The # 12 Speer manual has from 45-49g of IMR 4064 traveling up to 2723 fps. I use Hornady, and Winchester 170g bullets and 49.5g of IMR 4064, Rem brass, and Win primers to get 2730 fps with my sportered Turkish Mauser. I also had a very accurate load using 48g of Varget, but it was only going 2450 fps. Winchester 748 works very well with my 150g Hornadys, and I plan on trying it with the 170's too.