.22 vs Skulls.... I mean Coconuts

With all the country obsessed with zombies, I thought I'd try an experiment.
Several people have touted the .22LR as the perfect round for slow 'Romero' style zombies. I know, you don't know if you should laugh because of 'zombies' or that some people think a .22 can penetrate a skull at any real distance. But hey with "The Walking Dead" being a hit show, I've heard several people asking if the .22 could work.
And I rolled my eyes at the thought.
First off, the .22 is NOT a combat round. It is a training round, and a fun to shoot round. By NO measure a combat round.
Now back to my experiment.
Since I couldn't get anyone to volunteer to be shot in the head (Damn you all, It's for science!!), I had to look to alternatives. So standing in for a skull, I used coconuts. A doctor friend remembered reading that a coconut is slightly stronger than the strongest part of a human skull and was used to test helmets in the '30s (before moving on to animal testing).
The weapons, A Ruger Mark II.

And A Smith & Wesson M&P 15/22

For a visual comparison, here's a .45ACP next to a .22LR with a nickel thrown in for gauge


My plan was simple. I'd set 2 coconuts (one for the pistol and one for the rifle) at 100 yards, 50 yards, and at around 20 yards. I would start at the 50 yard range and work from there.
I expected these results. The pistol would be ineffective at 50 and 100 yards. And marginal at 20. The rifle would be ineffective at 100 yards, marginal at 50, and effective at 20. I expected this because the .22 is known for ricocheting off curved surfaces, and it is a low power cartridge.

Well here is the 50 yard pistol hit.

Above is the entrance. Below is the exit.

WOW. Not at all what I expected.
So I tried again at 100 yds (And tried and tried and tried, you try to hit a coconut at 100 yards with a .22 pistol without a bench rest)

It entered but did not exit. I did this multiple times (I have 1 coconut left out of 6).
Results? I have to up my opinion of the .22LR, It would work in a 'Walking Dead' scenerio. But, I still wouldn't bet my life on it if I had a better option.

Dan Emplit WBFD