I posted earlier about my Competitor experience....bad. Since I bought a Rival Steel. Great gun so far. I generally shoot a couple hundred rounds per week. The rival has made me set aside my Smiths for the time being. No problems, really like it.
It is the striker spring holding the slide slightly out of battery when the slide is closed softly , when the striker drops the recoil spring moves the slide. When dry firing drop the slide harder or give a push on the back of the slide with your thumb and most if not all of the movement will be gone.