over the propellant.
Be self obturating, externally and internally.
Protect the Gunpowder & propellant from moisture.
Flush fitting Screwed / Press fit.
Primers, Igniters and Tubes: Primers - Percussion
List / definition
List and define the 5 components that make up the construction of of a percussion primer
Body
- Contains all components.
Cap
- Holds initiating composition.
Anvil
- Shaped metal component is located above the Cap.
- Provides the resistance to the crushing action of the Striker which cause the composition to ignite.
Has flash holes for the passage of the Flash.
Contains the seating for internal obturating device.
Plug
- Provides the fire channels through which the flash passes to the magazine.
- Retains cone/ball of the sealing device.
Magazine
- May be recess in body or be a separate cylinder
Primers, Igniters and Tubes: Primers - Perscussion
Definition
Define Internal and an external obturating system
External
-Achieved by the expansion of the wall of the primer body against that of the Cart Case.
Internal
- Employing some form of stopper in the body, which on the ignition of the Magazine effectively plugs any attempt by the gases to escape rearwards.
- Ball Seal.
- Cone Seal.
Primers, Igniters and Tubes: Primers - Percussion
List
List the sequence of events in the percussion primer when fired.
Striker/Firing Pin strikes the Cap.
Crushes the initiating composition against the anvil.
Flash passes through the Firing Channels in the anvil & plug to the Gunpowder in the Magazine.
Magazine Fires, Primer Body Expands against the Cart Case, thereby ensuring external obturation.
Ball or Cone is forced back into the fire channels internal obturation.
Primers, Igniters and Tubes: primers - bridge wire
List / define
List and define the 4 parts of a Bridge wire primer
Base
- Screw threaded externally to engage in the Base of the Cart Case.
- Interior is bored & screwed threaded to take an Ebonite Cup, contains the contact piece & bridge wire.
- Recess is formed in body to hold small QTY guncotton dust around the bridge & gunpowder pellet above it.
- Forward end of body is screw threaded to accept the Magazine.
Contact Piece:
- The initial Contact which is housed in the Ebonite Cup.
Bridge:
- Consists of a short length of iridio platinum wire, both ends of which are secured to the Bridge plug.
- One end is attached to acopper wire runningdown the insulated centre of the body to a contact piece.
- The other to an earthed pole
Magazine:
- Separate cylindrical brass container.
- Holds GP.
Primers, Igniters and Tubes: Primers - bridge wire
List
List the sequence of events of a bridge wire primer when fired
Round loaded into gun, breech closed, needle moves forward on to the Primer Contact.
On Firing ,current flows through the needle contact
piece & insulated copper wire to the primer, cart case & gun to complete the circuit.
Bridge wire heats thus igniting the gunpowder dust gunpowder pellet magazine.
Primers, Igniters and Tubes: Primers - Bridge wire
List
List the 2 obturation forms for Bridge wire primers
External
As for other primers.
Internal
Copper bridge plug, setting back into the cone
seating in the base.
Primers, Igniters and Tubes: Primers - Conducting cap
List / Defitnition
List the 4 components of construction of a conducting cap and define them.
Base
Pole unit
Cap
Magazine
Base:
- Screw threaded externally to engage in the base of the cart case.
- Remainder of Body screw threaded on a reduced diameter for attachment of the magazine.
- Interior is bored & screwed threaded at the rear to house a Plastic Insulating Cup, containing a Brass contact
- piece & Pole Unit.
- Forward portion of Body recessed & screw threaded to accommodate a conducting Cap & a Closing Plug.
Conducting Cap:
- Brass Pole, tapered towards the rear which has a plastic insulating sleeve moulded to it.
- Drilled at the forward end to house a small Phosphor Bronze Spring , which ensure continuity of the Circuit between the conducting cap pole.
Cap:
Incorporates a brass pole piece which is insulated and surrounded by the Conducting Cap Composition.
Magazine:
- Separate cylindrical brass container. Holds GP.
Primers, Igniters and Tubes: primers - Conducting cap
List / define
List and define the 2 types obturation for conducting cap primers
- External
As for other primers. - Internal
Tapered pole unit setting back into a corresponding
recess in the base.
Primers, Igniters and Tubes: primers conducting cap
List
List the sequence of events of a conducting cap primer when fired
Round loaded into gun, breech closed, electric needle moves forward on to the Primer Contact.
On Firing , current flows through the needle contact piece & pole unit to the pole piece of the cap.
The filling in the cap is a conductor due to the inclusion of graphite, permitting current to pass through this to the brass distance piece & outer case of the cap, and back through the body of the base, Cart Case, gun to complete the circuit.
