I thought about doing the same thing 8 years ago on my C-91 ,unfortunately I ended up thowing the plastic POS in the trash. It just cant be done because the carrier is never going to squeeze that peice of plastic enough to engage the steel stock buffer. Plus,the screw holes are recessed on the metal buffer;so when you tighten the screws down tight,they RIP the plastic buffer techs ears. Either way,been there DONE THAT! Good luck though brother.