Breaking News
Northrop Grumman Begins Full Production of Mk44S Guns for U.S. Marines’ ACV-30 Amphibious Vehicles.
Northrop Grumman has entered full-rate production of its Mk44 Stretch Bushmaster Chain Gun for the U.S. Marine Corps’ Amphibious Combat Vehicle-30 variant, the company confirmed on December 16, 2025. The move strengthens Marine littoral forces at a time when amphibious units are central to U.S. crisis response and deterrence operations, including in the Caribbean.
On December 16, 2025, Northrop Grumman announced it has entered full-rate production of its Mk44 Stretch Bushmaster Chain Guns for the U.S. Marine Corps’ new Amphibious Combat Vehicles. This step marks the transition from development and low-rate initial production to sustained industrial output for the ACV-30 variant, which will be fitted with a Kongsberg remote turret. At a time when the Marine Corps is refocusing on littoral operations and crisis response, giving its amphibious vehicles a medium-caliber cannon with long reach and programmable ammunition directly relates to emerging threats ranging from drones to fast attack craft. The announcement gains added weight against the backdrop of mounting U.S.–Venezuela tensions and an expanded American naval presence in the Caribbean, where amphibious forces are one of Washington’s primary tools for signaling and intervention.
The shift to full-rate Mk44S production for the ACV-30 quietly but clearly strengthens the Marine Corps’ ability to project measured, credible force from the sea at a time when crisis scenarios in the Caribbean are no longer hypothetical (Picture Source: Northrop Grumman)
The Mk44 Stretch Bushmaster, or Mk44S, is the latest evolution of Northrop Grumman’s 30×173 mm chain gun family, itself derived from the widely fielded 25 mm M242. It uses an externally powered chain drive, which decouples firing from recoil forces and is known for high reliability in harsh environments, a key requirement for salt-spray, high-humidity amphibious operations. The Mk44S can fire the full spectrum of NATO-standard 30×173 mm ammunition, including armor-piercing sabot, high-explosive and programmable air-burst munitions such as Northrop Grumman’s Mk310 round, designed to engage infantry in defilade, drones and lightly protected vehicles. By simply exchanging the barrel and a limited set of internal components, the weapon can be converted to a 40 mm “Super 40” configuration, offering a growth path for additional lethality without redesigning the turret or vehicle architecture. Production for the ACV-30 is concentrated at Northrop Grumman’s facility in Mesa, Arizona, supporting both U.S. requirements and potential future export opportunities via commonality with other Mk44S-equipped platforms.
On the ACV-30, the Mk44S will be mounted in a Kongsberg remotely operated 30 mm turret, part of the PROTECTOR/MCT-30 family that has already been selected as the Marine Corps’ lethality solution for the program. This configuration keeps the crew under armor while allowing hunter-killer target engagement with stabilized day/night sights and integrated fire control. According to Kongsberg and BAE Systems, the turret has been marinized to withstand prolonged operations in the surf zone and open sea, integrating with the ACV hull, which is designed to operate from ship to shore in elevated sea states. Live-fire trials at events such as the Bushmaster Users Conference have already demonstrated the ACV’s ability to employ a 30–40 mm Bushmaster cannon effectively, validating the interface between the gun, turret and amphibious chassis. For the Marines, standardized use of the Mk44S across ACV-30 and other platforms simplifies logistics and training while enabling a common family of programmable ammunition tailored to coastal, urban and maritime environments.
Beyond the technical upgrade, the decision to move into full-rate production aligns closely with the Marine Corps’ Force Design restructuring, which emphasizes smaller, more mobile units dispersed across archipelagos and littorals, supported by sensors and precision fires rather than heavy armored formations. In this construct, the ACV-30 with a Mk44S-armed remote turret becomes a key node for direct fire support, defending expeditionary advanced bases and sea lines of communication against small surface threats, unmanned systems and light armored vehicles. The 30 mm cannon offers significantly greater range and terminal effect than legacy .50 caliber and 40 mm grenade launchers, giving Marine units a credible means to challenge fast inshore attack craft or hostile security forces attempting to deny access to contested beaches, ports or river mouths. The growth potential to 40 mm further improves the vehicle’s ability to defeat reinforced positions or heavier craft without resorting to higher-end missiles that are more expensive and limited in number.
These capabilities take on particular significance as U.S.–Venezuela tensions escalate, with Washington increasing its military footprint in the southern Caribbean under operations officially framed around counter-narcotics but widely interpreted as exerting pressure on the Maduro government. Trinidad and Tobago’s recent decision to grant U.S. military aircraft broader access to its airports, coupled with the installation of a U.S. radar and the seizure of a large Venezuelan oil tanker off the country’s coast, has sharpened Caracas’s accusations that neighboring states are facilitating a potential American intervention. In this context, Marine amphibious ready groups equipped with ACV-30s form part of a layered toolkit that can conduct non-combatant evacuation operations, protect maritime infrastructure, escort shipping, or, in a more extreme scenario, support limited raids or demonstrations near Venezuelan territory. While the number of ACV-30s fielded remains modest compared to the overall U.S. force posture, their enhanced medium-caliber firepower from ship-to-shore adds credibility to U.S. signaling and provides commanders with a scalable option between mere presence and the use of high-end air or missile strikes.
The shift to full-rate Mk44S production for the ACV-30 quietly but clearly strengthens the Marine Corps’ ability to project measured, credible force from the sea at a time when crisis scenarios in the Caribbean are no longer hypothetical. By marrying a mature chain-gun architecture with a modern remote turret on a new-generation amphibious chassis, Northrop Grumman and its partners are delivering a capability that fits squarely within the Marines’ transformation toward agile, distributed operations in contested littorals. The technical details of the Mk44S, from its programmable ammunition to its growth path to 40 mm, matter not only for the tactical overmatch they offer Marines in close combat, but also for the broader strategic message they send: U.S. amphibious forces are being re-equipped to operate, deter and, if necessary, fight along the very coastlines where political and military tensions with Venezuela are now most acute.