BT53, 50 grains with the 225 Sierra, 51 grains with the 225 Partition. I wasn't working from a book, I was using JB's data, and I think that's a bit more powder than he was using so... work up to it etc etc.
IME, the Sierra is an excellent practice stand-in for the Partitions. Those Partitions are pushing $50/box!! I can't be flinging them around willy-nilly <g>. But they do fly the same out to 400 yards or so.
