Lyman has a lot of .38-55 data in their manual, as does Accurate and the Pet Loads book. The powders listed by the original poster are all really too slow to be appropriate for top cast accuracy, although som emay work for hunting loads. For target accuracy, powders like AA5774, WW296, 4759, 4227, and 4198 are all proven fine performers.
I have two .38-55s - neither by NEF/H&R - and shoot a lot of cast bullets through them. The RCBS 250FN works very well, and with the gas check allows good velocity without leading. But it may come out of the mold too small in diameter for you; mine casts at .3775" in my allow and shoots better in my .377" barrel than in my .379".