Heating occurs, composition ignites to produce a flash magazine.
Primers, Igniters and Tubes: Tubes
List/define
Where is a tube used and what dos it do
Used with separate loading bagged propelling charges.
Produce a flash sufficient to ignite the igniter.
Primers, Igniters and Tubes: Tubes
Definition
Explain how the obturation works with a tube
Tapered body of the tube is closed.
On firing, the thin wall of the tube expands against wall of the vent.
Head of tube is supported during firing by the striker lock, which prevents any movement of the tube.
Primers, Igniters and Tubes: Igniters
List
List the three types of igniters
Two consisting of supplementary charges of gun powder used to augment the flash from primer or tube.
Third being used in solid rocket propellant motors to ignite propellant.
Primers, Igniters and Tubes: Igniters
List
List the two types supplementary types of igniters
- BL Charge Igniters;
Attached to end of BL charges and whose function is to ensure the charge is ignited. - Igniters, cartridges;
Supplementary charge of gunpowder used to amplify flash produced by the primer.
Ignition of the propellant at centre of charge.
Tracer and tracer ignition: Trace general
List
What is the purpose of tracers?
Emit light.
May be used as a Self destruct.
Tracer and tracer ignition: dark ignition
List
What are the 2 purposes of dark ignition
Prevent the firer being dazzled by the brilliant flames emitted.
Reduce the possibility of the position of the gun being pin pointed by enemy observation from a
flank.
Tracer and tracer ignition: Tracer general
List
List the 4 requirements of tracer composition
Luminosity
Strength
Consistency of Performance
Ease of Ignition
Tracer and tracer ignition: Tracer general
List
What are the two means of ignition?
Direct ignition
- A cap sets back onto an anvil to initiate the igniter composition
propellant ignition
- Ignited by hot propellant gasses on firing
Tracer and tracer ignition:
List
What are the 3 classification of tracers
Tracer projectile
tracer and igniter projectile
integral tracer
Tracer and tracer ignition: Class - Tracer Projectile
List
A Tracer projectile is made of a steel or metal rod, with internal or external filling.
List how the fitting is
secured:
Sealed:
actioned
Method of Securing:
- Threaded externally to screw into base.
- Threaded internally for attachment to a screw treaded spigot.
- Separate screws passing trough the tracer body.
Method of Sealing:
- Brass or Celluloid discs or cups.
- Sealing methods vary considerably.
- Nitro Glycerine and Carbamite.
- Bakelite discs.
Action:
- Sealing arrangements are ruptured or consumed by propellant gases.
- Priming composition ignited.
- Ignites tracing composition.
Tracer and tracer ignition: Class - Tracer and igniter projectile
List
What are components and function of a Tracer and Igniter projectile
Steel or brass rod.
A separate component issued assembled with projectile.
Dual Function as a Self Destruct.
Tracer and tracer ignition: Class - Integral tracer
List
In what type shot is integral tracer used?
Only in solid shot, pressed into the shot and is integral to the ammunition
Metals and alloys: Metals
Definition
What is a metal?
Key points/words
Elemental - being a single element
crystalline structure when solid
characterised by ductility, conductivity, reflective etc
Metals and alloys: properties
Definition
Define hardness, malleability and ductility
This is perhaps the most important property of any
metal along with malleability and ductility. Hardness is the measure of a metals ability to resist deformation.
Malleability is the ability of a metal to be shaped
using forces without breaking the structure of the
metal.
Ductility is the ability of a metal to be drawn out in to
an elongated form again without affecting the
structure of the metal.
Metals and alloys: properties
Definition
define coefficient of expansion
This is the measurement of the amount a metal expands at a given temperature and when taken along with the elasticity of a metal
This particular property is the reason why brass is used to manufacture cartridges.
Metals and alloys: definitions
Definition
What is metallurgy?
Metallurgy is the exact science and
technology of the use of metals:
- The process of producing metals by extracting them from their base ores.
- Refining and purifying these metals.
- The study of the physical and chemical properties of these metals.
- The mechanical working of these metals.
Metals and alloys: definitions
Definition
What are 4 properties of copper?
What 5 things is copper used for? DDSSC
Properties:
- Metallic element that is ductile and malleable and one of the best conductors of heat and electricity.
- Copper can be found as either native copper or as part of other minerals.
- Exposed surface has a reddish orange tarnish.
Uses:
- Driving Bands
- Detonators
- Shaped charge liners
- Cartridge Cases
- SAA jackets (gilding Metal)
Metals and Alloys: definitions
List
What are the typical properties of brass
List and define the different alloys of and ratios of copper zinc alloys.
What two metals are in bronze?
