Munitions

Mk238 HEI-T/SD

Also known as
  • 30 mm x 173 HEI-T/SD
  • 30x173mm HEI-T/SD
  • Mk238 HEI-T
  • 30 mm high-explosive incendiary tracer with self-destruct

Northrop Grumman's Mk238 HEI-T/SD is a 30x173 mm high-explosive incendiary tracer cartridge with a self-destruct low-drag fuze, built for the Bushmaster ammunition family. The round is paired with Mk44-class 30 mm cannon applications and sits beside Mk266 HEI-T and Mk239 TP-T in the same Northrop Grumman ammunition suite.

Mk238 HEI-T/SD, 30 mm high explosive incendiary tracer round with self-destruct, Munitions
Image source: 30x173mm Bushmaster Chain Guns
Profile / Specs

Profile

Origin
United States
Type
30 mm high explosive incendiary tracer round with self-destruct
Service note
Modern 30x173mm Bushmaster ammunition family
Produced
Modern production
Developed from
PGU-13 HEI round

Specifications

Caliber
30x173 mm
Designation
Mk238 HEI-T/SD
Cartridge length
290 mm
Cartridge weight
655 g
Projectile weight
362 g
Propellant weight
148 g
Fuze
Self-destruct low-drag fuze
Muzzle velocity
3,540 fps / 1,079 mps
Dispersion
1.0 mr max
Trace time
4.7 sec min
Variants

Mk238 HEI-T/SD is the self-destruct high-explosive incendiary tracer branch inside Northrop Grumman's 30x173 mm Bushmaster ammunition family.

VariantConfigurationDesignation notes
Mk266 Mod 1 HEI-T round, 30 mm high explosive incendiary tracer round, MunitionsMk266 Mod 1 HEI-THigh-explosive incendiary tracer without self-destruct

Northrop Grumman describes Mk266 and Mk238 as PGU-13-derived HEI-T cartridges; Mk266 uses the non-self-destruct low-drag fuze branch while Mk238 uses the self-destruct branch.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure

Mk239 TP-T, 30 mm target practice tracer round, MunitionsMk239 TP-TTarget-practice tracer

Northrop Grumman identifies Mk239 TP-T as a training round ballistically matched to Mk238 HEI-T/SD and Mk266 HEI-T.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure

Mk310 PABM-T, 30 mm programmable air-burst munition with tracer, MunitionsMk310 PABM-TProgrammable air-burst munition with tracer

Mk310 is another 30x173 mm Bushmaster-family round, but it uses programmable airburst, point-detonate, and delay modes rather than Mk238's HEI-T/SD configuration.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure

Ammunition Family

Mk238 HEI-T/SD is one named cartridge in the broader 30x173 mm Bushmaster ammunition suite.

Compatible itemItem typeCompatibility evidence
30 x 173mm suite of ammunition, 30 mm ammunition family, Munitions30 x 173mm suite of ammunition30 mm ammunition family

Northrop Grumman's 30x173 mm family includes Mk238 HEI-T/SD alongside Mk266 HEI-T, Mk239 TP-T, Mk310 PABM-T, and other Bushmaster-compatible cartridges.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure

Firing Weapons

Northrop Grumman places Mk238 HEI-T/SD in the 30x173mm Bushmaster ammunition family for Mk44 guns and related mounts.

Firing weaponWeapon typeFiring evidence
DS30M 30 mm naval gun, Naval gun, Naval SystemsDS30M 30 mm naval gun30 mm naval gun mount

Northrop Grumman says Mk238 HEI-T/SD is used in the Mk44 or any cannon firing 30x173mm ammunition, and MSI identifies the DS30M family with the Mk44 cannon.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure, MSI-DS SEAHAWK DS A2

MK 46 Mod 2 30mm GWS, 30 mm remote gun system, Naval SystemsMK 46 Mod 2 30mm GWS30 mm naval gun weapon system

Northrop Grumman says Mk238 HEI-T/SD is used in the Mk44 or any cannon firing 30x173 mm ammunition, while the U.S. Navy identifies the MK 46 Mod 2 as a shipboard system built around the Mk 44 Mod 2 30 mm cannon.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure, MK 46 - 30 mm Gun Weapon System

Cartridge Context

Mk238 HEI-T/SD is best read as a service cartridge inside a shared 30x173 mm Bushmaster ecosystem rather than as an independent weapon system. The official ammunition-suite brochure separates three useful reader cues: fuze branch, training match, and firing-gun compatibility.

