Hey guys, I've been struggling trying to find this information out, I have looked everywhere and even emailed SIG. Their response was not really informative at all and was worded (not quoting here) "we're not really going to tell you what parts are MIM however, we can assure you that every part is of the highest quality". OK so.....what the heck does that mean?!! I know when they first started producing 1911's there were absolutely no MIM parts. Now I've heard different. The only thing I've read in other forums were maybe the slide stop and ambi safety, quite possibly the grip safety. Does anyone know or know how to find out? I'd like to replace them. I have switched out my slide stop for an ed brown, wanted to anyway b/c of the color combo I wanted for the sig. Well thanks if you can help me out!