As everybody knows, modern manufacture upper receivers for M10/.45 have solid lower front portion, fitted for a two-piece receiver to frame pin. I have noticed, that during prolonged full auto fire the inner, nail-like pin, starts slowly pulling out of the outer, hollow tube-like pin. Does anybody have any suggestion how to keep the inner pin from moving out, or is there a single piece pin for modern manufacture receivers? Unfortunately, the original manufacture single piece pin with the center groove, fits only the original manufacture receivers with the small latch.