Lubriplate slf 0 aluminum based white grease on rails. It's super thin and holds in place. Believe it or not my semi autos actually perform better with it, especially 3rd gens where its metal on metal. I'm still using Hoppes oil where I need oil.
Find lubriplate at lubrikit.com. I put some on the metal parts in my Sigma's sear and I believe it dropped the trigger from 7# to 6#. No, I'm not working on commision, just like the stuff.

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