Munitions

L31 HESH round

Also known as
  • L31A7
  • L31A7 HESH
  • HESH L31
  • 120 mm L31A7 HESH
  • 120mm HESH round
  • 120 mm HESH L31
  • High-explosive squash head L31

The L31 HESH round is a British 120 mm high-explosive squash-head projectile for rifled Royal Ordnance tank guns, including the Challenger 2's L30A1. RO Defence/Jane's describes it as a general-purpose round for armor, fortifications, structures, and possible indirect fire, while 2003 Iraq War reporting documents Challenger 2 HESH fire in a 2003 Basra-area fratricide incident.

L31 HESH round, 120 mm HESH shell, Munitions
Image source: 120MM HESH Round.jpg

Role in Conflicts

Profile / Specs

Profile

Origin
United Kingdom
Type
120 mm HESH shell

Specifications

Caliber
120 mm
Projectile type
High-explosive squash head (HESH)
Designation
L31A7
Gun family
L30A1 rifled tank gun
Compatible British guns
L11 and L30A1 rifled 120 mm tank guns
Loading
Separate-loaded projectile with propelling charge and electric vent tube
Propelling charge
CP SH L3A2 for HESH, smoke, and squash-head practice rounds
Explosive fill
About 4.2 kg RDX/wax in a thin-walled projectile
Maximum range cited
Up to 8,500 m
Muzzle velocity
670 m/s
Firing Weapons

The L31 is documented in the British rifled 120 mm tank-gun ammunition family and in the Challenger 2 ammunition fit.

Firing weaponWeapon typeFiring evidence
Challenger 2, Main battle tank, TanksChallenger 2Main battle tank

Challenger 2 uses the L30A1 rifled gun, and the RO Defence/Jane's ammunition profile identifies HESH L31 in the Royal Ordnance 120 mm family used with the L11 and L30A1 gun lineage.

Sources: RO Defence 120mm tank gun ammunition, Challenger 2 Castlemartin Service Inquiry

Round And Firing Chain

The L31 is not a one-piece cartridge. In Challenger 2 service context, the projectile is loaded with a separate propelling charge and an electric vent tube that initiates the main charge in the L30A1 gun.

ElementRoleDocumented detail
L31/L31A7 projectileOperational HESH projectileRO Defence/Jane's describes a thin-walled, RDX/wax-filled squash-head projectile for armor, fortifications, structures, and possible indirect fire.
CP SH L3A2Propelling chargeThe Defence Safety Authority service inquiry identifies CP SH L3A2 as the charge used for HESH, smoke, and squash-head practice rounds in Challenger 2 main-armament context.
L4A2 electric vent tubeInitiating chargeThe same inquiry identifies the L4A2 tube vent electric as the initiating charge for the Challenger 2 L30A1 gun.
Timeline

L31 HESH round Key Events

  1. RO Defence ammunition profile

    Jane's profiled RO Defence 120 mm tank-gun ammunition and described HESH L31 as part of the rifled L11/L30A1 ammunition family.

  2. HESH fired in 2003 Iraq War incident

    Operation Iraqi Freedom reporting and the catalogd Challenger 2 Board of Inquiry record cover the Basra-area incident in which HESH rounds were fired by a British Challenger 2 crew.

  3. Challenger 2 firing-chain details published

    The Defence Safety Authority service inquiry described the Challenger 2 L30A1 gun, HESH definition, CP SH L3A2 propelling charge, and L4A2 electric vent tube.

