the U.S. Army in 1951, replacing the previous M2 106.7 mm mortar. It was adopted due to the extended range and lethality in comparison to the previous M2 mortar, although the M30, at , was significantly heavier than the M2. Due to this heavy weight, the mortar was most often mounted in a tracked mortar carrier of the M113 family, designated as the M106 mortar carrier. This vehicle mounted mortar was crewed by five people: the track commander (mortar sergeant/gun commander), gunner, assistant gunner, ammunition bearer and vehicle driver. Ground mounting of the mortar was time consuming and strenuous as a hole had to be dug for the base plate of the mortar to rest in, sandbags had to filled and placed around the base plate to stabilize it and to protect the exposed ammunition. Also, this decreased the accuracy of the weapon as the recoil from firing caused the base plate to shift in the ground. This movement also made the crew have to "lay" the gun back on the aiming stakes more often, causing a temporary lack of fire while the weapon was repositioned and re-sighted back to its original reference point. During the Vietnam War, both the US Marine Corps and the US Army deployed the M30 mortar. The USMC mounted the M30 mortar on the carriage of the M116 howitzer, this assembly being known as the M98 Howtar. The Saudi Arabian Army deployed the M30 in 1990-1991 during the Gulf War. The M30 was also used in Bosnia during Operation Joint Endeavor in 1996. Users : less than 20 : 4 : 620 (including 231 on vehicles) in service in the Hellenic Army : 12 from Israel, in store : 50 : 6 : 20 : 40 in the Philippine Army and some in the Philippine Marine Corps : 30 (including 20 on vehicles) in service : ~150 in service with the Saudi Arabian Army , some used on vehicles : 1,264 : US Army and US National Guard References See also List of artillery List of crew served weapons of the US Armed Forces Chemical mortar battalions of the United States Army Weapons of the Laotian Civil War Weapons of the Lebanese Civil War External links Chapter 6, FM 23-90: 4.2-Inch Mortar, M30 Infantry mortars Mortars of the United States 107 mm artillery Chemical weapon delivery systems Military equipment introduced in the 1950s