All mounting hardware was degreased, torqued to spec and Loctite. Have tried factory and handloads 150, 165, 180 grains. 165 seems the best on both rifles. The Ruger American is fairly new so I may be able to get to MOA but the Vanguard, I don't know what to say, I have tried Barnes, Hornady, Speer, and Gamkings and the only thing that shoots halfway decent is Gamekings. The rifle is thoroughly cleaned after every session, I guess the next thing is to see if another scope will help