Fuze branch

Mk238 uses the self-destruct low-drag fuze branch, while Mk266 HEI-T uses the non-self-destruct branch.

Training match

Mk239 TP-T is documented as a ballistic training match for Mk238 HEI-T/SD and Mk266 HEI-T.

Gun family

Northrop Grumman places Mk238 in Mk44 or other 30x173 mm cannon use, which supports links to Mk44-class mounts without implying independent conflict use.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure; MSI-DS SEAHAWK DS A2.

Media

Mk238 HEI-T/SD Videos

Mk238 HEI-T/SD Images

Mk238 HEI-T/SD, 30 mm high explosive incendiary tracer round with self-destruct, Munitions - view 1
Source: 30x173mm Bushmaster Chain Guns
Related Weapon Systems
M940 MPT-SD cartridge, 20 mm multi-purpose tracer self-destruct cartridge, MunitionsMunitionsM940 MPT-SD cartridge20 mm multi-purpose tracer self-destruct cartridgeThe M940 MPT-SD is a U.S. 20x102 mm multi-purpose tracer self-destruct cartridge for the land-based Phalanx / C-RAM firing chain. Northrop Grumman identifies M940-1 and M940-2 as C-RAM-fired rounds, Army ammunition material describes LPWS/C-RAM employing M940 against incoming rockets, artillery shells, and mortar rounds, and FY2027 budget material lists AC34 M940 w/MK7 Link procurement through Northrop Grumman and General Dynamics option lines.
30 mm x 165 HEI-T round, 30x165 mm high-explosive incendiary tracer cartridge, MunitionsMunitions30 mm x 165 HEI-T round30x165 mm high-explosive incendiary tracer cartridgeThe 30 mm x 165 HEI-T round is a Soviet-origin high-explosive incendiary tracer cartridge in the 30x165 mm autocannon family, with the 3UOR6 designation used for a closely documented Russian-service round. STV GROUP, MSM Group, Yugoimport, METIS, and ordnance references tie the cartridge family to 2A38, 2A42, and 2A72 automatic cannons, making the round relevant to BMP-2, BMP-3, BMD-family, BTR-80A, Tunguska, and other 30x165 mm gun platforms.
M1147 120 mm advanced multipurpose round, 120 mm high-explosive multipurpose tank cartridge, MunitionsMunitionsM1147 120 mm advanced multipurpose round120 mm high-explosive multipurpose tank cartridgeThe M1147 AMP, formally a 120 mm High Explosive Multi-Purpose with Tracer cartridge, is a U.S. multipurpose tank round for Abrams crews. Army, DOT&E, and budget material describe it as an Abrams-employed line-of-sight munition that consolidates several legacy 120 mm cartridge roles into a programmable round with point-detonate, delayed, and airburst settings, while a 2026 contract notice shows production planned for U.S. Army and possible Foreign Military Sales customers.

Sources

30x173mm Bushmaster Chain GunsPublisher: Northrop Grumman | Note: Supports official image provenance, 30x173mm Bushmaster family background, official video context, and the Mk44 cannon context used for Mk238 HEI-T/SD. | Accessed: 2026-07-02Northrop Grumman 30x173mm Full Ammo Suite BrochurePublisher: Northrop Grumman | Note: Supports the Mk238 HEI-T/SD designation, cartridge dimensions and weights, muzzle velocity, trace time, and self-destruct ammunition-family context. | Accessed: 2026-07-02MSI-DS SEAHAWK DS A2Publisher: MSI-Defence Systems | Note: Supports the DS30M Mk 44 cannon context and the naval mount compatibility relationship. | Accessed: 2026-07-02MK 46 - 30 mm Gun Weapon SystemPublisher: U.S. Navy | Note: Supports the MK 46 Mod 2 30 mm gun weapon system as a shipboard Mk 44 Mod 2 cannon application for the firing-weapon relationship. | Accessed: 2026-07-02