During 2014 Operation Inherent Resolve, U.S. Air Force imagery documented special mission aviators loading 30 mm ammunition aboard an AC-130W Stinger II on July 23, 2018; Northrop Grumman identifies the GAU-23/A Bushmaster II as the aircraft version of the Mk44 in its 30x173 mm family.
Role detailsMunitions
30 x 173mm suite of ammunition
Also known as
- 30x173mm ammunition suite
- 30x173mm advanced ammunition
- 30 mm x 173 mm suite of ammunition
- 30x173mm Bushmaster ammunition
- 30mm x 173mm full ammo suite
Northrop Grumman's 30x173 mm Bushmaster ammunition family covers high-explosive, practice-tracer, programmable airburst, and armor-piercing round types for Mk44, Mk44 Stretch, XM813, and GAU-23/A cannon applications. The suite is better read as a cartridge family than as one round: this record links the ammunition to shipboard mounts, AC-130 gunship use, and the catalog's individual Mk238, Mk239, Mk266, and Mk310 round pages.
Role in Conflicts
Profile / Specs
Profile
- Origin
- United States
- Built by
- Northrop Grumman
- Type
- 30 mm ammunition family
- Service note
- Modern Bushmaster chain-gun ammunition family
- Produced
- Modern production
Specifications
- Caliber
- 30x173 mm
- Ammunition family
- Northrop Grumman Bushmaster advanced ammunition suite
- Compatible gun family
- Mk44, Mk44 Stretch, XM813, and GAU-23/A Bushmaster applications
- Documented round examples
- Mk238 HEI-T/SD, Mk239 TP-T, Mk266 Mod 1 HEI-T, and Mk310 PABM-T
- Documented effects
- High-explosive incendiary tracer, training tracer, programmable airburst, and armor-piercing loadings
- Naval mount capacity example
- 400 rounds on MSI-DS SEAHAWK DS A2 and U.S. Navy MK 46 Mod 2 contexts
Variants
The suite groups multiple 30x173 mm cartridge designs around the same Bushmaster-family case and cannon compatibility rather than around a single tactical effect.
| Variant | Configuration | Designation notes |
|---|---|---|
 | High-explosive incendiary tracer with self-destruct | Northrop Grumman lists Mk238 HEI-T/SD as a 30x173 mm round for Mk44 or other cannons firing 30x173 mm ammunition. |
 | Target-practice tracer | The Mk239 TP-T page documents the training round as part of the Northrop Grumman 30x173 mm suite and as a ballistic match for operational HEI-T rounds. |
 | High-explosive incendiary tracer | U.S. Army ammunition documentation identifies Mk266 Mod 1 HEI-T as a 30x173 mm cartridge used in shipboard gun systems. Sources: MK 266 Mod 1 HEI-T - PEO Ammunition |
| Programmable air-burst munition with tracer | Northrop Grumman describes Mk310 PABM-T as a programmable 30x173 mm Bushmaster-family round with airburst, point-detonate, and delay modes. |
Firing Weapons And Mounts
The 30x173 mm family appears across aircraft, naval, and ground-vehicle Bushmaster cannon applications rather than one fixed launcher.
| Firing weapon | Weapon type | Firing evidence |
|---|---|---|
 | Armed gunship | DVIDS documents 30 mm ammunition loaded aboard an AC-130W Stinger II during 2014 Operation Inherent Resolve, and Northrop Grumman identifies the GAU-23/A Bushmaster II as a 30x173 mm aircraft application. Sources: AC-130W 30mm Ammo Loading During OIR, 30x173mm Bushmaster Chain Guns |
 | 30 mm naval gun weapon system | The U.S. Navy identifies the MK 46 Mod 2 as a remotely operated Mk 44 Mod 2 30 mm gun system with a dual-feed 400-round magazine, matching the Bushmaster 30x173 mm ammunition family context. Sources: MK 46 - 30 mm Gun Weapon System, 30x173mm Bushmaster Chain Guns |
 | 30 mm naval gun mount | MSI's SEAHAWK DS A2 page documents the DS30M family with 30 mm cannon options and 400-round ammunition capacity, while Northrop Grumman identifies 30x173 mm advanced ammunition as the Bushmaster chain-gun family. Sources: MSI-DS SEAHAWK DS A2, 30x173mm Bushmaster Chain Guns |
Family Structure
The 30x173 mm suite covers a common cartridge family used across related Bushmaster cannon applications. The operational effect depends on the round selected: explosive, practice, programmable airburst, armor-piercing, or other specialized loading.
| Application | Documented connection | Page context |
|---|---|---|
| AC-130W Stinger II | DVIDS documents 30 mm ammunition loaded aboard an AC-130W during 2014 Operation Inherent Resolve; Northrop Grumman identifies GAU-23/A as a 30x173 mm Bushmaster II application. | |
| MK 46 Mod 2 GWS | The U.S. Navy identifies the system as a Mk 44 Mod 2 30 mm naval gun weapon system with a dual-feed 400-round magazine. | |
| DS30M / SEAHAWK DS A2 | MSI-Defence Systems lists SEAHAWK DS A2 with 25 mm, 30 mm, and 40 mm cannon options and a 400-round ammunition capacity, while the cataloged DS30M page ties the mount to the Mk 44 cannon. | |
Timeline
30 x 173mm suite of ammunition Key Events
AC-130W ammunition loading documented during OIR
U.S. Air Force imagery showed 30 mm ammunition being loaded aboard an AC-130W Stinger II in support of 2014 Operation Inherent Resolve.
Sources: AC-130W 30mm Ammo Loading During OIR
Media
30 x 173mm suite of ammunition Videos
30 x 173mm suite of ammunition Images
Related Weapon Systems
Sources
AC-130W 30mm Ammo Loading During OIRPublisher: Defense Visual Information Distribution Service | Note: Supports 2014 War Against the Islamic State direct conflict use under Operation Inherent Resolve: Directly supports 2014 Operation Inherent Resolve conflict use by documenting 30 mm ammunition loaded aboard an AC-130W Stinger II on July 23, 2018, and supports public-domain image provenance for the primary image. | Accessed: 2026-06-2930x173mm Bushmaster Chain GunsPublisher: Northrop Grumman | Note: Supports the 30x173 mm advanced ammunition family, Bushmaster chain-gun context, compatible gun-family framing, manufacturer background, and official product images used on this page. | Accessed: 2026-06-29Northrop Grumman 30x173mm Full Ammo Suite BrochurePublisher: Northrop Grumman | Note: Supports the named 30x173 mm full ammunition suite, round-designation structure, and same-family Mk238, Mk239, and Mk310 context. | Accessed: 2026-06-29MK 266 Mod 1 HEI-T - PEO AmmunitionPublisher: PEO Ammunition / U.S. Army | Note: Supports the Mk266 Mod 1 HEI-T designation, 30x173 mm cartridge context, and shipboard gun-system service background used in the family table. | Accessed: 2026-06-29MK 46 - 30 mm Gun Weapon SystemPublisher: U.S. Navy | Note: Supports the MK 46 Mod 2 Mk 44 cannon relationship, remote gun-system context, dual-feed magazine, and 400-round capacity used for naval compatibility. | Accessed: 2026-06-29MSI-DS SEAHAWK DS A2Publisher: MSI-Defence Systems | Note: Supports the DS30M/SEAHAWK DS A2 naval mount context, cannon option framing, and 400-round ammunition capacity relationship. | Accessed: 2026-06-29