The Ontos, officially the Rifle, Multiple 106 mm, Self-propelled, M50, was an American light armored tracked anti-tank vehicle developed in the 1950s
About this creation
Originally conceived as a fast tank killer, it was employed by US Marines who consistently reported excellent results when used for direct fire support against infantry during the Vietnam War. Its mobility and firepower were proven in numerous battles and operations. Produced in limited numbers and largely expended towards the end of the conflict, the Ontos was removed from service in 1969.
The Ontos mounted six M40 106 mm recoilless rifles as its main armament, which could be fired in rapid succession against single targets to guarantee a kill.
The Ontos was based on the running gear of the M56 Scorpion light anti-tank vehicle. The vehicle mounted a cast steel turret with two arms holding three rifles each. This early models could traverse the turret only about 15 degrees. A second prototype used a new suspension system including new tracks, and a newer turret with about 40 degrees traverse. Only eighteen rounds for the main guns could be carried inside the vehicle due to limited space.
The Ontos was particularly liked by its crews, and praised by commanders. Their relatively light weight meant that the M50s could also go where tanks got bogged down. In the Battle of Hue, Regimental commander Colonel Stanley felt the Ontos was the most effective of all Marine supporting arms. Its mobility made it less vulnerable than tanks, while at ranges of 270 to 460 m, its recoilless rifles could knock holes in or completely knock down walls. The appearance of an Ontos was sometimes enough to make the enemy break and run.