Mark,
I definetly do not think you are crazy using the synthetic oil on the machine guns, and I would do the same thing. The only difference here is that the stainless steel will tend to "gall" if not properly lubricated with a high pressure grease. The oil will tend to "squeeze" out more than the grease will. Although I think the synthetic grease is the besst to use, I have been using high pressure lithium grease from the Army (Artillary Grease) on my M1A since I could not locate a good synthetic grease. Then Neil came along and I found out about his great grease.
Marvin
P.38 Forum