READ, Must clean new barrel
Just put this 8.6 BLK on a new upper for my LR-308. Then I went to clean the unfired barrel. It took me 3 hours. There is a dried substance (I presume for button rifling) that is difficult to remove. I started with normal cleaning products (oh yea, I have been cleaning rifles for 40 years), then tried lighter fluid and then progressed to brake cleaner. None of these will effect this dried material. It looks like dried brown shoe polish. Aggressive 338 bore brush (plastic bristle), then push a patch thru with 338 jag and you will get this material out of the rifling. You can put it between your fingers and it just flakes, falls off. It is not dissolved out all. Repeat process for hours and I finally got to 98% clean before I test fired 2 rounds for function. I still got more dried material out after firing and subsequent cleaning. I would not shoot your barrel without cleaning. I used new Gorilla/Starline brass. The shoulders moved .007 and a 338 bullet could not be set in fired case.
