actually you dont need to hit the fish. the shockwave from the bullet hitting the water will kill them.
Maybe if they are IN the bucket but not if they are in the water. In fact sometimes even shooting the actual fish when breaching or jumping, unless in the head (and with hardheads even then,) sometimes won't kill it. It is all about placement. Folks kill gators and poach deer with .22, illegally but effective at close range and good placement.