It's been discontinued. It was offered up until a year or so ago. It is a useful powder in some magnums and similar cartridges. I have loaded it in 7MM Mag and .270. There may still be some available out there, since it was pretty popular with some reloaders. It is a very slow powder, compared to most others. It probably was slower than H450, H4831, and Winchester 785 if you can believe some of the powder burn rate comparisons. I believe it was extruded, rather than the usual ball powder that Winchester offered. You might take a look at www.wwpowder.com and see if there is some data still offered. I believe the new Supreme 780 has replaced it.