SA4 Directed Study Flashcards
155 Diagram parts
Lip
Fuze hole
Ogive
Head
Shoulder
Body
Band
Bourrelet
Wall
Driving band
Base
Components that make up a breech loading system (M777)
Tube/Primers
Bagged charge
Projectile
Requirements of a cart case
Protect contents
Provide efficient obturation
Easy loading & extraction
Able to house the primer
Types of bagged charges
Equal
Unequal
Stem & Ring
Stem & Segment
Types of quickfire cart systems (Define/Example)
Separate - 155mm howitzer
Semi-fixed - 105mm howitzer
Fixed - 120mm tank
Requirements for driving band
No excessive pressure on shell or barrel
Cater for change in bore diameter
Remain attached to the projectile
Understand operation of solid cart case with blow out disc
Propellant charge initiated
Pressure builds up
Blow out disc ruptures, projectile propelled forward and the propellant gases escape rearward
Explain Base Bleed & Rocket assist projectiles
Base Bleed - Solid grain propellant ignited on firing, burns slowly to fill vacuum which increases air pressure to eliminate drag
Rocket Assist Projectiles - Rocket cap removed prior to loading, gases ignite delay composition which ignites rocket motor
What material makes up a brass cartridge
Copper 70%
Zinc 30%
How is rearward obturation achieved in the quick fire system
Cart Case
4 main components of a conducting cap primer
Base
Pole unit
Cap
Magazine
Reasons for using brass in a cart case
Performs well in equipment
Metallurgy well known
Does not corrode to give abrasive particles
3 Types of corrosion
Rust
Aluminium Oxidation
Cupric Azide
3 classifications of tracer
Tracer Projectile
Tracer & Igniter Projectile
Integral Trace
4 main HE filling techniques
Casting
Pressing
Extruding
Preforming/Cocooning
3 ways to manufacture a shell
Cast
Forged
Extruded
Define carrier projectiles
Projectile body used as a vehicle for conveying a payload to a target
Supplementary charges contained in metal provide three main benefits
Ease of removal
Setback movement eliminated
No explosive migration
What is de-coppering
The process of cleaning the bore from copper deposits left behind
What is the difference between combustible and consumable cart cases
Consumable - Material that is used up and does not contribute to the ballistic effect.
Combustible - Material that is capable of burning and contributes to the ballistic effect.
Different charge types (6-7)
Normal
Super
Reduced
Fractional
Incremental
Blank
De-coppering
Design principles of Propellant
Lowest charge must be stable to not lose shape, igniter sits over the lowest charge and made of the largest possible diameter.
What is IRON
A heavy, ductile, malleable and magnetic element. One of the most common elements on earth.
What is COPPER
A ductile, malleable and metallic element. One of the best conductors.
Means of Tracer ignition
Direct ignition
Propellant ignition
Requirements of Tracer compostion
Luminosity
Strength
Ease of ignition
Consistency of performance
Types of Natural Fibres
Cellulose
Silk
Wool
Rubber
What are the 2 main types of plastics with ammunition? What is the difference?
Thermo Plastic
Thermosetting Plastic
Thermo Plastic can be reheated and reshaped. Thermosetting Plastic cannot be softened by heat.
What is used for non-permanent seals?
Luting
Define corrosion?
Conversion of a metal to a non-metallic state
Requirements/Design Considerations for Chargebags?
Non Smoulder
Non Stretch
Non Wear
Be insect, vermin and rot proof
Be entirely consumed on firing
Be Permeable to the flash from the tube
What are the 2 different types of metal defects
Chemical
Mechanical
How are driving bands stuck on projos
Knurling
Wavey ribs
