Talked to wolverine_173 over PM and his insert is doing the same thing as mine, the insert is pushing out away from the frame and pinching the lower slide rail. As of now I have no visible wear on the top of the insert but it is showing wear on the flat left side of the insert (if you were looking down the sights). On the slide, mine appears to be pinching and wearing the right lower outside part of the rail.
Also, I don't think this area is a frame bulge. I don't have a digital caliper yet but it is obviously angled when looking at it with the naked eye, while the frame (at least in that area) is straight. When I remove the barrel, recoil spring/rod, magazine and hold down the trigger bar with the decocker I can feel and hear the slide actually hitting the insert as I slide it into position.
This thread makes me wonder if this insert could be contributing to my problems I have posted in the other thread:
Here. Possibly squeezing the slide to the point where it isn't properly feeding the ammo...?
the picture is showing where the wear is occurring. Also the left picture's arrow is pointing to the edge the slide hits.
Edit to add: I am just trying to get to the bottom of my fail to return to battery problem. This pistol is great in my eyes, other than the fact it is being temperamental through the break-in period. I'm sure after 500 rounds it will be good to go and it won't bother me unless the insert shifts even more. My first CZ was a 75B that was NIB and went 6K rounds before it had any issue, which was a fail to return to battery. I blame that one hiccup on the pistol be 600 rounds in on some dirty ammo. So you can see why I would like to get to the bottom of this.