Marines Poised To Get Their 30mm Cannon-Armed Amphibious Combat Vehicle

Armed with a 30mm Bushmaster cannon, the ACV-30 will provide the U.S. Marine Corps with its largest direct-fire gun.

byThomas Newdick|
The Marines' ACV is getting a big 30mm cannon.
One of the production-representative test vehicles (PRTVs) for the ACV-30 program. BAE Systems


The U.S. Marine Corps has laid out plans to introduce the ACV-30, the version of its new Amphibious Combat Vehicle armed with a 30mm cannon. As TWZ has explored in the past, the ACV-30 reflects broader trends within the U.S. military to up-gun existing and future armored vehicles, something that has only become more relevant in light of battlefield lessons from Ukraine.

Speaking at the Modern Day Marine exhibition, which TWZ has been attending, Tim Hough, Commanding Officer and Program Manager Advanced Amphibious Assault (PM AAA) at the U.S. Marine Corps explained that the ACV-30 is now in developmental test, with three production-representative test vehicles (PRTVs) having been received at the end of January this year from manufacturer BAE Systems.

One of the production-representative test vehicles (PRTVs) for the ACV-30 program. BAE Systems BAE Systems

The current program of developmental testing is planned to lead to operational test in the second quarter of FY 2025 before the ACV-30 enters production. Hough said he was confident of production starting also in FY 2025, followed by delivery of the first six series-manufactured vehicles in FY 2026.

This initial batch of ACV-30s will be put through their paces to achieve a declaration of initial operational capability (IOC), expected in the third quarter of FY 2026. The benchmark for this milestone is six vehicles integrated into an ACV-equipped amphibious assault line platoon.

“This is the one that gets all the love,” Hough observed, in his discussion of the four different mission-role variants of the ACV. “It’s got the biggest cannon, and everybody seems to gravitate toward it.”

The mission-role variants comprise the baseline version of the ACV, the ACV-P personnel carrier, with a crew of three and up to 13 Marines; the ACV-C command and control variant; and the ACV-R recovery variant.

Marines from the Amphibious Combat Vehicle New Equipment Training Team (NETT) complete an operator course in the vehicle. U.S. Marine Corps photo by Ashley Calingo

In fact, the ACV-30’s Mk 44 Stretch Bushmaster dual-fed cannon will be the largest direct-fire gun in the Marine Corps' inventory, following the service’s divestiture of its M1 Abrams tanks. The USMC does have other 30mm guns, such as those on the Marine Air Defense Integrated System (MADIS) vehicles, but these are smaller, less powerful weapons based on the gun used in the AH-64 Apache. Previous plans to field a 30mm cannon on the Expeditionary Fighting Vehicle (EFV) came to an end when that program was canceled.

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“What I will tell you is this is a critical, critical capability for the Marine Corps,” Hough continued. “It is the largest weapon system that supports infantry maneuver on the battlefield,” following the reconfiguring of the Marines under the Force Design initiative, which also saw it give up its tanks.

“It is a critical capability to enable the infantry commander to do what he needs to do and destroy and defeat light adversary combat platforms,” Hough added. On the ACV-30, the Mk 44 cannon is allied with sighting systems that can detect targets “well out beyond five kilometers” — 3.1 miles. These kinds of ranges are “well beyond what we’re seeing now” with the ACV-P that has a remote weapon station armed with an M2 Browning .50-caliber machine gun heavy machine gun or a 40mm grenade launcher.

As we reported at the time, Marine Corps Systems Command confirmed plans for the ACV-30 in January 2019.

This was a little more than six months after the Marines announced the selection of the SuperAV 8x8 wheeled armored vehicle as the winner of what it had called the ACV 1.1 competition. The successful proposal was offered by BAE Systems together with Italy’s Iveco. Soon after, the Corps said it would look to begin a follow-on “lethality upgrade” for the vehicles, then known as ACV 1.2.

In May 2020, Norway’s Kongsberg Defense & Aerospace revealed that it had been selected by BAE Systems to design and manufacture the remote Medium Caliber Turret (MCT) for the ACV-30.

An ACV-30 with the Medium Caliber Turret (MCT) fitted. Kongsberg

The 30mm version of this turret, the MCT-30, had previously been adopted by the U.S. Army for its Stryker Brigade in Europe, and has been fielded on this service’s Infantry Carrier Vehicle — Dragoon (ICV-D) variant since 2018.

The turret is remotely controlled and operated from a protected position inside the vehicle compartment. The Mk 44 cannon is fed with linkless ammunition.

