a metal block in breech-loading firearms that is withdrawn to insert a cartridge and replaced to close the breech before firing
同义词：breech closer
breechblock详细解释
breech.block n.（名词）The metal part that closes the breech end of the barrel of a breechloading gun and that is removed to insert a cartridge and replaced before firing.炮闩，枪闩：关闭后膛装弹枪的枪后部的后膛的金属部分，可以拆卸下来装子弹并在射击前被替换
