I consider "sling shot" to mean grabbing the rear of the slide between my index finger and thumb, as if using a sling shot. I used this method for a while, for Glocks, but when I acquired SIG P229s, and dumped the Glunks, the abbreviated slide serrations of the P229s taught me to use an overhand or "power stroke" method. I often default to using the slide stop (slide release) when shooting right-handed, to the extent that power-stroking can be called my lefty method, and the slide stop my right-hand method. (Yes, I practice quite a bit with each hand.) I had learned handgunning in 1983 with a 1911, and had learned back then to use the slide stop. I didn't start sling-shotting Glocks until 2002, so the slide release method had a big head start.