U.S. Navy and Coast Guard Moving to Adopt Mark 44 30mm on MSI Mount

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Naval News reached out to Northrop Grumman in late March 2022 and received a reply addressing the functionality and weapon system’s installation of the 30mm autocannon on an MSI mount that will enter U.S. Navy, Coast Guard (USCG), and Marine Corps (USMC) service. The Mark 44 30mm autocannon on an automated MSI mount is named the Mark 38 Mod 4.

The Mark 44 30mm gun is already in service in enclosed Mark 46 Mod 2 turrets aboard the San Antonio-class amphibious transport docks (LPD), the Littoral Combat Ships’ (LSC) Anti-Surface Warfare Module (ASuW), and the stealthy Zumwalt-class destroyers (DDG 1000s). The MSI pedestal mount (named Mark 38 Mod 4) installs the Mark 44 30mm autocannon on those ships that do not have an enclosed turret as found aboard the LPDs, LCSs, and DDG 1000s to replace the Mark 38 25mm autocannons in the Mod 1, 2, and 3 versions.

Two 30mm Mark 46 Mod 2 turrets are fitted above the hangar of the three Zumwalt-class destroyers. The right turret is test-firing in this photo. These are not going to be replaced with Mark 38 Mod 4s (US Navy photo)

Mark 38 Mod 1, 2, and 3 25mm autocannons can be found on many U.S. Navy ships ranging from the Command ships, DDG 51s, Mark VI Patrol Boats, Sub Tenders, Patrol Coastals, LSDs, LHDs, and for the U.S. Coast Guard, the Fast Response Cutters (WPC), the Patrol Boats (WPB), The Reliance-class Medium Endurance Cutters (WMEC), and the upcoming Offshore Patrol Cutter (WMSM) and Polar Security Cutters.

“We expect between 20-30 MK44s to be delivered in 2023 to support the new Mod 4 turret. We will supply 115 in 2024 for the Marine Amphibious Combat Vehicle.”

William Gibbens, Northrop Grumman

In terms of lethality, range, and performance, the 30mm round obviously is an improvement over the 25mm round but one has to visually see the size difference here.

*A U.S. Marine Corps’ Amphibious Combat Vehicle with a Mark 44 30mm autocannon to be called ACV-30. The exact turret of the 30mm may differ from this photo.* Photo: US Marines

“The Mk44s will be the main weapon on the Mk38 Mod 4 turret (the MSI turret). There will also be another COAX gun on the mount, most likely an [.50cal] M2HB,” William Gibbens of Northrop Grumman, makers of the 30mm autocannon, said. The Mark 44 on MSI mount can also be fired manually. “There are handles attached to the rear or the Mk38 Mod 4 turret that can be used to fire the weapon manually as long as the turret has power which is why it has backup batteries. It is not designed to be fired manually, but it can be manually fired through [a] special weapon station, such as the Mod 4.”

Naval News asked Northrop Grumman on if the U.S. Coast Guard is adopting the Mark 44 with MSI turret aboard their Cutters. “Yes,” replied Gibbens, “The plan so far is that they will be adopting the Mk38 Mod4 turret with our Mk44s cannon.”

Naval News reached out to the U.S. Navy’s Naval Sea Systems Command (NAVSEA) and the U.S. Coast Guard’s Public Affairs for comment in early April 2022 on which U.S. Navy ships and Coast Guard Cutters are slated to receive the Mark 38 Mod 4 30mm autocannon on MSI mount. NAVSEA replied that all the information on the Mark 38 is posted on their website, but a review showed no mention of the Mod 4 30mm on an MSI turret. The U.S. Coast Guard did not immediately reply to Naval News’s inquiry.

Naval News also contacted MSI, makers of the Mod 4 mount, for comment in early April 2022 and received an immediate reply. According to MSI, the name of the system in U.S. Navy service is indeed called the Mark 38 Mod 4 (not the MSI-DS “Seahawk DS30M R” as advertised in Europe) and the Mark 38 Mod 4 has the following characteristics: