13 days ago - Shurenai - Direct link
Hitboxes work fine for me; And for most people.

So there's something on your end that's gone awry here..Unfortunately, I couldn't say exactly what with no information on your pc and no logs. :(

The most common reason I've seen, though, is insufficient performance in the PC; If the computer can't keep up with the game, the animations and where the game thinks the zombies are and what position it thinks they're in can desync, leading to the effect you're referring to.
13 days ago - SylenThunder - Direct link
There is also the glancing blows system that a lot of people don't understand.

Recent 7 Days To Die Posts

about 8 hours ago - faatal