I don't know why everybody starting out casting/hand loading begins with 9mm ............one of the hardest cals to load for with cast.
Start with your 38SP first. Get that one down good and then move into the 9mm. 45ACP is not that easy either, depending on your guns and the throats.
I like looooong cases! 38SP, 44SP/MAG, 45LC. Lots of room in there.
And it is your GUN BARREL that determines whether you need sizing, not the mold. "FIT IS KING" today. Slug your barrel to determine what you need to cast/size to. BTW.........I have NOT found a "bad" mold.........just bad casting/loading practices by the user!