The various lubricants noted in Army manuals reflected where they were used. Oiling in the desert invites trouble, in Korea it froze etc. None of that has anything to do with nursing 75 year old rifles through another year of life in the US. I always oil and grease carbines and M1rifles. They need all the help they can get.
The AR 15 is a design with tiny by comparison bolts and attached parts. The rifle uses a barrel extension as well. It also has a operating rod system that is a bad joke. Two fingers??? If you start firing an AR that is the least bit too dry, and you happen to smack the forward assist, you have a serious problem. A rifle with a live round stuck in the chamber and you must knock it out with a cleaning rod. I use plenty of teflon oil and some grease on that carrier and bolt. I'm not in Iraq and nobody is going to inspect how I keep my weapons.
Using light weapons oil in tiny quantities on a carbine because a manual said that's what I should do, makes no sense today. There are no Ordnance Level people any more and parts are drying up. Pamper that Carbine.