Frame rails, grease is fine. Not around the internals. I had a Kimber TLEII when they first came out. My first 1911 and read up about the 1911 being designed to be greased. I used grease for about a year and then attended a shooting and tactics SWAT class with other team members. About 3 hours in my trigger would not reset and the firing mechanism was "locked up". I was loaned an extra Glock 21 someone had and had to endure constant ribbing and teasing about my "John Browning Boat Anchor" until the end of the day. For lunch the next day, I shot up to a local gun shop that had a gunsmith who was retired from the Anniston Army Depot where he worked his entire adult life as a small arms repairman. 1911's, Springfields, M1's, M1 Carbines, M60's, 240's, Ma Deuces, etc.
The guy yelled for me to come around to the repair bench and asked "you use grease and gun scrubber or brake cleaner don't you?". I was like "yeah, how'd you know?'. He took his dental pick and fished around inside the frame near the lockwork and removed what I will call a "booger". It was a small chunk of hardened crap that had locked up the hammer/sear/disconnector etc. I said "what the hell is that?". He said never use grease and aerosol solvents. I used grease on the bottom of the slide that runs over the disconnector and it had shaved off grease. He said when I used aerosol solvent that the solvent didn't totally dissolve the grease/powder fouling that have gotten down into the lockwork. He said the repeated process of fresh grease, solvent, fresh grease, solvent, etc. had caused this nasty "pearl" of crap to be formed that got so big that it jammed the lockwork of the trigger! He said grease good on the outside rails but oil everywhere else.
