My wife says “Don’t tell people stories that make you sound stupid. Let them figure it out themselves!” She may be on to something, but I’m going to share this anyway.
When I first began developing my Kimber Micro .380 grips, I didn’t realize that’s what I was doing. What I mean to say is I didn’t know the .380 and the 9mm Micros used different, non-interchangeable grips. I had purchased a set of aftermarket grips from a custom maker to use as a template for the profile. He sold them simply as “Kimber Micro”, with no caliber designation. Since I did no further research before I got started (a key element of my style), I didn’t realize that I was working on strictly .380 grips until later, when I tried to bolt them on a 9. Anyway, the main difference between the 9mm and .380 stocks is forward of the screw holes, the 9mm being understandably wider in this area. The bottom angle is slightly different, as well. Screw hole spacing is the same for both Micros, at 2.205”, by my measure. Both can be had with or without a relief cut for an ambidextrous safety.
That's it for now.