Direct proof of use
U.S. Army M109A6 Paladin self-propelled howitzers were documented firing in Iraq during Operation Iraqi Freedom. DVIDS recorded a Camp Taji Paladin battery from 1st Battalion, 82nd Field Artillery Regiment firing in 2007 and reported that the battery had fired more than 3,500 rounds in support of combat operations during the 2006-2008 rotation.
DVIDS also documented Howitzer Battery, 3rd Armored Cavalry Regiment operating M109A6 Paladins at Badoush Prison outside Mosul in March 2008. The unit used the Paladins to support ground troop movement in the Mosul area and fired mostly illumination missions from the combat outpost.
Sources: General Fires Big Gun, Redleg Soldiers Conduct Fire Missions in Iraq, Badoush Paladin Fire Mission
Timeline
On July 31, 2007, a DVIDS image caption from Camp Taji described an M109A6 Paladin howitzer being prepared for firing and tied the weapon to the 1st Battalion, 82nd Field Artillery Regiment Paladin battery. The caption stated that the battery had already fired more than 3,500 rounds in support of combat operations in Operation Iraqi Freedom rotation 06-08.
On March 29, 2008, DVIDS imagery from Badoush Prison outside Mosul showed an M109A6 Paladin firing 155 mm illumination rounds in support of ground forces. A companion DVIDS report published on April 5, 2008 identified the unit as Howitzer Battery, 3rd Armored Cavalry Regiment and described average nightly fire missions from the site.
Sources: General Fires Big Gun, Badoush Paladin Fire Mission, Redleg Soldiers Conduct Fire Missions in Iraq
Narrative
The documented M109 use in this conflict was U.S. Army fire support. At Badoush Prison, the Paladins were positioned to support ground troop movement around Mosul and were described as mostly firing illumination rounds, while the unit also identified high explosive and guided rounds as available support options for troops in contact.
The available direct sources separate deployment from use: they do not merely list M109A6 Paladins as present in Iraq, but document specific batteries firing or preparing to fire during Operation Iraqi Freedom. The strongest records identify the user as U.S. Army field artillery units, the locations as Camp Taji and Badoush Prison outside Mosul, and the supported mission as combat or ground-force support.
Sources: Redleg Soldiers Conduct Fire Missions in Iraq, General Fires Big Gun, Badoush Paladin Fire Mission, Badoush Paladin Positioning