New reloader; are there powders that are useful for multiple calibers? By "new reloader" I mean I just got the Hornady LnL AP press and gear to get it set up. I decided to get into reloading mainly because I have a huge pile of 9mm brass (also starting to accumulate .357 mag and .223) that will be worth more to me as plinking ammo than as scrap brass.

I have the press set up, but I haven't bought any powder or primers yet because I'm not sure what's "good?" I visited the Hodgdon site in the FAQ and paged through Hornady's reloading handbook, but I'd like to hear the conventional wisdom as well.

Would I be able to find a single powder that is useful for plinking loads in 9mm/.357/maybe 10mm? How about .223 and .300blk? Or are these cartridges different enough that it just won't work?

Thanks everyone!