At this site http://www.gmdr.com/lever/pistolpowi.htm there is a body of data that seems to be well done. It is for light loads in large rifle cartridges.
Additional data here: http://www.gmdr.com/lever/lowveldata.htm
The go to powder is W231/HP-38, followed by Green Dot and Blue Dot. The conclusions reached seem to make sense to me, however I am quite new to this light load business.
Curious to hear anyone's comments on this body of work.