SA04 - Cartridges and Projectiles Flashcards
Non-Metallic Materials - REMEMBER THIS QUESTION
4 types of natural fibres
- CELLULOSE
- SILK
- WOOL
- RUBBER
Non-Metallic Materials - REMEMBER THIS QUESTION
Two main types of plastics
- Thermoplastic
- Thermosetting plastic
(3rd one is Engineering plastics mentioned separately)
Non-Metallic Materials
What is thermoplastic?
Soften on heating and reharden on cooling, allowing them to be re-shaped.
Non-Metallic Materials
What is thermosetting plastic?
Plastics that are acid insoluble and incapable of being softened by heat.
Non-Metallic Materials
What is used for non-permanent seals?
Luting
Corrosion and Season Cracking - REMEMBER THIS QUESTION
Types of defects in metals?
- Mechanical - Cracking due to stress
- Chemical - Corrosion due to impurities
Corrosion and Season Cracking
What is annealing?
It is the relief of work stress which is performed at the neck of the cartridge. Annealing makes larger crystals at the neck making it softer. The base has smaller crystals that are harder.
Corrosion and Season Cracking
Definition of corrosion
The conversion of metal to a non-metallic state.
Corrosion and Season Cracking - REMEMBER THIS QUESTION
Types of corrosion
- Rust (Ferrous Oxide) - Projectiles
- Aluminium Oxidation - Tail fin assemblies of (mortar)
- Mazak contamination (Magnesium, Aluminium, ZInc, Copper) (Fuze bodies)
- Cupric Azide (detonators and fuzes)
- Zinc exudation
Corrosion and Season Cracking
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
When are stresses most likely to be formed in metal & what can aggravate them?
The stresses may be formed in the metal during manufacture and which may be further aggravated by the environmental changes
HE Shell Filling Techniques
Requirements of HE Filling
The filling of the projectile is directly related to the cavity available
* Charge to weight ratio (CWR)
* Modern 20 to 30%
HE Shell Filling Techniques - REMEMBER THIS QUESTION
Types of filling techniques
- Casting
- Pressing
- Extruding
- Pre-forming/ cocooning
HE Shell Filling Techniques
Disadvantages of casting using hot melt process
- Shrinkage
- Cracking
- Dusting
HE Shell Filling Techniques
3 methods of casting explsoive fillings
- Straight pour
- Creamed
- Liquid and biscuit
Trace and Trace igniters
Purpose of tracers
- Emit light
- Maybe used as self destruct
Trace and Trace igniters
Purpose of Dark ignition
- Prevent the firer being dazzled by the brilliant flames emitted, and
- Reduce the possibility of the position of the gun being pin pointed by enemy observation from a flank.
Trace and Trace igniters
Principle requirements of tracer compositions
- Luminosity
- Strength
- Consistency of performance
- Ease of Ignition
Trace and Trace igniters
Means of igniting a tracer
- Direct Ignition - A cap sets back onto an anvil to initiate the igniter composition.
- Propellant Ignition - Ignited by hot propellant gases on firing.
Trace and Trace igniters - REMEMBER THIS QUESTION
Classification of Tracers
- Tracer Projectile
- Tracer and Igniter Projectile
- Integral Tracer
Trace and Trace igniters
3 Methods of securing tracer to projectile
- Threaded externally to screw into base
- Threaded internally for attachment to a screw treaded spigot
- Separate screws passing trough the tracer body
Trace and Trace igniters - REMEMBER THIS QUESTION
3 methods of sealing tracer
- Brass or Celluloid discs or cups
- NG and Carbamite
- Bakelite discs
Primers, Igniters and Tubes
What are Primers, Igniters and Tubes used for?
Employed for ignition of the propellant charge in QF, RCL and BL equipment.
Primers, Igniters and Tubes - REMEMBER THIS QUESTION
Types of Primers
- Percussion
- Electric
- Bridge wire
- Conducting cap
Primers, Igniters and Tubes
Design features of primers
- 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 - REMEMBER THIS QUESTION
Components of Percussion Primer
- Body
- Cap
- Anvil
- Plug
- Magazine
Primers, Igniters and Tubes - REMEMBER THIS QUESTION
Types of obturating system
- Cap holder
- Ball in cone seating
- Cone in cone seating
- Firing plug battery cup (sleeve)
Primers, Igniters and Tubes - REMEMBER THIS QUESTION
Components of Bridge wire primer
- Base
- Contact piece
- Bridge
- Magazine
Primers, Igniters and Tubes - REMEMBER THIS QUESTION
Components of Conducting cap primer
- Base
- Pole unit
- Cap
- Magazine
Driving and Rotating bands - REMEBER THIS QUESTION
Why are driving bands required?
or
What is the function of driving bands?
