PC what exactly is a critical hit and is it working in A17?

[danielspoa]

So, while working on items I noticed the sledgehammer has a crit chance property that's unique to him. Looked around the internet and so far didn't find exactly what this critical blow would cause, much less if it's working in A17. I found that sledgehammer could cause stun and dismember a zombie, not sure if one of these effects is linked to the critical chance or if there's extra damage (and how much).

Does anyone know the exact effects?

 

[thedu]

im pretty sure critical hits are limited to popping off heads and limbs, and i know you only get head explosions at lvl 3+ of cracking skulls. so it doesnt do any extra damage, the bonus is either instakill or disable.