OP , why are you wearing a glove?
My SP5k has a small wobble, nothing too bad.
OP, just checked my SP5K. Also a similar wobble, nothing that has affected its function. IIRC, my last SP5K and even an 87' HK94 had similar mag play, which I figured was just normal for the platform.
Just use ETS mags. Cures that wobble in a flash!