M50 Ontos - Service

Service

While the M50 was designed as a tank destroyer, the NVA deployed few such targets. It was more widely used for direct fire support for the infantry in combat, a role that was never emphasized in training or doctrine. Like the Army's M113, its light armor was effective against small arms but vulnerable to mines and RPGs. Consequently many Ontos were deployed in static defense positions.

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. The Ontos, with its lower ground pressure, could drag timbers up to the tanks to help get them unstuck. In another operation, the Ontos was the only tracked vehicle light enough to cross a pontoon bridge. 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, which suffered heavy losses, while at ranges of 300 to 500 yards (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. In Operation De Soto, the introduction of the large CH-53 Sea Stallion helicopter made possible moving a platoon 25 miles (40 km) south of Quan Ngai City carrying Ontos in slings underneath the aircraft.

The Ontos units were deactivated in May 1969, and some of the vehicles were handed over to an Army Light Infantry Brigade. They used them until they ran out of spare parts, and then removed the turrets and used them as fixed fortifications. Both these and the rest of the vehicles returned from Vietnam in 1970 and were cut up for scrap, with some of the chassis being sold off as construction vehicles.