For some silly reason, Lyman has data for this bullet in the 45 Colt section of their Ruger/Contender listings. As usual with Lyman, the data looks really "soft", showing Unique as the slowest powder on their short list. I'll get it for you if it'll help. Casull data for heavier 452651 seems to be available. Fivers advice about looking at 300 gr loads is especially sound for this project. The Lyman moulds I've used from this era all cast heavier than nominal advertised weights, and you ending up with 300 gr. bullets from this mould wouldn't surprise me in the least. For reference, my 429650 ended up at 320 gr, and 452651 ended up at just under 340, all with a lino/WW mix.