I am getting ready to try out a new to me powder cast Boolit load , but have ran into a problem , I recently picked up a lb of Reloder 7 alliant to try in a 7x57 mauser when I check the Lyman 4th edition it lists Rx7 - have I made a grave mistake in my purchase ? Is the load data for No.7, Accurate or Reloader 7, Alliant ? I guess I'm kinda easily confused but I better check before loading .