According to Vihtavuori:
45 acp 230gr FMJ-RN Hornady N340 6.8gr 974fps 1.26OAL
They don't list data specifically for lead bullets but since lead usually shoots faster than jacketed with the same powder charge this should be just what you're looking for. I'd start at 6.5gr with the LRN and work up or down from there as needed.
John
http://www.handloads.com