Sandburr, That's one round that I have not loaded for in about 25 years. I shot with a friend who shot a Hawkeye in 256. I believe that he used WW296, but I can't tell you any more. Unfortunately, he's dead so I can't even ask him. Sorry.
I'll see if they have anything in Cartridges of the World when I get home later tonight. If you check out Paco Kelly's Chronicles at www.sixgunner.com I think he has some info on that round. Is this a rifle or a pistol?
I got home and checked and the only powders listed in the book are H4227 and IMR 4227. The last one is just listed as 2400 and they say the source is Hornady. The loads for all powders were between 14-16gr. I know this isn't much help, but that's all I've got.
This is a rifle. Marlin md.62 found a man with it that had bought it new and shot 1/2 box of shells and I got gun and other 1/2 box of shells!1 the shells are Win.60gr.hollow point. I will try relopading with formed 357 cases. Thanks for any help!!