- To centre projectile in bore and impart spin.
- To prevent the forward escape of propellant gases.
- To assist in prevention of slipback of the projectile when loaded at high elevations.
Driving and Rotating bands - REMEBER THIS QUESTION
Requirements of a driving band
- No excessive pressure on the shell or barrel.
- Cater for change in bore diameter (wear).
- Remain firmly attached to the projectile.
- Must not alter the ballistic shape of the projectile (engraved state).
- Cause no excessive friction or bore wear.
- Simple to make and fit.
Driving and Rotating bands
Requirements of material used in driving bands
- The metal used must be soft, to give the least wear possible in the gun.
- Must not be so soft as to strip under the rotational and engraving process in the bore.
- Copper has been found to be the best.
Driving and Rotating bands
Methods of attachment of driving bands
- Split ring
- Solid ring
Driving and Rotating bands
Explain the split ring driving band attachment
A strip is cut to the required length, formed into a ring (ends butted) and pressed onto the shell by a multi-ram press.
Driving and Rotating bands
Explain the solid ring driving band attachment
A ring of correct width is cut from a length of seamless copper tube, slipped over the shell and pressed in the same method as for the split ring method.
Driving and Rotating bands
What are the methods of preventing twisting?
- Wavy Rib
- Knurling
Driving and Rotating bands
What are slipping rings used for?
Slipping rings are designed to ensure that the spin imparted by the weapons barrel does not reach a rate that would influence the fin stabilisation of a
projectile or would reduce the effectiveness of a hollow charge
Driving and Rotating bands - REMEMBER THIS QUESTION
Types of driving bands
Remember MPDOG
- Modern band
- Probert
- Double band
- Orthodox band
- Gas check type
Driving and Rotating bands
Materials used to make slip rings
- Plastic (nylon)
- Vulcanised rubber
- Polycarbonate (makrolon)
Metals and Alloys
Properties of metal
- Lustre
- Colour
- Density
- Hardness
- Conductivity
- Melting point
- Coefficient of expansion
- Hot Working
Metals and Alloys - REMEMBER THIS QUESTION
Where is copper used in ammunition?
- Driving Bands
- Detonators
- Shaped charge liners
- Cartridge Cases
- SAA jackets (gilding Metal)
Metals and Alloys
What is season cracking?
Brass is susceptible to stress corrosion cracking. The problem is sometimes known as season cracking.
Metals and Alloys - REMEMBER THIS QUESTION
Percentage of brass in catridge case brass
70% Copper, 30% Zinc
Metals and Alloys
Percentage of brass in admirality brass
69% Copper, 30% Zinc, 1% Tin
Metals and Alloys
Defnition of creep
A permanent change in the physical dimnensions of a metal caused by the application of a continuous stress
Projectile Definitions
Definition of 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 Definitions
Definition of 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.
Projectile Definitions
Definition of component
An item which is an integral part of a system, sub system or equipment.
Projectile Definitions
3 designs (types) of projectiles
- Shot
- Shell
- Carrier
Projectile Definitions
Types of bases on a projectile
- Boat tailed
- Cylindrical base
- Cylindrical base carrier shell
Projectile Definitions - REMEMBER THIS QUESTION
Different parts of the projectile
Page 6 of the projectile deifintion lesson pdf doc
- Lip
- Fuze Hole
- Ogive
- Shoulder
- Band
- Bourrelet
- Wall
- Base
- Driving Band
- Head
- Body
- Governing section
Projectile Definitions - REMEMBER THIS QUESTION
Classification (types) of projectiles
- Operational
- Weapon functioning/ inspection
- Training
Projectile Definitions
Types of operational projectiles
- Shot (KE)
- Shell
- Mortar
- Grenade
- Bullet
Projectile Definitions
Types of Weapon training/ inspection projectiles
- Bulleted Blank (SAA)
- Paper shot
- Proof
- Gun functioning
Projectile Definitions
Types of Training projectiles
- Practice
- Drill/ dummy
- Instructional
- Break-up
- Sub-cal
Projectile Definitions
Types of KE projectiles
- AP - Armour Piercing
- APC - Armour Piercing Capped
- APCBC - Armour Piercing Capped Ballistic Capped
- APDS - Armour Piercing Discarding Sabot
- SAP - Semi Armour Piercing
- APFSDS - Armour Piercing Fin Stabilised Discarding Sabot
Driving bands
requirements of a slip ring?
