Naval Systems

DS30M 30 mm naval gun

Also known as
  • DS30M
  • 30mm DS30M Mark 2
  • DS30M Mark 2
  • Automated Small Calibre Gun
  • ASCG
  • MSI-DS SEAHAWK DS A2

The DS30M is a British shipborne 30 mm automated small-calibre gun mount built around the Mk 44 Bushmaster II cannon and MSI-Defence Systems' Seahawk mount architecture. It gives patrol vessels, auxiliaries, frigates, and destroyers a remotely controlled close-in gun for fast surface threats, drones, and force protection. In the 2023 Red Sea Crisis, HMS Diamond's crew used a 30 mm cannon against a Houthi drone while protecting merchant shipping.

DS30M 30 mm naval gun, Naval gun, Naval Systems
Image source: HMS Medway fires its 30mm gun

Role in Conflicts

Profile / Specs

Profile

Origin
United Kingdom
Type
Naval gun
Service note
2007-present
Designer
MSI-Defence Systems
Designed
2000s
Produced
2000s-present

Specifications

Caliber
30 mm
Gun
Mk 44 Bushmaster II
Cartridge family
30 x 173 mm Bushmaster ammunition
Feed
Dual or single feed, depending on mount fit
Mount control
Remote electro-optical control with local reversion available
Ammunition capacity
Up to 400 rounds on the MSI-DS SEAHAWK DS A2 family
Primary roles
Close-in ship protection against fast surface craft, drones, and other short-range threats
Mount And Fire-Control Layout

The DS30M family combines the Mk 44 30 mm chain gun with a stabilized MSI naval mounting and electro-optical fire-control path. That layout lets the ship keep the gun crew under cover while retaining local backup control at the mount when required.

Cannon core

Mk 44 Bushmaster II, a 30 x 173 mm chain-gun family used on naval and ground platforms.

Sources: MSI-DS SEAHAWK DS A2; 30x173mm Bushmaster Chain Guns.

Control path

Remote electro-optical control is central to the mount, with local reversion available for backup operation.

Sources: MSI-DS SEAHAWK DS A2; U.S. Navy and Coast Guard Moving to Adopt Mark 44 30mm on MSI Mount.

Ammunition fit

The related Seahawk DS A2 family supports single-feed or dual-feed ammunition arrangements, with published MSI-derived reporting listing up to 400 ready rounds.

Sources: MSI-DS SEAHAWK DS A2; U.S. Navy and Coast Guard Moving to Adopt Mark 44 30mm on MSI Mount.

Variants

DS30M naming is used for Royal Navy 30 mm automated mounts, while MSI-DS markets the broader Seahawk DS A2 family around the same stabilized naval-gun architecture.

VariantConfigurationDesignation notes
DS30M Mark 2Royal Navy automated small-calibre gun mount

The Mark 2 configuration is the 30 mm automated mount associated with Royal Navy ship-protection fits and the Mk 44 Bushmaster II cannon.

Sources: The 30mm Automated Small Calibre Gun in focus, MSI-DS SEAHAWK DS A2

MSI-DS SEAHAWK DS A2Manufacturer family designation

MSI-Defence Systems uses the SEAHAWK DS A2 designation for the stabilized mount and electro-optical control family that includes 30 mm cannon configurations.

Sources: MSI-DS SEAHAWK DS A2

Ammunition Fired

The DS30M family uses the Mk 44 cannon, and Northrop Grumman places that gun in its 30x173mm Bushmaster ammunition family.

AmmunitionAmmunition typeFiring evidence
30 x 173mm suite of ammunition, 30 mm ammunition family, Munitions30 x 173mm suite of ammunition30 mm ammunition family

MSI's SEAHAWK DS A2 page identifies the DS30M family with the Mk 44 cannon, and Northrop Grumman describes 30x173mm advanced ammunition as the Bushmaster chain-gun family.

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

Mk238 HEI-T/SD, 30 mm high explosive incendiary tracer round with self-destruct, MunitionsMk238 HEI-T/SD30 mm HEI-T/SD round

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

Mk310 PABM-T, 30 mm programmable air-burst munition with tracer, MunitionsMk310 PABM-T30 mm programmable air-burst round

Northrop Grumman says the Mk310 PABM-T is designed for the Bushmaster Mk44 cannon family used by the DS30M mount.

