I have shot a few in the head as they stood behind a bush with only their head visible for me to shoot at. They were looking straight at me, and it was either take the shot or they were going to disappear.
They are usually at some yardage when they do this.
Several head shots I remember. One was with a 22/250 AI with the 50g Nosler ballistic tip at a muzzle velocity of 4200. I had ranged a group of p. dogs when the coyote's head stuck up over a bush.
I had already dialed in the yardage. I hit him just above the eye, and the bullet did not exit the back of the skull....go figure. I have a picture some where of the the head shot.
I used a 6mm Remington Parker Hale Varmint for 4-5 years, put a 26" Shilen bull barrel on it in a 12T with zero freebore. I shot the 60g Sierra and Bergers at 4000 fps. Several coyotes stopped looking at us Usually from 200-300 yards, and all you could see was the top of the jaw line up. One on of the shots in particular the hit on the coyote was square between the eyes, and his eyes flew out in a V shape straight up. On the second coyote, I hit him square in the nose, and the top of his entire head flew off.
I wish that I had never got rid of that parker hale as the roll over cheek piece fit like nothing else since.
Shooting through a bush with a coyote's body behind the bush is a hail mary shot. I have tried it with all calibers. Those small twigs and branches deflect bullets dramatically.
To start out intentionally wanting to shoot coyotes in the heads, is fools play.