Direct proof of use
155 mm NATO-standard ammunition is documented in the anti-ISIS campaign through coalition artillery fire missions in Iraq. U.S. Army reporting from Firebase Saham said a U.S. M777A2 crew fired volleys of 155 mm high-explosive shells while the firebase supported efforts to stop ISIS fighters moving near the Iraq-Syria border.
A separate U.S. Army account of Operation Swift described a 155 mm artillery round leaving an M777A2 during a coalition gun raid in Iraq's Makhmour Mountains on December 22, 2018. The raid combined artillery with airstrikes against ISIS targets and was conducted in coordination with Iraqi Security Forces.
Sources: Firebase Saham: A Day in the Life of Joint-Artillerymen Securing the Iraq Border, Troopers Conduct Powerful Gun Raid Against ISIS
Firebase Saham and border fires
Firebase Saham was established near Iraq's border with Syria in November 2018. U.S., French, and Iraqi artillery elements operated there during the Middle Euphrates River Valley campaign, with U.S. M777 howitzers, French CAESAR 155 mm self-propelled howitzers, and Iraqi M109 Paladins providing coordinated fires.
The Army account ties the ammunition role to interdiction and fire support. The firebase's artillery mission was to prevent ISIS fighters from crossing into Iraq and to support partner operations across the border. DVIDS imagery from October 21, 2018 also documents Task Force Wagram conducting a fire mission from Firebase Saham in support of Operation Roundup.
Sources: Firebase Saham: A Day in the Life of Joint-Artillerymen Securing the Iraq Border, Firebase Saham Artillery Mission
Marine fire support in northern Iraq
DVIDS reporting on Battery E, Battalion Landing Team, 2nd Battalion, 6th Marine Regiment, records another 155 mm ammunition use case during Operation Inherent Resolve. The Marine battery operated from an austere firebase in northern Iraq, provided fire support to Kurdish Peshmerga Forces and Iraqi Security Forces, and fired 2,061 rounds of 155 mm ammunition during 476 fire missions.
The same report says the battery used four M777A2 howitzers and employed Precision Guidance Kit fuzes. For this NATO-standard ammunition page, the key documented point is combat use of the 155 mm ammunition family by coalition artillery in the anti-ISIS campaign; the source does not identify every projectile model fired.
Sources: Inspector-Instructor Awarded for Heroic Action and Leadership
Role in the conflict
The documented use was coalition and partner-force fire support rather than a stand-alone weapon deployment. In the available official reporting, 155 mm ammunition appears through M777A2, CAESAR, and M109 artillery units supporting Iraqi and Syrian partner operations, interdicting ISIS movement, and striking weapons caches, hiding places, and border-crossing routes.
The sources support use in Iraq during Operation Inherent Resolve within the broader 2014 War Against the Islamic State. They do not support a complete theater-wide ammunition inventory, exact round types for every mission, or a claim that every 155 mm shot fired in the campaign used the same projectile variant.
Sources: Troopers Conduct Powerful Gun Raid Against ISIS, Firebase Saham: A Day in the Life of Joint-Artillerymen Securing the Iraq Border, Inspector-Instructor Awarded for Heroic Action and Leadership
