155mm M109A1

The M109A1 is an American 155mm self-propelled howitzer, an upgraded variant of the original M109. It features a longer M185 cannon, which significantly improved its maximum firing range.

Developed in the late 1960s, this upgrade was initiated to counter the superior range of Soviet artillery systems during the Cold War. The system entered service with the United States Army in 1973, with many existing units being retrofitted to the new standard. It saw significant combat deployment with the Israeli Defense Forces during the 1973 Yom Kippur War and was later utilized by various export customers in conflicts such as the Iran-Iraq War. While the A1 variant has since been retired from active U.S. service, its design established the foundation for the long-running M109 family, including the modern M109A7 Paladin.