Hmmm, at first I thought mostly my left hand worked the slide, but I had to rack the slide a few times to find that both hands moved equally.
I am right handed, so the pistol is held in my right hand with the barrel pointed to my left centered on my chest:
- My left hand is cupped over the slide with my left thumb/palm making full contact with the left side of slide (thumb on the serrations)
- Left index finger is bent down and in contact with the right side of the slide
- Third, fourth and fifth left fingers are held around the ejection port to catch any ejecting round
- With elbows bent and wrists locked firm, chest muscles are used to push the slide back