For what it's worth, I'm using 43.2g of 4064 in Lapua brass with CCI BR-2 primers and the 175g SMK pills at 2.820" COAL (mag length) in my PRS rig. I'm getting about 2715 fps (ES ~ 15 fps, SD ~ 6 fps for 10 shots) from my 26" 5R Bartlein/Defiant setup and maintaining 0.3-0.5 MOA 5 shot groups...