I have found over the years that IMR 3031 is about the best powder to get close to powders used way back when the rounds were first loaded by their military. I have used it in 8x50 Lebel, the .303 Britishicon, 6.5 Carcano, 6.5x55 Swede and of course the 6.5 Japaneseicon to name a few. While not always the most accurate it does seem to deliver acceptable accuracy in these cartridges.