- Should breakup on leaving the barrel
- Should breakup into particles small enough so as not to harm friendly troops
- Chances of any fragments remaining in the barrel should be minimal
- The ring should still engage the rifling and not soften under bore temperature
Corrosion and Season cracking
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
Cart case design
Types of charge systems
- Cartridge case,
- Cloth bag
- Combustible cartridge case
Cart case design
What are the components of the propelling charges?
- Charge container
- Propellant
- Inititator
Cartridge systems - REMEMBER THIS QUESTION
Types of cartridge systems
- Breech Loading (BL) - Opens like an oven door
- Quick Firing (QF) - breech is closed by simple sliding motion
Cartridge systems - REMEMBER THIS QUESTION
What can BL guns be loaded with?
- Bagged charge system
- Modular Charge System (MACS)
Cartridge systems - REMEMBER THIS QUESTION
Components of BL systems
- Tubes/ Primers
- Bagged Charge
- Projectile
Cartridge systems - REMEMBER THIS QUESTION
Advantages of BL system
- Less stowage problems/ reduced length
- No cart case
Cartridge systems - REMEMBER THIS QUESTION
Disadvantages of BL system
- Slow loading process (3 components = slow)
- Slow rate of fire
Cartridge systems - REMEMBER THIS QUESTION
Types of QF CART system and define the main difference between them.
(worth 6 marks)
- QF Separate – PROJ loaded then Cart Case charge adjusted loaded afterwards
- QF Semi-fixed – PROJ and Cart Case charge adjusted, mated and then loaded
- QF Fixed – PROJ fixed to Cart Case loaded together
Cartridge systems - REMEMBER THIS QUESTION
How is rearward obturation acheived in QF and BL system?
- BL – rearward obturation is achieved by the gun.
- QF – rearward obturation provided by cartridge case.
Cartridge systems - REMEMBER THIS QUESTION
Components of QF system
- Cart case with primer
- Propelling charge
- Projectile
Cartridge systems - REMEMBER THIS QUESTION
Requirements of cart case
- Protection of contents
- Provide efficient obturation
- Easy loading and extraction
- Able to house primer
Cartridge systems
Requirements for charge bags
- Non-smoulder
- Non-stretch
- Non-wear
- Be insect, vermin and rot proof
Cartridge systems
Characteristics of material used in charge bags
- Protect and contain the contents
- Be totally consumable
- Allow the flash from ignition to pass easily through.
Cartridge systems
What are the advantages of QF Separate /Semi-fixed over QF Fixed?
- Adjustable charge
- Can replace damaged Cart Case
- Less stowage problems due to reduced length
RCL Cartridges and propellants
Principles of RCL
If two equal weights can be fired in opposite directions at equal velocity the weapon will be recoilless
RCL Cartridges and propellants
What are the types of RCL systems?
- Solid Cart Case with blow out Rear Disc
- Perforated cart case system
RCL Cartridges and propellants - REMEMBER THIS QUESTION
Advantages of RCL system
- No Recoil
- Low Weight
- Man Portable
- Mounted on Light Vehicles
RCL Cartridges and propellants - REMEMBER THIS QUESTION
Disadvantages of RCL Systems
- Flash/ Dust signature (BBDA)
- Low Velocity
- Large Propelling Charge
RCL Cartridges and propellants - REMEMBER THIS QUESTION
Explain the method of operation of the Solid cart case with blow out disc.
Propellant charge initiated, pressure builds up, blow out disc ruptures, the projectile is propelled forward and the propellant gases escape through the rear breech hole and out through the venturi.
RCL Cartridges and propellants
Explain the method of operation of the Perforated Cart Case
- On firing – Prop charge initiated
- Sheath ruptures allowing prop gases to escape through holes in cart case, into annular space, out through venturi
- Pre-rifled projectiles are used to alleviate pressure build up
Propellants charges and trends
Different types of propelling charges
- Fixed
- Semi-fixed
- Separate
Propellants charges and trends
Factors affect the choice of fixed ammunition
- Fixed charge weight (direct fire)
- High rate of fire / automatic loading
- All up weight and size of round should not make handling difficult
- Problem in obtaining a satisfactory case shell joint with a heavy projectile
- Required rate of fire of the system
- Extraction and ejection problems
- Disposal of fired cart cases
Propellants charges and trends
What is separate ammunition?