Sources: Northrop Grumman 30x173mm Full Ammo Suite Brochure, 30x173mm Bushmaster Chain Guns

Mk239 TP-T, 30 mm target practice tracer round, MunitionsMk239 TP-T30 mm target practice-tracer round

Northrop Grumman says Mk239 TP-T was developed for ground vehicle applications that use Mk44 cannons 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

Mk266 Mod 1 HEI-T round, 30 mm high explosive incendiary tracer round, MunitionsMk266 Mod 1 HEI-T round30 mm HEI-T round

The DS30M family uses the Mk 44 cannon, and Northrop Grumman identifies Mk266 HEI-T as a 30x173mm round usable in Mk44 or any cannon firing 30x173mm ammunition.

Sources: MK 266 Mod 1 HEI-T - PEO Ammunition, MSI-DS SEAHAWK DS A2

Timeline

DS30M 30 mm naval gun Key Events

  1. UK DS30M Mark 2 retrofit order

    The UK Ministry of Defence awarded MSI-Defence Systems a contract for 26 DS30M Mark 2 automated small-calibre gun systems for Type 23 frigate retrofits.

    Sources: The 30mm Automated Small Calibre Gun in focus

  2. Royal Navy reports Red Sea close-in gun use

    The Royal Navy reported that HMS Diamond's crew had used a 30 mm cannon to shoot down a Houthi drone during its Red Sea and Gulf of Aden deployment.

    Sources: HMS Diamond shoots down Houthi missile

Media

DS30M 30 mm naval gun Images

DS30M 30 mm naval gun, Naval gun, Naval Systems - view 1
Source: HMS Northumberland DS30M at West India South Dock
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Sources

MSI-DS SEAHAWK DS A2Publisher: MSI-Defence Systems | Note: Supports DS30M family background, manufacturer context, mount controls, and 30 mm gun configuration. | Accessed: 2026-07-04The 30mm Automated Small Calibre Gun in focusPublisher: Navy Lookout | Note: Supports DS30M Mark 2 service context and the 2005 UK Ministry of Defence contract for Type 23 frigate retrofit systems. | Accessed: 2026-07-04U.S. Navy and Coast Guard Moving to Adopt Mark 44 30mm on MSI MountPublisher: Naval News | Note: Supports MSI naval mount architecture context, remote/local control concepts, electro-optical sighting, and feed/ammunition-capacity details for the related Mk44-on-MSI mount family. | Accessed: 2026-07-04HMS Diamond shoots down Houthi missilePublisher: Royal Navy | Note: 2023 Red Sea Crisis: documents Royal Navy destroyer HMS Diamond using a 30 mm cannon to shoot down a Houthi drone while deployed to protect merchant shipping. | Accessed: 2026-07-04HMS Medway fires its 30mm gunPublisher: Wikimedia Commons | Note: Supports image provenance and public-domain licensing for the DS30M mount shown on HMS Medway. | Accessed: 2026-07-04HMS Northumberland DS30M at West India South DockPublisher: Wikimedia Commons | Note: Supports image provenance and public-domain licensing for a second DS30M shipboard view. | Accessed: 2026-07-0430x173mm Bushmaster Chain GunsPublisher: Northrop Grumman | Note: Supports the Mk 44 cannon family context and the 30x173mm ammunition relationship used by the DS30M mount. | Accessed: 2026-07-04Northrop Grumman 30x173mm Full Ammo Suite BrochurePublisher: Northrop Grumman | Note: Supports Mk238 HEI-T/SD and Mk310 PABM-T designation details, cartridge data, fuze modes, and Mk44 compatibility. | Accessed: 2026-07-04MK 266 Mod 1 HEI-T - PEO AmmunitionPublisher: PEO Ammunition / U.S. Army | Note: Supports the reciprocal Mk266 HEI-T relationship and the 30x173mm compatibility language used in the pairing note. | Accessed: 2026-07-04