I'm on the current experimental as of 16 July 2014.
I have found that, at this time, the 1911 is wildly inaccurate. After several point-blank shots missing zombies charging straight toward me, I test fired a carefully aimed headshot at a stationary zombie about 20 meters away. I was not short of breath. I was zoomed in fully. I held my breath with my Hold Breath key.
About half a second after firing the shot (lag), I saw the bullet impact a building about 20 meters behind the zombie. The shot had gone at least a full foot over the zombie's head, despite my aiming at the middle of its face from 20 meters away.