Not at home , so can't look at my manuals.....appears like Larry has put you on the right track with his info.
I understand what your doing...I have a tendancy to try to consoladate my powder uses also , but sometimes ya have to break down and get the best powder for your need. I've been using IMR 4895 for my .308s for years. It may not be the best but I use it in several other rifle loadings. It seems 4227 is more suited for the small cases. good luck
regards , irold