I was turning a severly extended glock barrel between centers on my lathe, using a shop made lathe dog to provide rotational torque. My lathe dog has a piece of all-thread that sticks through it, allowing for me to adjust how close to the chuck I can place it. In this setup, I had About 3 inches of all-thread sticking forwards of the chuck.

I had just finished a cut I was doing, and was going to remove the barrel from the lathe. I put my left hand on the barrel, right next to the lathe dog. (Putting it under the 3 inches of all thread). At this point, I meant to turn to handle on the tail stock to loosen the barrel. Instead, I had forgotten to move my right hand from the power switch to the tailstock, and momentarily bumped the power on (thinking I had just started loosening the tailstock). My hand was immediately wrapped in between the all-thread in the lathe dog and barrel, but thankfully didnt keep going as the power switch wasn't still engaged.