I concur with what woodmaster81 said regarding a light oil.

I do not use even very light oil at all in cold weather. When I hunt when the temperatures are low, I will strip the rifle down and the bolt and trigger will be cleaned of any/all oil - below zero F or colder for instance. Not that at my age I do that much cold weather hunting.

I recall a couple times in my youth (two instances, not me) where a 03 and 03-A3 Springfield's firing pin did not strike the primer hard enough to fire the cartridge.

If you have an enclosed trigger, having the sear slip due to not having a strong enough spring tension and thick oil could mean a rifle firing unexpectedly.

I prefer classic.
Semper Fi
I used to run with the hare. Now I'm envious of the tortoise and I do my own stunts but rarely intentionally