blunderbuss

例句：

1. 1.The policeman used a blunderbuss to frighten away the thieves.
   警察用大口径步枪吓跑了小偷。
2. 2. He carried a big-barrel shotgun for protection.
   他带着一把大口径霰弹枪以防身。
3. 3.The old man was using his big-bore gun to defend himself against the attackers.
   老人用他那笨重的火器来抵御攻击者。