DS - Armour Flashcards
At what time in flight will the self destruct element initiate on the 25mm Mk2?
5.3 secs in flight
Explain how the projectile of the 25mm Mk2 functions after impact and penetration of the target.
On striking the target the aluminium nose cap of the projectile is crushed.
Provided the velocity of impact and resistance of the target are sufficiently high, the energy generated by the rate of deformation of the cap will be sufficient to raise the incendiary composition to its ignition temperature.
The heat and pressure generated within the projectile then cause the HE to detonate and fragment the steel body.
What is the weight and type of HE fill in the 25mm Mk2?
10g of Comp A4
What are the components that make up the 25mm M791?
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Cart case Primer percussion M115 Ignition booster pellet Propellant WC886 Tracer Base Sabot Penetrator Windshield Nose cap
The 25mm cartridge case consists of:
- Rimless
- Drawn carbon steel
- Painted olive drab / dark green
- Projectile secured by either eight bit or single 360 degree indenting
- A link-locating groove is located below the shoulder
What is the name and details for the 25mm Cart Case primer? (1+2)
Name and weight of booster pellet?
- M115 Primer
- Press fit percussion type
- Punch stabbed or ring indented into position
- A 10g IB52 booster pellet augments the primer
What are the Names for the 25mm Ammunition?
M791 M792 M793 M794 M910 Mk2
Cart 25mm…
...APDS-T M791 ...HEI-T M792 ...TP-T (ADI) M793 ...Dummy M794 ...TPDS-T M910 ...MPSD-T Mk2
Names of the Cart 120mm Ammunition? M830A1 A2 M1028 M865 M831A1 M1002
Cart 120mm HEAT-MP-T M830A1 KE-W A2 120mm APFSDS-T Cart 120mm Canister Anti-Pers M1028 Cart 120mm TPCSDS-T M865 Cart 120mm TP-T M831A1 Cart 120mm TPMP-T M1002
What are the two modes on the fuze fitted to M830A1?
Name the fuze
Air - Prox
Ground - PD
M774 PD
Name the assemblies that make up the propulsion system in ALL 120mm natures.
Case base and seal assembly Spring disc Retaining ring CCC Elec primer (M129 Live/M125 Prac) Combustible disc Propellant JA-2 (Live) M14 (Prac)
What is the quantity, weight and diameter of balls in the Canister round?
1100 x Tungsten balls
Weight 8.3g
9.5mm
What is the V notch for on the Canister round?
Separation of the sidewall after barrel exit
Why is the 120mm Canister frangible?
The projectiles aluminium cap is designed to be frangible so that that it does not interfere with the dispersion of the tungsten balls upon exit from the canister
What does the cone stabiliser on the TPCSDS-T consist of?
Six equally spaced slots
What function does the cone have in the TPCSDS-T?
Impart spin and cause it to lose ballistic stability
At what distance does the TPCSDS-T lose stability?
Within 8000m
What is the fuze used in Cart 25mm HEI-T M792; what type and fill?
PD M774 HMX/PBXN-5
What Targets are the Cart 120mm M830A1
HEAT MP T designed to defeat ?
Light Armoured Vehicles Helicopters Soft Targets (Bunkers)
Prior to loading, what can the Fuze PIBD
M774 be set to ?
Ground (G) point detonating
Air (A) proximity mode
What happens on Firing of the Cart 120mm
M830A1 HEAT MP T Round ?
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- Fuze set prior to loading
- Voltage applied to electric primer (M129)
- Ignites propellant (JA 2), tracer element and CCC
- Gases generated propel projectile down barrel
- Silicon seal at rear of the sabot provides obturation
- Aerodynamic forces cause sabot and obturator to
separate
Setback allows the release mechanism in the
M774 to release rotor from first safe position
Voltage generators activated on setback, charging
the M774 firing capacitor and M74 proximity fuze
capacitor
Deceleration on exiting the barrel allows rotor to
move into the armed position aligning the
explosive train
Target sensed by M74, firing signal is sent to
M774 fuze.
M774 firing capacitor provides energy to initiate
M69 detonator.
M69 detonator initiates fuze lead cup, initiates
booster cup, initiates warhead
Copper jet formed along with shrapnel and blast.
Describe the operation of the 120mm APFSD-T KE W A2
from firing to tar?
Fired electrically thru the M256 Firing System
- Voltage applied to the M129 Primer
- Initiates primers ignition charge to a small gunpowder charge which in turn initiates the primer’s Benite Strands.
- These benite strands are evenly distributed within the primer tube and is designed to give maximum initiation of the main propellant charge JA 2
- JA 2 burns which consumes the CCC and ignites the tracer element
- Expanding gases accelerates the projectile into and thru the barrel
- The steel case base and seal assembly (CBSA) and the primer tube are left behind
- Obturation is provided by the Nylon obturator and seal on the projectile
- Projectile exits Barrel allowing the Sabot/Obturator to peel off and discard
- Leaving the penetrator to travel to the target
Describe the role of the 120mm Canister
round?
The 120mm Canister round is an Antipersonnel round. Offensive fire against exposed enemy Defensive fire against massed infantry assaults