I use 3 grns Herco in mine but have never tried any other powders so can't really recommend anything else. If Alan says blue dot is ok
then you should be ok to give that a go. Essentially the gun is a 38 so i would have thought any Mild 38 load recommended in the manufactures
load data would be usable but would recommend finding some Herco. 3 grns really shoots well. I have used 5.0 grns Unique in my 357 LBR
and the Lee manual does list it as a 38 load at 3.2 grns with blue dot listed at 5.3 grns with a 148 grn wadcutter. Given the difference in Blue
dot and Unique loads i would be very wary of using Unique myself, even a light load of say 3 grns could be too much.!
Three grns of Herco may not sound much powder but believe me when i say its plenty.!! Ow, and don't be put off if you can hit a barn door to
start off with, they take a bit of getting used too. Tim