The lightest rounded (dome) shot of the JSB company. The abbreviation RS comes from the English words "Rapid Speed," due to the fact that RS shot provides higher velocity. They are also characterized by a flattened flight path. The acronym also alludes to the automotive industry, where sports car models also get the RS (Rally Sport) symbol, due to the fact that they are lighter and more powerful than regular models.
If the power of a windshield is 16 J, the exit velocity is 255 m/s.