Media

L31 HESH round Images

L31 HESH round, 120 mm HESH shell, Munitions - view 1
Source: Arjun tank's HESH round impacting an armour block.jpg
Related Weapon Systems
120 mm L2 HESH, 120 mm high-explosive squash-head recoilless-rifle ammunition, MunitionsMunitions120 mm L2 HESH120 mm high-explosive squash-head recoilless-rifle ammunitionThe 120 mm L2 HESH round was the high-explosive squash-head ammunition for Britain's BAT-family recoilless anti-tank rifles, pairing a separate-loaded 120 mm projectile and propellant case with the L2 BAT, L4 MOBAT, and L6 WOMBAT family. A 1964 joint-services ammunition-marking handbook identifies the service store as 120 mm B.A.T. H.E.S.H. L19A3, while specialist sources use the L2 HESH label for the BAT-family round. Australian War Memorial collection data documents BAT HESH ammunition tubes with an L4 MOBAT in Malacca during the Indonesian Confrontation, giving the round a direct source-backed conflict context without implying that the specific photographed rounds were fired.
76mm HEP-T M329, 76 mm fixed HESH-T / HEP-T tank-gun round, MunitionsMunitions76mm HEP-T M32976 mm fixed HESH-T / HEP-T tank-gun roundThe 76mm HEP-T M329 is a MECAR high-explosive squash head service round for the British L5A1 and L23/L23A1 76 mm gun family used on Saladin and Scorpion vehicles. Nexter's 2016 ammunition catalog lists it as an in-service fixed HESH-T round for personnel, bunkers, light armour, structures, and other material targets, with a Composition A3-filled projectile, base-detonating graze fuze, M23 tracer, and 533 m/s nominal muzzle velocity.
120 mm high-explosive anti-tank ammunition, 120 mm high-explosive anti-tank ammunition for rifled gun-mortars, MunitionsMunitions120 mm high-explosive anti-tank ammunition120 mm high-explosive anti-tank ammunition for rifled gun-mortars120 mm high-explosive anti-tank ammunition is the direct-fire anti-armor round class used by Soviet and Russian rifled gun-mortars in the Nona family. Forecast International identifies the 2S23 Nona-SVK's 2A60 weapon as firing HEAT ammunition for direct-fire applications, while specialist munition references identify the 3VBK14/3BK19 round as a documented 120 mm HEAT-FS-T load for armored-target engagements.

Sources

RO Defence 120mm tank gun ammunitionPublisher: Jane's Defence News | Note: Describes RO Defence 120 mm tank-gun ammunition, L11/L30A1 gun context, HESH L31 role, construction, explosive fill, charge context, and cited range. | Accessed: 2026-06-29Challenger 2 Castlemartin Service InquiryPublisher: UK Ministry of Defence | Note: Defines HESH in Challenger 2 main-armament context and identifies the L30A1 gun, CP SH L3A2 propelling charge, and L4A2 electric vent tube. | Accessed: 2026-06-29Blue on Blue - Ground Incidents during Operation Iraqi FreedomPublisher: Defense Update | Note: Directly supports 2003 Iraq War conflict use by reporting that a British Challenger II fired HESH rounds in the Basra-area fratricide incident during Operation Iraqi Freedom. | Accessed: 2026-06-29Challenger 2 25 March 2003 Board of InquiryPublisher: UK Ministry of Defence | Note: Archived official Board of Inquiry for the 25 March 2003 Challenger 2 incident near Basra, supporting the 2003 Iraq War incident context for the conflict-use row. | Accessed: 2026-06-29House of Commons Defence Committee depleted uranium evidencePublisher: UK Parliament | Note: Provides British parliamentary background on 120 mm HESH ammunition in British tank service and its relationship to the CHARM system. | Accessed: 2026-06-29Wikipedia Challenger 2Publisher: Wikipedia | Note: Lists L31 HESH among Challenger 2's carried rounds and gives the tank's 120 mm rifled-gun context. | Accessed: 2026-06-29Royal Ordnance L30Publisher: Wikipedia | Note: Describes the L31A7 HESH projectile as part of the L30 ammunition family and gives muzzle velocity and loading context. | Accessed: 2026-06-29GlascoedPublisher: BAE Systems Heritage | Note: Covers the Glascoed ammunition site and its production of 120 mm tank ammunition for Chieftain and Challenger, supporting the Royal Ordnance/RO Defence manufacturing lineage. | Accessed: 2026-06-29120MM HESH Round.jpgPublisher: Wikimedia Commons | Note: Supports primary image provenance for the HESH round cross-section photograph hosted on Wikimedia Commons. | Accessed: 2026-06-29Arjun tank's HESH round impacting an armour block.jpgPublisher: Wikimedia Commons | Note: Supports gallery image provenance for a reusable Wikimedia Commons HESH-impact photograph. | Accessed: 2026-06-29