Its not as easy as it looks, and forget what you see in the movies! There are many reasons why its necessary to practice this a lot.
Let me count the ways:
1. Hitting the head is not enough, you need to destroy the BRAIN. The living dead will not be hindered with shots going to any other location. And this makes it even harder because only the upper half is a valid target!
We also need a caliber that will get the job done with the least amount of bullets...
2. Now try that against a moving target. A zombie's lurch will be uneven because of the stiffness of their joints. They do not walk like regular folks so their heads will move in all sorts of jagged movements. Trying to get good groupings on a stationary target is tough, but this ain't no ordinary target. This brings us to point number three.
3. The zombie will be moving towards YOU. And don't assume that they will be slow. Even a brisk walker can close a short distance to grab & eat your brains. Its easy to freeze like a deer facing oncoming traffic. When the living dead are headed your way, you'll lose more than your wits for sure.
4. The living dead are frightening. Looking at a regular corpse will unsettle any of us. (pay attention to those who aren't affected!) What more if its the sort of corpse that is walking... moving... and making a spine tingling moan as it shuffles to devour you. I mean, corpses aren't suppose to move! It will drive you insane just seeing it before your eyes! What more if there's a horde of them doin' the THRILLER in your direction?
still gives me the creeps dammit
All these proves that nobody is prepared to destroy a zombie with traditional training or psychology. This is a new enemy that we must carefully prepare for. Be prepared to see professionals lose their cool. Be prepared so you don't!
The biggest mistake that some fellow survivalists, gun nuts, & internet tough guys will make is to assume that their monstrous armory of fancy guns will save them. I strongly disagree.
We must strive to prepare to face an unearthly and deeply unsettling foe. With constant practice we can attempt to overcome our fearful instincts with drills and muscle memory.
Thats my tiny stockroom behind the door.
And I am ABSOLUTELY certain that nobody is behind it. Safety first!