I woundn't use the caliber. That said I was a witness to a shooting by a cop. Back in the mid 60s. guy attacked the cop with a full sized crowbar. cop lurched back and fired with his issued S&W 38spec (158 RNL ammo). Hit the guy in the forehead. Hit the ground like a sack of potatoes. By the time the ambulance and all the other cops got there.. The guy sat up moaning and holding his head. I didn't know about zombies at the time but I thought he coulda been Dracula or something. Bullet traveled under the skin around the skull and stopped at about his hairline. He was a lucky guy..but still ended up in prison