Re: IMR 4064 in 264Mag?
I just looked in my nosler reloading book (only book that even lists 4064 in that cartridge). Apparently 47.0 grains with 140 grain bullet was their most accurate load (for that powder). Its going 6.5X55 speeds (2700 fps) and has a load density of around 65%. Man this seems like such a waste. But you are right that tiny group on paper looks great no matter distance, speed, or application of load.
Learning every day.