A U.S. Army Infantry Carrier Vehicle — Dragoon (ICV-D), also armed with the Mk 44 cannon. U.S. Army Operational Test Command Public Affairs

As we noted when plans to up-gun the ACV were first announced, the Marines are only adding the 30mm turret to the ACV-30 version, leaving the ACV-P with its standard armament of a single .50-caliber machine gun or 40mm grenade launcher in the remote weapon station turret.

Current plans foresee the Marines receiving a total of 175 ACV-30s, which will be operated alongside 390 ACV-Ps, 34 ACV-Rs, and 33 ACV-Cs. As it stands, deliveries to the Marines comprise 187 vehicles: 138 ACV-Ps and two ACV-Cs to the 3rd Assault Amphibian Battalion, and 46 ACV-Ps and one ACV-C to the Assault Amphibian School. Both these units are at Marine Corps Base Camp Pendleton, California.

The basic ACV-P is actually less heavily armed that its predecessor, the tracked Assault Amphibious Vehicle (AAV). Standard armament for these older vehicles is a manned turret with both the .50-caliber machine gun and 40mm automatic grenade launcher.

A prototype ACV. Public Domain

With that in mind, the forthcoming arrival of the ACV-30 will provide a much-needed boost in firepower for the Marines’ amphibious battalions.

Overall, Col. Hough painted an optimistic picture of the ongoing introduction of the ACV family, which he described as a “21st-century digital wheeled platform” that will provide a full replacement for the AAV — which he likened to an “analog, armored Winnebago.”

“We have bled every bit of blood out of that stone,” Hough added. “It’s over 50 years old.”

An AAV during a Marine Corps Combat Readiness Evaluation at Marine Corps Base Camp Pendleton, California, in March 2014. U.S. Marine Corps photo by Lance Cpl. David Silvano/released

As this process continues, another milestone just around the corner will be the fielding of the first ACV-Ps in Okinawa, Japan, bringing much-needed modernization to the Pacific theater. Here, the Marines are rapidly preparing for a potentially huge conflict with China in which amphibious capabilities will be at the forefront.

This July, 12 ACV-Ps will arrive with the 4th Marine Regiment, III Marine Expeditionary Force, based at Camp Schwab in Okinawa.

When the SuperAV 8x8 was selected as the basis of the ACV it was noted, including by TWZ, that the new vehicle would not be able to swim any faster in the water than the veteran AAV.

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Hough noted that fact, too, but pointed out the many other benefits he sees in the ACV series compared to its predecessor, spelled out simply as shoot, move, communicate, and protect.

In terms of firepower, the basic ACV-P has the same Kongsberg remote weapon station as found on the AAV, making it a relatively straightforward process for gunners to transition to the new type.

Mobility-wise, Hough rates the ACV as similar to the AAV, apart from being slower in the water. Its ability to operate in conditions of high surf — up to six feet in certain scenarios — is equivalent to the AAV. “But where it really shines is on land,” Hough explained, noting that 85 percent of its operational mission profile is on terra firma, not in the water.

Once on land, “it has a far better range than the AAV and can operate about 20 miles an hour faster [than an AAV can].”

Communications among the crew and the squad of troops in the back of the ACV are an order of magnitude easier than in the AAV, Hough says. “They can have a conversation without having to scream, which also increases their survivability. They also have a screen in the back so they can see what’s going on around the vehicle.”

Finally, for the critical issue of protection, the ACV also brings key advantages, Hough says.

“What I will say, from someone who was a company commander in Iraq in 2007, I lost five AAVs to improvised explosive devices. This vehicle [the ACV] is purpose-built to withstand a blast far exceeding what an AAV can withstand. So from that perspective, this vehicle is far more capable than what we witnessed in our legacy platform.”

A Marine Corps AAV destroyed near Nasiriyah, Iraq, in March 2003. U.S. Department of Defense

As well as being better protected from the dangers of the battlefield, the crew in the ACV can also ride into battle in a little more comfort.

“In the AAV, if you hit the brakes pretty hard, you can always shove another Marine in the back. [The ACV] is purpose-built in that every Marine has his or her seat with a five-point harness, and that ties back to the survivability requirement that we have for this vehicle.”

After all, as Houth puts it, “This is God’s chariot and only his angels get to drive it.”

With the up-armed ACV-30 now waiting in the wings, the Marines’ latest amphibious assault vehicle is going to offer valuable additional firepower to those soldiers, something that is especially important as the service continues to recalibrate, moving away from counterinsurgency campaigns to the high-end fight of the future.

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