Thanks for the responses. After getting confirmation from Henry that I could use +P loads I went ahead with the loading project.
I used Unique, AA9 and Lil Gun (the powders I had on hand). The winner in terms of accuracy and velocity was 23.5 gr. Lil Gun. This was the starting loading as listed by Hodgdon. I didn't bring out the chrono but it's listed at 1300 fps from a 7.5 inch revolver. With iron sights we were getting five shots to cluster into one ragged hole at 50 yards.
