I look for powders that give decent velocity at the starting level. That way, if I get good accuracy right off, I can just call it done, and brass and barrel get a break. My requirements are admittedly modest since my shots are usually pretty close.
Berger recommends trying different seating depths at the starting level to determine the best position, then tweaking the powder charge. Gonna try that with their 115gr 6mm, then maybe with bullets from other makers.
