U.S. Navy buys more 30mm guns to shoot down drones

The U.S. Navy has awarded British-owned MSI Defence Systems a $197 million contract for 30mm deck gun mounts and the electro-optical sights that aim them, the weapons the service is fitting to its warships to shoot down small drones and fast attack boats.

The firm-fixed-price contract, issued by Naval Surface Warfare Center Indian Head Division in Maryland, covers MK88 MOD4 gun mounts, MK48 MOD2 electro-optical sights, related hardware and spares. The Department of War did not say how many systems it buys. Deliveries are due to finish by January 2031.

Together with an operator console, the gun mount and sight make up the MK 38 MOD 4 gun weapon system, which replaces the 25 mm MK 38 MOD 3 on U.S. Navy ships. The U.S. Navy has said the older system fell short of its requirements for countering drones, and the new version adds a larger 30 mm MK44 Bushmaster II cannon, with an optional coaxial .50-caliber machine gun. The mount holds 400 rounds in two separate ammunition bins, letting the crew switch between ammunition types.

Unlike earlier versions, the MOD 4 places its camera sight away from the gun rather than on the mount itself, so the system can track a target independently and pass aiming data to the gun. The design is based on MSI’s Seahawk DS30M A2 mount, a family of guns already used by the Royal Navy and other fleets.

The destroyer USS Mustin (DDG 89) became the first U.S. Navy warship to receive the system, with two mounts installed during a maintenance period in San Diego, Naval News reported in April 2024. The U.S. Navy plans to replace the 25 mm guns on its Arleigh Burke-class destroyers with the new system, and the U.S. Coast Guard also uses it.

The new contract is far larger than earlier orders. MSI received about $23.5 million in September 2023 for 15 gun mounts in low-rate production and about $34.5 million in late 2025 for 18 more, along with separate deals for the sight system. The company first delivered eight prototype systems for testing.

The U.S. Navy awarded the contract without competition under a legal exception for production that follows prototypes successfully completed under an other transaction agreement, a faster contracting route used for experimental work.

Most of the work, 73%, will take place at MSI’s facilities in Norfolk, England, with 19% at its U.S. subsidiary in Rock Hill, South Carolina, and the rest in Bozeman, Montana, and Eagleville, Pennsylvania. MSI Defence Systems is part of British company MS International.

The U.S. Navy obligated about $61.3 million at the time of award, drawing on weapons procurement and shipbuilding funds from fiscal 2023 through 2026, including money from accounts used to build new ships.