Mz5,
I just reread the thread and missed your comments on the characteristics of the powder. It sure looks extruded to me. It is the shape of tiny rods or pieces from a mechanical lead pencil. It looks just like RL-17, H4350 etc.
My biggest disappointment is that this new Power Pro 4000 MR was presented as another long burning curve powder similar to RL-17. 6mmBR said something to that effect last September AND a representative from Alliant said it as well. I don't believe it has the same formulation as RL-17 or it would have beaten it in some of my tests.
To its credit it seems to have some nodes that were accurate with minimal velocity differences. I will be shooting one accurate load in that 7 rem mag soon to see just how consistent it is. While velocities were down compared to other powders it might be a good one for tight groups. FYI I have not heard from the Alliant Rep I e-mailed. I wanted to know if it was an extreme powder. RL-17's canister says it is, 4000 MR makes no mention of it.
