Great info. I’ve never heard of that before.Buddy got a Kimber Custom 2 tone 45ACP and I had issues making ammo run through it reliably.
I then took the gun apart and colored a brass case all over with a sharpie.
I found the area in the chamber where 45 ACP was stamped was causing all the issues.
The chamber stamp is done with too much force and dents the chamber down inside.
After I found the issue I fixed it and it will eat anything now with 100% reliability.
Read here for more and a picture.