yeah I forgot there is some data for the RL26 and 270 weatherby on alliants site. Not anything remarkable because like John said the burn rate is faster than I assumed which was thinking it was as slow or slower than RL25. IMR 7977 might be a good choice with no manufacturer's data for it as well as RL33 with out any data published for it either.
It sounds like imr7977 is real close to H1000. Not sure how RL33 lands in the spectrum.
