Everytime one of these types of questions pops up I have to go check in my reloading manuals. In the Lymann Cast Bullet Handbook it shows regular loads and higher pressure loads intended for Ruger and the T/C Contender only.
It's showing 6.5 minimum to 7.4 maximum grains of 231 with 250 grain cast boolit for the regular loads for revolvers. Then it shows 7.4 minimum to 10 grains maximum for the Ruger and T/C Contender revolvers.(T/C is not a revolver now that I think of it)
Seeing as you're putting these through a lever action rifle, I'd think the rifle wouldn't grenade itself if you worked up from 7 grains of 231 while watching for pressure signs. Just one guys humble opinion though. Work up your loads slowly, and have fun until you can get a slower powder.
