Japan Orders Mk19 Grenade Launchers from U.S. for New Patria AMV APCs

Japan has ordered 40 mm Mk19 automatic grenade launchers from the United States to equip its new Patria AMV wheeled armored personnel carriers.

This was reported by the official website of the Acquisition, Technology and Logistics Agency (ATLA) of Japan’s Ministry of Defense.

The total value of the deal is JPY 934,703,000 (approximately $6 million) for 72 grenade launchers.

The supplier is Sumisho Aero-Systems Corporation, based in Tokyo.

The document states that the company is the sole official importer and sales representative of U.S. Ordnance in Japan.

Japan already operates 40 mm automatic grenade launchers, including the Howa Type 96.

However, this system is no longer in production and is mainly mounted on Type 96 armored personnel carriers, as well as used in portable infantry versions.

The main reason for adopting the U.S.-made Mk19 for new armored vehicles is ammunition compatibility. The Howa Type 96 uses a proprietary 40×56 mm round developed by Daikin Industries.

This ammunition is not compatible with standard NATO 40×53 mm grenades used by the Mk19.

Japan also operates Mk19 grenade launchers on its AAV7A1 amphibious armored personnel carriers in service with the Amphibious Rapid Deployment Brigade.

Earlier, Militarnyi reported that in November 2025, the Japan Ground Self-Defense Forces equipped the first unit with new Patria AMV XP armored personnel carriers, which entered service with the 3rd Rapid Deployment Regiment.

In total, the Japan Ground Self-Defense Forces plan to acquire 810 vehicles of this type, to be manufactured by Japan Steel Works on the island of Hokkaido. More than half will be produced in the armored personnel carrier variant, with the remainder configured as command and staff vehicles, radiation, chemical and biological protection (RCB) vehicles, and medical evacuation vehicles.