Like Fishinfool said,you're almost there.I don't load 300 gr jacket bullets but 265 lead.One thing I found out is when you are close to the top end pressurewise,a very little might make a big difference.I've developped a certain load for 1 of my 44s(DW)during wintertime( aprox 10*F).Everything was looking ok.But when I shot these same loads during summertime(aprox 80*F)I got flattened primers.I backed off .2gr and everything went back to normal.
All this to say that if you want to keep increasing your load,don't do it by more than .2gr increments and take note of all other variables.Let's keep our sport safe.
Qc