On that basis, the vertical lapse stack source, energy concentrated bullet and explosive seismic hammer source have been developed.

在此基础上，研制了垂直延迟叠加震源、聚能弹震源和爆炸地震锤震源。

youdao

Grenade launchers, mortars and conventional artillery are cheaper, but more likely than a single explosive bullet to cause collateral damage.

ECONOMIST: Military technology