There used to be a video which answered that question ..... too graphic for here, but it showed a man, hands shaking from adrenaline, trying to rack the slide while getting repeatedly shot, before he slumps over.
So, having seen that video you can find online elsewhere if you look for jewel store robbery videos, I'd say chamber, or learn to throw a pistol really accurately and really hard while running away. (This might require practice.)
I practiced NOT turning on a light switch, so I can keep my finger off the bang switch, that required less practice, but I still pay careful attention and have a healthy respect for that machine which makes thunder and lightning.
Of course, never point the end that has a tube on it at anything you don't want to destroy or kill, ever, even unloaded.