Cast bullets & a .44 mag

[muslmutt]

I can't seem to find my load book and need some data for 255 grain gas checked Keith style bullets with a BHN of 22 and using Winchester 296 shot out of a Ruger Super Blackhawk. A beginning and max load would be much appreciated.
Thanks.
Matt

[Graybeard]

There are no gas checked Keith style bullets. Ol Elmer designed only plain base bullets.

The bullet you are referring to is most likely the Thompson design from Lyman Mould 429244. The answer to your question is 24.0 grains tho these days some manuals are advising a half grain up and down from there.

I prefer 2400 for less than max loads and for years have used 17.5 grains of it with that bullet.

[gray wolf]

296 should not be down loaded below what the book gives,
read the warnings, great for max loads. 
The 2400 is a little more flexible.

[anachronism]

Loading data is on line:

http://data.hodgdon.com/main_menu.asp

As noted above, there's not much room for change with 296.