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.
Thee was something else about the recoil spring for 3-4” 1911s should be using *flat wire* springs instead of traditional round springs.