THE SMART TRICK OF AK4D THAT NOBODY IS DISCUSSING

HK states they do a number of ways in building that are proprietary . Not passed on to licensees?So what else differs on these to make a good clone? I do know the bolt carrier has a scalloped notch in it, the grip frame is marked "S-P-A" plus the sights are lopped off with an extended rail on leading, and naturally the Spuhr stock and hand guard, a