I'd start with some Triple Se7en FFGor Pyrodex RS powder and some 250grHornady SSTs or T/C Shockwaves (basically theexact same thing).Start with 80 or 90gr powder and increase up to maximum (modern inlines usually have a 150grmax charge, reduce by 15% with Triple Se7en but notPyrodex), or stop when your groups start getting poor. You now know where to experiment for best group size,or forbest combination of accuracy and power.