Typically, the frame is softer than the bushing. But, is the 952 frame steel or aluminum?

I've used the Loc-Tite trick on many 1911's. Degrease both frame and bushing/stud, CAREFULLY (don't want any to wick up the threads on the grip screw) apply red Loc-Tite to the frame or bushing and tighten firmly back into the frame. In half an hour or so the screw should back right out.