The constant search for a more effective infantry weapon led in the 1990s to the concept of small - calibre high - explosive fragmentation grenade shells designed to burst over the heads of their targets , thereby permitting the attack of troops in defilade , ie hiding behind cover 源于上世纪八十年代的对更加有效的步兵武器的不断研究得出了小口径高爆破片手榴弹的外壳设计用于杀伤目标头部的概念,从而形成了对隐藏于工事及掩体的部队进行攻击的手段。