LO8 - Theory of Design Flashcards
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Definition of SAA.
Small arms ammunition is normally defined as, “Ammunition for weapons such as pistols, rifles and machine guns below 20 mm in calibre”.
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In SAA, a complete round is normally made up of the following 4 main parts
- Cartridge case
- Ignition system
- Propellant charge
- Projectile
Explanation of different parts of SAA
Cartridge Case - Designed to hold the propellant charge, incorporate the ignition system, retain the projectile and provide obturation
Materials used in SAA
Generally made from ‘ cartridge brass ‘ although aluminium, cupro nickel or steel may be encountered
Cartridge Brass –70/30 copper/zinc alloy
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Soft mouth necessary for the following reasons:
- Expand as soon as pressure rises in chamber
- Establishes an early seal
- Prevents gas leakage
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Hard base necessary for the following reasons:
- Enable case to withstand internal pressure and rearward thrust from propellant gases
- Stresses applied by extractors
- Chambering/rechambering rounds
- Extraction of empty cases
Methods of securing bullets to cart case
- Press fit
- Canneluring
- Indenting
- Stabbing
- Coning
- Crimping
Types of ignition system in SAA
- Berdan
- Boxer
- Rim Fire
Propellants used in SAA?
- Single and double based propellants
- Double based are 15 – 20% more energetic but increase erosion
- Modern double base propellants contain less Nitro-Glycerine (NG) to reduce wear
- NATO 5.56mm contains Nobels Nitro-Neonite (90% NC, 8% NG), Carbamite which acts as a stabiliser and coolant and graphite, a surface cleaner and moderant
Design of projectiles is governed by its what?
- Target characteristics
- Effect required on the target
- Maximum effective range
- Ballistics
- Type of weapon
Colour coding of projectile tips
- Black – AP
- Silver – API
- Blue – Incendiary
- Yellow – Observing
- Red – Tracer
- Uncoloured - Ball
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Explain set up
- Forward obturation by base expansion of the projectile by propellant gases.
- Efficient if the projectile has no boat tail
Definition of grenade
A grenade is a small explosive store designed for projection by hand or from a personal weapon”. Occasionally a special discharger or launcher may be used.
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Design Categories of grenades
- Hand Thrown.
- Projected - Rifle launched/gun fired.
- Discharger- Weapon/vehicle launched.
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Different payloads in a grenade
- High Explosive Anti-Personnel.
Defensive
Offensive. - High Explosive Anti-Tank. (HEAT) and Dual Purpose.
- Smoke.
- Chemical or Irritant.
- Flash or Noise composition - (Stun).
- Incendiary.
- Practice.
- Illuminating.
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Typical components of a grenade
- Body
- Filling
- Fragmentation
- Fuze Cavity
- Fuze
What is an offensive grenade
- Offensive grenades rely solely on the effect of blast for their anti-personnel effect.
- To cause any physical damage to a man, a blast grenade must burst very close to him or at least in a confined space with him.
- Their usual effect is to stun or disorientate a man so that he is incapable of rational reaction for a short period of time.
what is a Defensive grenades
- These grenades are designed for use when the thrower is fully or partially protected in a defensive position.
- The large lethal area is achieved using fragments projected at high velocity.
What are screening and signaling smoke grenades?
- Screening Smoke grenade is designed to produce a dense curtain of smoke masking the removal or deployment of personnel in tactical and training situations.
The original screening grenade had a White Phosphorous (WP) fill with a HE disruptive fuze that burst the casing on initiation. - Signalling smoke grenades are used for a variety of signaling purposes and operate in the same manner as an igniferous initiated screening grenade.
What is an Chemical/ Irritant grenade anti-riot?
- Filled with lachrymatory or irritant compositions.
- The emission principle is rarely used now, since rioters tended to throw them back!
- Current designs utilise a rubber body containing a large number of primed CS pellets, that on initiation, create gas pressure bursting the body, and spreading the pellets.
What is Flash or noise - stun grenades?
- The police and special forces use stun or disorientation grenades as a non-lethal weapon.
- They incorporate pyrotechnic powders which produce high noise (in excess of 130 db) and flash values sufficient to disorientate anyone in the vicinity.
- Designed to produce no fragmentation.
- Stun and disorientate.
- Blinding flash load report and mild blast.
- Single or multiple functioning.
Incendiary grenade
- Used for numerous tasks, including;
as an IEDD Tool
as an initiator - Body colour normally RED
Describe Illuminating grenade
The illuminating grenade is primarily used by police and Search and Rescue (SAR) teams
and can be operated as both a trip flare and grenade.
What is a Discharger grenade?
- Originally fitted on AFVs to provide an immediate localised smoke screen, their use has now extended to Anti-riot and HE fragmentation variants.
- Electrically initiated, they have a small propelling charge that simultaneously ejects the grenade from the discharger barrel and ignites the main filling.
What is a Projected grenades
- Ever since the introduction of grenades many methods of increasing their range have been developed.
- Projected grenades are categorised as either Rifle or Weapon launched.
What are normal means of delivery of grenades?
- Hand Thrown
- Projected
Rifle launched
Gun fired - Discharger
Weapon launched
Vehicle launched