BIGBOREFAN,
Data can be a bit difficult to find for that cartridge. I have a copy of the data from the 445 Super Mag article in the March/April 1989 American Handgunner and it lists from 31.0 to 38.0 grains of H-110 for a 240 Speer bullet. I would be damn careful with charges of over 35 grains myself!!! So you appear to be in the ballpark with what Steves Pages are indicating. I have used his pages and have always been successful.
You might also try the website WWW.DANWESSONFIREARMS.COM
They used to have reloading data for the 445 SM
I have a Contender in that cartridge. Never really got the M.O.A. accuracy I expected to get. I think there are better powders than H-110. I used AA-1680, WC-680 (surplus powder), and IMR-4227. Accurate Arms has data for the AA-1680. Good-luck with you Super Mag
BCB