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