Cartridges and Projectiles Flashcards
What are the components that make up the Breech Loading System?
BL (Tubes, bagged chgs, projo)
QF (CC & primer, prop charge, projo)
How is obturation achieved using the BL/QF (or AO) system?
BL – rearward obturation is achieved by the gun.
QF – rearward obturation provided by cartridge case.
‘protection of the contents’is one of the main requirements of the Cart Case. Name three others
Holds the primer
Provides obturation
Ease of extraction
Explain how separate ammunition loaded into a breech loaded weapon systems?
The projectile and the charge bages are loaded into the chamber of the gun. The breech is closed to provide obturation. Tube or primer is inserted into the breech.
155mm Howitzer ammunition.
List the four types of bagged charges.
Equal cylinder
Steam and ring
Unequal cylinder
Steam and segmented
What are the types of QF cart systems?
Fixed cart (CC and projo joined)
Semi fixed (partes mated before ramming)
Separate (mated in gun)
Adv of QF sep/Semi-fixed over QF fixed = adjust charge, can replace damged cc, less stowage problems due to reduction in length)
What are the two main types of metal defects?
- Mechanical (Cracking due to stress)
- Chemical (Corrosion due to impurities)
What are the five different types of corrosion
- Rust (Ferrous Oxide)
- Aluminium Oxidation
- Mazak Contamination
- Zinc Exudation
- Cupric Azide
What are the four main methods of filling HE Shell?
- Casting
(straight poor, creamed, liquid & biscuit) - Pressing
(pressing, pre-pressed charges, incrementally into case) - Extruding
(direct extrusion into case) - Preforming/cocooning
(land mines)
What are the three methods of casting explosives?
- Straight pour
- Creamed
- Liquid and Biscuits
Driving bands are one application that use copper in ammunition. List three others
Driving Bands
Detonators
Shaped charge liners
CC
SAA Jackets
What alloys in which percentage make up a brass cartridge?
70% copper
30% zinc
What are the three classifications of tracers?
- Tracer Projectile (emit light)
- Tracer and Igniter Projectile (self destruct)
- Integral Tracer (SAA)
A typical 1960s Exploder systm consisted of an aluminium canned CE pellet which provided three main benefits over the previous systems. One of them was ‘no explosive migration’ list the other two
Ease of removal
Setback forces eliminated
No migration of explosive.
Why do we use brass in cart cases
Non-corrosive, no abrasive particles
Reliable across equipment
Well-established metallurgy and techniques
What advantage does a combustible cart case offer
All chambered components affect ballistics
Reduces barrel wear and cook-off
Minimizes residue
Lighter ammo
List three means of attaching cartridge cases to a projectile?
Coning
Cannularing
Combo of both
What are the two means of ignition for tracer rounds?
- Direct Ignition
- Propellant Ignition
Methods of sealing tracer
Brass or celluloid discs or cups
NG and carbamite
Bakelite discs
Sealing methods can vary considerably
Tracer and igniter shells are made from steel or brass rod bored out to accomodate which parts?
Primer composition
Tracer composition
Ignitor composition
What are the functions of driving bands ?
- To centre projectile in bore and impart spin in rifling
- To prevent the forward escape of propellant gases
- To prevent slip back of the projectile when loaded at high elevations
What are the methods of preventing twisting in driving bands?
- Wavy rib
- Knurling
One of the design requirements for a driving band is that it places no excessive pressure on the barrel or shell. Name FOUR other requirements.
- 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
What are the two types of primers?
- Precussion
- Conducting Cap (Electric Primers)
What are the four main components of a Conducting Cap Electric Primers
- Magazine
- Pole Unit
- Base
- Cap
What are the four types of natural fibres used within ammunition?
- Cellulose (Cotton, wood/paper)
- Silk
- Wool
- Rubber and Synthetic Rubbers
What are the two main types of plastics used with ammunition? And what is the main difference between them?
- Thermoplastic (softens on heating, can be reshaped)
- Thermosetting Plastic (incapable of being softened by heat)
Thermoplastic can be reheated and reshaped whereas Thermosetting plastic is incapable of again being softened by heat.
What is used for non-permanent seals?
Luting
Operation projectiles are one of the classifications of projectiles. Give one other
Operational projectiles
Weapon functioning / inspection
Training projectiles
What are the three methods of HE shell manufature?
Cast
Forged
Extruded
What is the definition of a carrier shell?
Those in which the body is used as a vehicle conveying a payload to the target.
What are 2 types of recoilless rifle rounds
Blow out disc (pressure builds, disk ruptures, proj propelled fwd, prop gases escape through breech hole and out venturi)
Perforated cart case (prop gases excape through holse in CC into annualr space, out through venturi)
What is the definition of corrosion?
Conversion of a metal to a non-metallic state
What is base bleed?
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%
Explain Rocket Assisted Projectile
Before loading, the rocket cap is removed. Firing ignites a 7-second delay, then the igniter and main motor. The booster lasts 2 seconds, sustain 7 seconds, with gases vented through the venturi.
What are the components of a projectile?
