The only civilian I know who has shot and killed an assailant used a .45 '17 S&W with reversed HBWCs.

He was the proprietor of a gun shop/gun smith operation. A guy out on parole came into the shop and started asking questions about guns, calibres and ammo.
My buddy accommodated him, making the mistake of leaving a 1911 and a loaded magazine on the counter while he looked for something else the guy wanted to see. The creep robbed him at gun point with the 1911!

My buddy didn't resist, as his wife was in the apartment on the 2nd floor. After using duct tape to immobilize his hands, the guy took the cash from the register and kicked him in the head as a parting gift after putting the cash, a couple of guns and ammo into a box.

This enraged my buddy to the point where he broke the tape, grabbed the '17 and went after the creep. The creep's girl friend was in the car with the doors locked!
The creep put the box on the roof of the car and fumbled in his pocket for the keys. My buddy put the drop on him, ordering him to surrender, but the creep fired at him, hitting with him two body hits of FMJ .45 ACP ammo.

Before he fell, he fired several times at the creep with the '17, hitting him fatally. He then turned and fell into the arms of his wife gouting blood. It took several operations and psych counselling to get him well.

The Point - reversed HBWCs did the job very well.

I suspect that reversed .38 Spl. HBWCs would have done the job just as well. I've tried them in my 4" M66 on water filled milk jugs and it was impressive.