Since .380 and .45 are lower pressure loads, it seems you really could do to have two powders, rather than one. If you just have to use one, I would try to get along with 231/HP38. If you can go for two, I would probably add HS6 for the other three calibers, or maybe AA7 if you happen to like Accurate Arms powders. I have less trouble buying HS6. AA7 can be tough to find.