Back in Aug. I posted a problem with a SS 1/8 AR Bbl. It would not group under 4"@ 200yds and would really tear up a patch when cleaning. I happened to run into a shooter who owns a borescope. It turned out that the chamber went right into rifling--No throat or freebore at all. I went ahead and had it throated for SMK 77's,now she holds a honest 1 1/2" @200. The Bbl has no manufacturer stamp and I don't remember it's origin(trade,gunshow,I have too much stuff-don't know).Anyway maybe this will help someone else in the future.