Ps - I use the same target every year. My rule of thumb more than 8 pellet holes in the neck vertebrae, skull only determines my lethal range.

I sight in the gun holding at the base of that picture and that is where the feathers stop and skin starts. that is the very bottom center of my circular pattern.
Does a couple of things you might want to consider;
1. I see the head the whole time I am holding on the bird. I am holding on the base of the neck.
2. Puts the dead center of my circular pattern in the middle of the neck.
3. Once I shoot the my pattern Allows me to cover the whole head.
4. Gives me a consistent area to target on the bird every and each time I have it in range.

After all with our tight patterns with these high speed loads to me it is just like we are shooting a slug. Aim at the whole bird you will miss it -Aik at one tiny little consistent spot helps you focus.

By using this method I have yet to miss a bird. Not saying someday I won't but since I became deadly serious as to why I missed before and did some research - I find it unlikley it will ever happen again.

JW