I have read that it was developed by Bruce Hodgdon for the .22-250Rem. He used 38.0 (380) gns behind, either a 50 or 55 gn bullet. Not sure of the bullet weight, but that was the powder charge.
I tried it in the couple of .22-250's that I have owned and it never outperformed IMR and H4895. I also tried it in a friends .300WSM (Nosler) in an attempt to find the best grouping load. I have some on hand but don't reach for it very often. JohnnyK.