My buddie has loaded his using both of the powders you mention. His results were that while Retumbo gave higher velocities before hitting pressure signs, the H-1000 gave better case life at the same velocity. Both were equally as accurate as the other, and both were shooting easily around 1" at 300yds. This is from a factory Sendero which has one of the Defensive Edge brakes installed by Kirby. He has them seated to book OAL which comes to .125" off the lands of his rifle. As for the exact load I couldn't tell you off the top of my head. I know they are running a bit over 3200fps. Hope this helps.
