As far as lube goes, I was recently hit with the epiphany that, if Mobil 1 synthetic will work under pressure and at 10,000 rpm in an engine and costs far less than any gun oil, why use anything else? What could any gun lube offer that modern synthetic motor oil can’t do?
That's an excellent question, but I cannot do it justice.
I've been using Mobil 1 in cars since 1975. There have been several generations of it since then. I have not really kept up with the subject.
One of the advantages that I recall is that the molecules were less reactive than those in conventional oil, and that they were much less likely to form sludge when combined with combustion products.
Another is that, because the molecules were of uniform size and weight, they did not evaporate at different weights, and the viscosity did not increase over time.
They also provided greater lubricity without adding things like teflon.
Practically speaking, only the third of those means much of anything when using it to lube a bolt or a slide, and we do not need to avoid teflon.
There are reasons why other lubes
may be somewhat better than
today's Mobil 1 for lubricating firearms. The EPA has put limits on the amount of zinc and other additives that can be used in motor oils for street use. That detracts from the lubricity of the mixture. That does not apply to the Mobil 1 Racing Formulation, which is not for street use.
One other thing. and I'm not sure of this one. One of the reasons that Mobil 1 does not form sludge in automobile engines is said to be that it leaves less of a film on cylinder walls. That could mean that it does not stay as well on gun parts.
Keep in mid that an engine oil serves to cool, to prevent metal-on-metal contact, and to clean. It must
flow. It is preferable for gun oil to not
flow very much.