I agree with PAJack, My best accuracy also is with IMR4064 with IMR4350 second.
This is with both 139 gr and 150 bullets. I also found, by chance cause I ran out of CCI large rifle primers, that when I loaded a batch up with 42 gr of IMR4064 and used Remington 9 1/2 Magnum primers, my group size shrank from 1" down to 5/8".
I am thinking that this is due to a more uniform ignition of the extruded powder.
I also have been using the Lee factory crimp die for all my cartridges. It seems to help with accuracy consistancy.