Brass is harder and stronger than copper,, it is malleable and ductile, non-magnetic, and melts at 900-940 degrees
Cartridge Brass
- 70% Copper 30% Zinc
Gilding Metal
- 95% copper and 5% zinc
Admiralty Brass
- 69% copper, 30% zinc, and 1% tin which inhibits dezincification in many environments
Bronze is, generally, copper and tin
Metals and Alloys: Properties of metal
List
What two things can reduce the conductivity of a metal?
impurities, even in small amounts
work hardening
Metals and alloys: properties
Definition
What temperature do most metals melt below?
1100 degrees C
Metals and alloys:
Definition
What is a metalloid
a metal with metallic properties and non-metallic properties
Metals and alloys:
Definition
What is specific gravity?
Specific gravity is the ratio of the density (mass of a unit volume) of a substance to the density (mass of the same unit volume) of a reference substance.
The reference substance is nearly always water for liquids or air for gases.
Metals and alloys:
Definition
What is anodising?
Anodising is an electrolytic passivation process used to increase the thickness of the natural oxide layer on the surface of metal parts.
The process is called “anodizing” because the part to be treated forms the anode electrode of an electrical circuit.
Anodizing increases corrosion resistance and wear resistance, and provides better adhesion for paint primers and glues than does bare metal.
Forms an oxide over the surface which provides the corrosion resistance.
Metals and alloys: Iron
Definition
What are the properties of iron?
A heavy, ductile, malleable, magnetic element that occurs naturally in meteorites and most igneous rocks.
It is one of the most common elements on Earth.
Metals and alloys:
Definition
Define alloys
Alloys are metallic substances that contain more than one chemical element.
Usually they comprise a number of metallic elements.
Alloys are sub divided into ferrous alloys (those that contain iron) and non ferrous alloys (those that do not contain iron).
Metals and alloys: Steel
Definition
Define steel
Steel is an alloy of iron and carbon, can be up to 1.7% carbon
Metals and alloys: Steel
Definition
Define steel
Steel is an alloy of iron and carbon, can be up to 1.7% carbon
Metals and alloys:
Definition
Define sintering
Compressing metal particles into a coherent solid body. Carried out under heat but at a temperature below the melting point of a metal.
Metals and alloys:
Definition
Define creep
A permanent change in the physical dimensions of a metal caused by the application of a continuous stress.
Metals and alloys:
Definition
What is hot working
A process of working a metal into a different shape while hot.
A metal that has the ability to be hot worked, will retain its toughness when worked, and not become brittle.
Projectile definitions, terminology:
List / define
Define round, projectile, component
ROUND
A complete assembly of a projectile (with or without fuze), a propellant charge in a cartridge case, and the means of igniting the propellant charge.
PROJECTILE
An object capable of being propel led by a force, normally from a gun, and continuing in motion by virtue of its kinetic energy.
COMPONENT
An item which is an integral part of a system, sub sy stem or equipment.
Projectile definitions, terminology:
List
List the three basic types of projectile design
Shot
Shell
Carrier
Projectile definitions, terminology: Description
Definition
Define body
The empty body or shot, with driving band, before filling with the payload or tracer or other components.
Projectile definitions, terminology: Description
Definition
Define head
The complete portion of the projectile forward of the shoulder (US term).
Projectile definitions, terminology: Description
Definition
Define base
The part of the projectile rear of the driving
band, the types are Boat or cylindrical tail.
it has either a Base plates or Base cover.
Projectile definitions, terminology: Description
Definition
Define Bands
Sections of the shell wall may be accurately machined to a greater external diameter than the rest of the shell body. Is located immediately rear of the shoulder and forward of the Driving Band.
the front bad is often referred to as the bourrelet
Projectile definitions, terminology: Description
Definition
Define Driving band
The attachment to the outside of the projectile, usually to the rear. Primary function to provide obturation and impart spin to the projectile.
Projectile definitions, terminology: Description
Definition
Ogive
The shaped part of a normal projectile from the shoulder forward. It is the main radius of the head.
US usage: the entire head.
Projectile definitions, terminology: Description
Definition
Define shoulder, cavity, and wall
SHOULDER
The junction of the Head with the rest of the Body.
CAVITY
The space or spaces within the projectile, which may
accommodate the payload.
WALL
That part of the shell body that surrounds the cavity.
Projectile definitions, terminology: Description
Definition
Define governing section, fuze hole/well, and Lip
GOVERNING SECTION
That part of the projectile forward of the Driving Band at
which the stress on firing is maximum.
FUZE HOLE /WELL
The portion of the projectile head or base designed to hold
a fuze.
LIP
The junction of the fuze well liner and the projectile body.