It hurts absolutely nothing to keep the chamber and bolt nice and wet during your shooting session.
Absolutely true. I put a couple of drops of oil on my steel cases and roll them around before loading them into the magazine. This helps break the friction between the case and chamber and improves reliability of extraction.
The shooting community has totally forgotten oilers used in the early semi automatics. Oilers and greased ammunition were messy, but there were plenty of fielded machine guns that used oilers, the Japanes Nambu, all of the Italian machine guns, and the 20mm Machine guns used by the Brits in their Spitfires, our aircraft, and the Navy. https://en.wikipedia.org/wiki/Oerlikon_20_mm_cannon
My recollection about 150,000 of the 20mm gun were built and used up to Vietnam. They used greased cases or they would not cycle.
Page 106 of manual: http://hnsa.org/doc/gun20mm/part4.htm
Oilers and greased rounds went on the ash heap of history when the Allies had enough rounds fired at them by German machine guns with fluted chambers. The flutes use gas pressure to break the friction between case and chamber, don't require an oil can or grease and is the better mousetrap.
What I don’t understand why all firearms don’t come with fluted chambers as they improve extraction.
The LaRue XTRAN 223 chamber is fluted, it is a great idea:
Failing flutes in an existing rifle, I don't see any reason why not to lube steel cases outside of the mess.