I have used nothing but BB for years on the inside of the barrel and the outside of the barrel, I even wipe the outside of the scope with it. During rain and snow it actually repels the water. I never noticed any accuracy problems but anyone that has I would like you to post your findings of your likes and dislikes of BB. I would appreciate it. Im willing to change, if change is good. I also ordered 2 bottles of the Montana XTreme to try out. I have always been taught to NEVER use any petroleum based oils in a ML barrel. Have I been told wrong?