Projectile and charge are packaged separately and only joined in the chamber of the gun. E.g. 155MM Howitzer ammunition
Propellants charges and trends
What is the difference between a Combustible and Consumable cart case?
- Consumable. Material that is used up during the process of the combustion of the propellant. It is an inert material and does not contribute to the explosive process.
- Combustible. Material that is capable of burning and contains ingredients that contribute significantly to the production of propellant gasses.
Propellants charges and trends
Considerations for semi-fixed and separate ammunition system
- Charge can be adjusted so this type of system is used in most indirect fire weapons
- Ammunition is easily handled
- Stowage problems in AFVs may be eased
Propellants charges and trends - REMEMBER THIS QUESTION
Four types of bagged charges
- Equal
- Unequal
- Stem and Ring
- Stem and Segment
Propellants charges and trends
Design considerations for charged bags
- Be non-smolder
- Be non-stretch
- Be non-wear
- Be entirely consumed on firing.
- Leave no smouldering particles or residue.
- Be insect / vermin / rot proof
- Be permeable to the flash from the tube
Propellants charges and trends
What materials are used to make charge bags?
- Silk (Early days)
- Terylene/ cotton material
Propellants charges and trends
What is De-Coppering?
The process of cleaning the bore of the weapon of copper deposits left by the driving band.
Propellants charges and trends
Types of charge
- Normal - Does not provide maximum ballistic performance
- Super - Maximum permissible ballistic performance
- Reduced - Provides lower pressures and lower velocity (Used for training).
- Fractional - For large BL charges, divided for ease of handling
- Incremental - For the variation of ballistic performance in QF howitzer and guns
- Blank Charge - Charge of GP or prop of sufficient size to give a loud report. For salutes and training.
- De-coppering charge - Tin or Lead foil added to a propellant charge for de-coppering purposes.
Propellants charges and trends - REMEMBER THIS QUESTION
Types of cartridge cases
- Combustible
- Consumable
Propellants charges and trends
Advantages of Cart cases
- No spent cart case to be collected or extracted
- Less fumes
- Ammunition weight is less.
- Easier to adjust charge.
- Reduced barrel wear.
- No cluttering at the gun site.
Propellants charges and trends
Disadvantages of cart cases
- Lack of strength
- Residue left
- Additional components to load.
- Chance for a “cook off”.
- Ingress of moisture.
- New propellant had to be developed which was insensitive to sparks & static High Ignition Temp Propellant (HITP)
Propellants charges and trends
Composition of cart cases
Mixture of NC fibres and inert cellulose with additives for stabilisation and strength.
Propellants charges and trends
Types of liquid propellants for guns
- Regenerative system
- Travelling Charge Injection system
Propellants charges and trends
What are the two design principles of Bagged
Charges?
- The lowest charge must be stable so it does not lose its shape when loaded alone and cause a misfire or delay in complete ignition
- The igniter, which is always fitted over the lowest charge is made of the largest possible diameter.
ERP, ICM And TGM
Max range of 155mm
30KM
ERP, ICM And TGM - REMEMBER THIS QUESTION
How does Rocket Assissted Projectile work?
- Rocket cap removed prior to loading
- On firing propellant gases ignite delay composition – 7 sec delay
- Delay ignites rocket igniter and main rocket motor propellant
- Boost phase – 2 secs, Sustain – 7 secs
- Propellant gases released through venturi
ERP, ICM And TGM - REMEMBER THIS QUESTION
How does base bleed work?
- Non-ballistic solution achieved by generating gases and filling the vacuum at the base of the shell during flight
- Solid grain propellant ignited by propellant on firing
- Burns slowly to fill vacuum which increases air pressure
- Does not propel round, it eliminates drag
- Base drag reduced by 70%, increase range by 10% - 20%
ERP, ICM And TGM
What is a Rocket Assissted Projectile?
Rocket motor inserted in the base of the projectile which is activated after the shot ejection.
Cartridge Systems
Explain QF Semi-Fixed cartridge
- PROJ and Cart case packed together.
- Mated together and Loaded as one unit.
- Projectile rammed by Cart case.
- Adjustable charge.
Cart case Design - REMEMBER THIS QUESTION
Reasons for using brass in cart cases
- Performs well in most equipment.
