Last week, I found a YT video about Kimber 3” & 4” 1911s, and the Kimber guy was saying that both the recoil spring needs to be replaced from 17lbs to 22lbs, to eliminate FTFs and jamming. He also recommended to replace the guide rod to 100% fix the problem. Also choosing specific ammo to run in the gun.
Might be in these vids:
https://www.youtube.com/results?search_query=kimber+recoil+spring+replacement+on+2%22+3%22+models
Also, the recoil spring in the Kimber smaller 1911s were too short and needed longer springs to carry the battery fully back to fire position. Wilson Combat and several other mfgrs make them.
If I can find that Wilson Combat video, I’ll send it to you.
You’d think Kimber would address those problems themselves.