I did some chronograph testing this morning and got some interesting results. Rifle: E.R. Shaw mark VII. 22" barrel powder: allaint power pro 2000mr and Imr 8208. I was interested in alliant power pro 2000mr powder because of the promise of 2725fps with a 200gr bullet. I also tried IMR 8208 because it looked promising for 180 - 200 gr bullets. Results: 52gr of power pro 2000mr. 200gr Interlock = 2664 fps avg. 200gr Accubond = 2678 fps avd.
Interesting that with the power pro I got lower than listed speed but with the 8208 I got faster than listed speed. Accuracy between the two powders was too close to call. I think I'll stick with 8208 for now.
I also tried power pro in my 308 win. With 50gr of powder and a 165gr sst I got 2962 fps avg out of a 26" barrel!