25mm Ammunition Flashcards
Ammunition Natures selected for use with the ASLAV25 Bushmaster M242 Weapon system in service are:
Armour Piercing Discarding Sabot with Tracer (APDS T) M791
Target Practice Discarding Sabot Tracer
(TPDS T) M910
Multipurpose with Tracer Self Destruct Mk 2 (MPT SD Mk2)
High Explosive Incendiary Tracer M792
Target Practice with Tracer (TP T) (ADI) M793
Dummy M794
25mm cart case characteristics:
Rimless drawn 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
25mm primer characteristics:
M115 press fit percussion type
Punch stabbed or ring indented into position
A 10g IB52 booster pellet augments the primer
25mm propellant characteristics:
overseas produced ammunition
Approximately 90g of Olin WC890 Ball Powder
local production
single based ADI AR2220 propellant
Ranges of Armour Piercing Discarding Sabot
with Tracer (APDS T) M791
Suitable for engaging soft skinned
targets at greater than 1500m
Hard types of cover, such as concrete
structures, at greater than 1000m.
Parts of the Armour Piercing Discarding Sabot with Tracer (APDS T) M791
Projectile body consists of:
A solid tungsten alloy penetrator of 12.7mmdiameter
Pressed on aluminium windscreen
Pressed in tracer pellet that burns for a
minimum of 1.4 seconds
Moulded discarding type nylon sabot
Pressed on polyethylene nose cap
Muzzle velocity of the projectile is 1345 m/s
Markings of the 25mm Armour Piercing Discarding Sabot with Tracer (APDS T) M791
Projectile / Sabot
Black with white markings
Cart Case
Dark Green / olive drab with
manufacture details and year (last two
digits) stamped into base
25mm Target Practice Discarding Sabot with Tracer (TPDS T) M910 is ballistically matched to which nature?
Ballistically matched to Armour Piercing Discarding Sabot with Tracer (APDS T) M791 to 2000m
Armour Piercing Discarding Sabot
with Tracer (APDS T) M791
Parts of the Target Practice Discarding Sabot with Tracer (TPDS T) M910
Projectile body consists of:
A solid steel core penetrator (sub projectile) encased in a mouldered nylon sabot (aluminium base)
Pressed on Polyethylene Nose Cap
Pressed in tracer pellet that burns for a
minimum of 1.4 seconds
Muzzle velocity of the projectile is 1520 m/s
Functioning of 25mm Target Practice Discarding Sabot with
Tracer (TPDS T) M910
Firing pin initiates primer
Which ignites booster pellet & propellant
Gases propel projectile forward simultaneously igniting tracer element
Spin of projectile on barrell exit causes separation of sabot and sub projectile
Sub projectile spin stabilised
High mass flow tracer decreases base drag allowing sub projectile to balistically match to M791 to range of 2000m
Markings Target Practice Discarding Sabot with Tracer (TPDS T) M910
Projectile
Blue with white markings
Cart Case
Dark Green / olive drab withmanufacture details and year (last two digits) stamped into base
Parts of a Multipurpose with Tracer
Self Destruct (MPT SD Mk2)
The projectile comprises of:
An aluminium nose cap incorporating a support disc and RS38 / RS41 Incendiary Mixture of 2.7g
Nose cap separated from main charge by support disc with 3mm flash channel
Boron steel (strengthened) fully heat treated body
Integral traced/self destruct element (magnesium)
Sintered iron driving band
Main charge consists of:
Press filled incendiary of 9g of RS40
10g high explosive Comp A4
Tracer/self destruct (3 stage) comprising
of:
RS56 Igniter, RS55 Subigniter,& RS42/54 Tracer Composition
Tracer protected with a sealing disc
Functioning of MPT SD Mk2
On firing tracer igniter initiated via propellant
gases/heat and projects projectile from barrell
Spin / heat causes RS38 / RS41 mix to change
in consistency
Friction through air heats nose cap critical
On impact nose cap is crushed (threshold
velocity of 250m/s (min) required to initiate
RS38/41mix) critical
Compression of void in nose cap raises temp of RS38/41 to ignition point (approx 500 deg C)
RS38/41 mix ignites and flashes through support disc and:
initiates main fill of RS40 incendiary & Comp A4 HE compositions
causing heat / flame / blast and fragmentation effect at the target
Should target be missed, self destruct is initiated by tracer igniter after 5.3 secs of flight.
NOTE: Delay of 0.3 millisec allows strengthened projectile to penetrate skin of target before detonating creating blast fragmentation & incendiary effects behind or inside target
Self Destruct Function of 25mm MPT SD Mk2
At shot start:
Closure disc disrupted
tracer comp ignited
Proceeds to burn in flight
Sufficient heat generated to function Comp A4 filled self destruct well
Normal burn time to self destruct not less than 5.3seconds or 2500m
Self destruct feature eliminates collateral damage following engagement of aerial targets