I found this on www.6mmar.com. Opinions?
For the bolt lugs in particular you need a very high viscosity sticky lubricant because the lugs are a “severe duty” application in that they open fast under pressure and get very hard use otherwise. Most greases are no good because they don’t stay around. The best lubricant I have found is Phil Wood Tenacious Oil (it’s like a sticky 90 wt. gear oil) and you can buy it for $8 or so at your local bicycle shop or on the internet in its own applicator bottle. I have built up a lot of AR’s over the years and seen others come back for re-barreling or other work. Some have an enormous amount of bolt wear (and a corresponding dramatic increase in head space) because inadequate lubricant was used. The owners thought they were using a good product, but it was not. A lot of the favorites are no good either (and I am not going to name names).
- Phil