I tried 64.5gr of IMR 7828 with the 175gr GK and accuracy was good at 3/4" at 100 meters. Velocity was: 2820, 2807 and 2818.
This was with new W-W brass and Remington 9 1/2 primers, 3.300" OAL.
I loaded some more last night - up to 65.5gr - and I will post the results.
