Headshots on little vermin work great with a pellet rifle most of the time. If they don't, it's no big deal. The size and shape of their head make it an easy target and the way they freeze to look at you from cover it's often your only shot. Their facial bones are delicate and easy to penetrate and their size and weight make a headshot ideal.
A lot of guys get good at this shot and assume they can apply this technique to other animals. They may have some success a time or three and think it's a reliable and ethical kill.
It's not.
If you shoot 100 head shots at deer, elk, coyotes, bobcat etc. 15-20 will be failures. Even with a firearm. The head is elongated and the brain is MUCH farther back in the skull than most guys think it is. (It's more at the top of the neck than in the "head").
Most "head shots" are sinus and facial shots. With a firearm it might give them a severe concussion or render them blind. Many "headshot" deer are not dead but simply stunned or paralyzed. Some wake up while your taking photos and kick your ass or run off blinded.
The brain on (most) animals (besides humans and other round headed vermin) are at the very back of the skull behind the ears and horns. Looking broadside a deer, elk or antelopes brain is at the top of the neck behind the horns. A shot in the ear canal is the very front edge of the brain. Forward of the ear canal it's a sinus shot.
You couldn't hit the brain from a frontal shot with a 22-250. It may kill with a concussion but it's not going to penetrate into the brain. A broadside or leaving shot is the ONLY brain shot on these animals. BEHIND the horns. BEHIND the ears. At the very top of the neck as it rolls over to form the crown.
Air gun hunters always speak about "head shots" and "precise shot placement". They fantasize about instant kills on larger animals. Some have even had some success. I can assure you that they will have some extreme failures if they are relying on headshots to harvest game.
Some hunters (very few) know the physiology of the animal and can make an effective headshot with a rifle. Most have no clue where the brain sits and shoot too far forward. That is a recipe for disaster unless your shooting a high powered rifle. Even then it's a craps shoot if the shot isn't BEHIND THE HORNS where the neck curves into the head.
Look where the brain cavity is. Behind the horns, behind the ear. Behind the crest of the skull at the very back. It's more upper neck than head when you are looking at the animal in the field.
A leaving shot from the rear below the horns is the best shot. You can clearly see how most "head shots" don't even come close to the brain. The brain is in the upper neck. Not the head.
A frontal brain shot is almost impossible. You must penetrate the thickest bone at a steep angle. It just dosent work. The brain is 6" behind the toughest part of the skull. Even a .243 won't reach it. The bullet will deflect and go out the side. A concussion or broken neck is the best you could hope for. Even a big airgun won't do it. A .44 mag probably wouldn't. There is just too much bone and mass in front of it.
Chronic wasting disease is a problem everywhere. Hunters are advised to not damage the skull or the spine. The disease resides in the synovial fluid. The biologists are explicit and ask that hunters not take headshots as it has the potential to spread the disease. Another good reason to shoot an animal in the appropriate spot.
...above the diaphragm along or in front of the line of the legs (when broadside on level ground) using a rifle capable of breaking the shoulder bones and stopping no sooner than the hide on the far side.
