I shot a spike bull over 50 years ago, using my Dad's 270 Win with a 2 3/4x Stith Bearcub with a 3min Lee dot. The bull was looking at me from about 20 yards away, he was standing behind some regen firs, all I could see was his left eye, left antler and the tip of his nose. Put that Lee dot on his eye and shot, he didn't move, just kept looking at me. I took a step to my right and held on the top of the neck, down he went. Because it was getting dark and with a head shot the nervous system is going through major disconnect issues and all his legs were going like crazy, had to tie them off to trees one at a time so I wouldn't get kicked to death. Think a chicken with his head cut off.
Many years later, I was hunting with my Ruger Super Redhawk 44 mag. About day 5 or 6 of elk season. Ran across blood in the snow, kind of sprayed each side of the tracks. The tracks were splayed out like the animal was spooked, but normal stride, so not spooked. Tracked that elk for well over 1/2 mile down a draw, many trails led out of the draw but were uphill, this elk kept just going down. There was a branched antler hunt and a cow hunt going on, but I only had a spike only general tag, didn't know what I was going to find at the end of the tracks. Came around a corner in the draw and there was a spike bull with his lower jaw hanging, killed him with my 44 mag. He was so dehydrated that he would have died right where I got him, logs across the draw like a gate. Turns out he was shot about 4 days prior.
Long story short, I don't take head shots any longer.