Formerly known as the M1, the M114 was a 155mm-caliber field howitzer used by the US Army and Marine Corps in every theater of operations of World War II, and also during the Korean and Vietnam Wars, entering service in 1942. This truck-towed 6-ton howitzer could be transported by aircraft and cargo helicopters. With a barrel length of 12 ft 5 in (3.8m), the M114 had a maximum range of 14.6 km, shooting separate loading, 6.30kg ammunition (M3, M4, M4A1). It had a rate of fire of 4 rpm and a muzzle velocity of 563 m/s. This American howitzer had a hydropneumatic recoil system and was mounted on a two-wheeled, split-trail carriage. Elevation ranged from -2º to +63º; traverse: 25º right/left. To get it ready to fire, the weapon was stabilized by a 3-point suspension, two of which are the welded steel trails spread a wide angle; the third point was provided by the firing jack on the carriage.