- Metallurgy and techniques are well know.
- Does not corrode to give hard abrasive particles.
Cart case design
3 methods used to fix projectiles to cart case
- Coning
- Canneluring
- Coning & Canneluring
Cart case design
What is coning?
The mouth of the cartridge case is turned into a groove or cannelure situated around the base of the projectile, just below the driving band.
Cart case design
What is canneluring?
Canneluring requires the pressing of the mouth of the case into a groove or cannelure, near the base of the projectile. Canneluring can be spaced or continuous.
Cart case design
Methods of filling cart cases
- Loaded directly or into charge bag or bags
- Charge bags used in multi – charge systems
- Charge bag may be used where charge weight is small in relation to the volume of the case
Cart case design
Advantage of CCC
Everything loaded into the chamber plays some part in ballistics
Cart case design
Disadvantage of charge bags
- Lower charges of a multi charge system that a disproportionate amount of cloth is loaded
- At low pressures there is a danger of incomplete combustion
Cart case design
What is CCC made of?
Nitrocellulose, Kraft paper and resins, resembles hard cardboard
HE Shell Design
Factors that affect shell design
- Target effect
- Ballistic performance
- Strength to withstand firing stresses
- Economy in manufacture
- User requirements
- Safe handling ,transportation and storage
HE Shell Design
Effects required at the target
- Physical - Casualties to person, Damage to materials
- Psychological - Neutralisation, Demoralisation
HE Shell Design
5 design factors to obtain efficiency of fragmentation
- Material of the shell – composite steel
- The capacity – increased due to thin walls
- Main fill – RDX/TNT/HMX/HNS
- Method of exploding
- Fuze and fragment zones
HE Shell Design
optimum stabilisation for
- Spin stabilisation – up to 7 calibres
- Large calibre shells – 5 to 6 calibres
HE Shell Design
Forces acting on a projectile
- Gas pressure - 800m/s
- Acceleration -5800g
- Setback
- Heat
- Centrifugal
- Driving band pressures
- Side slap
- Hoop stress/shear stress
- Drag
HE Shell Design
Position of the driving band
- Far to rear as possible
- Forward of the streamlining
- Fixed ammunition forward
HE Shell Design - REMEMBER THIS QUESTION
In service environment, the ammunition must be able
- To withstand rough usage;
- To withstand storage in varied climates at high and low temperatures; and
- To need as little in-service maintenance as possible.
HE Shell Design
How is nose and base drag reduced?
- Nose drag is reduced by head shape (Ogive)
- Base drag is reduced by base shape (Boat tail)
HE Shell Design - REMEMBER THIS QUESTION
3 ways to manufacture HE Shells
- Cast
- Forged
- Extruded
Carrier Projectiles - REMEMBER THIS QUESTION
Definition of Carrier Projectiles
Carrier projectiles are those in which the projectile body is used as a vehicle for conveying a payload to the target area.
Carrier Projectiles
Types of carrier projectiles
- Smoke
- Illumination
- Conventional Anti-personnel
- Sub Projectiles
- Flare
- Incendiary
- Radar Echo
- Chemical
- Propaganda
Carrier Projectiles
Composition of coloured smoke
A typical coloured smoke mixture consists of a fuel, an oxidant and a dyestuff in the approximate ratios of 1 :1 :2.
Carrier Projectiles
Types of conventional anti-personnel carriers
- Shrapnel
- Canister shot
- Flechettes
Carrier Projectiles
What is the main constituent of incendiary compositions?
Magnesium
Carrier Projectiles
Methods of operation of carrier projectiles
- Bursting
- Base ejection
- Nose ejection
- Base Emission
Exploder and Supplementary Charges
Definition of Exploder
A charge in the form of a pressed pellet or filled container of secondary explosive designed to amplify the detonation wave produced by a fuze detonator or magazine to ensure efficient detonation of the main charge.
Exploder and Supplementary Charges
Definition of exploder system
The components used for transmitting the impulse from the fuze or booster to the HE filling.
Exploder and Supplementary Charges - REMEMBER THIS QUESTION
Supplementary charges contained in metal provide 3 main benefits. List them.
- Ease of removal.
- Setback movement eliminated.
- No explosive migration.
Exploder and Supplementary Charges
Definition of Supplementary charge
A cylindrical aluminium container, (filled with either TNT or Comp B) which is used to fill the cavity below the fuse in deep cavity projectiles. It is removed when some proximity fuzes are fitted to the projectile
