Received this email today in response to an inquiry about Win231 Powder.
"Winchester 231 certainly has been hard to get. The plant that makes Winchester powders does not want to make 231 as well as a few other powders. These older technology powders have different chemistry than the new powders...
Like an idiot, I bought some 124 grain Berry's FP bullets to start loading for my 9mm. Had I known how little information is out there about these things, I would have made a different bullet choice. I should have bought the RN version. Oh well.
Everything I read says to use data for lead...