Mark, Youre talking the difference between modern plastics and the early ones, and I agree completely. But pheno-plastics, with and without fillers were used in prewar and war time pistol grips. When used without fillers, they were brittle and easily chipped or broken. Example: the early 38-H grips which contained fillers, and the A1 grips which did not. The A1 grips break easily while the early ones which do not, but both are a "plastic". Early "plastic" grips are correct on late HSC's. some Model 34's, Dreyse, Sauer, and Walther, and some others. Let's not argue about formulas. For most purposes plastic is plastic.