It was the data that changed, not the formula, at least for #7, when I contacted the factory. I remember using datat for #2 from a Hornady manual from about 10 years prior, and wondering why I was getting such wild results - the company had gotten a new maker for the #2 and the formula had changed - my fault for using old data.
I still like #7 for 9mm and #2 for 38 special, as well as 1680 for 7.62x39mm.
