How did the U.S. Army's M-1952 armoured vest protect soldiers during the Korean and Vietnam wars?

The M-1952 armoured vest was introduced by the U.S. Army during the latter stages of the Korean War to provide soldiers with enhanced protection.1

The vest weighed 8 pounds (3.6 kg) and utilized 12 layers of flexible, laminated nylon to offer ballistic protection specifically against shell fragments. U.S. soldiers and marines continued to utilize this design throughout the Vietnam War. It remained in service until it was eventually replaced by the M-1969 fragmentation protective body armour, which maintained the same core protective characteristics while incorporating minor improvements.1