For handgun, I've always tried to pick the powder that gave the least chance of double charges. Win231 pretty much hits the mark on most. .38 Super is about the only cartridge I've loaded that won't hold enough of it in one drop to reliably make power factor. Most other cartridges, 9mm included, it is easy to spot a double powder charge as I'm about to set the bullet on top it. That's one thing I look at for every single round produced on a progressive press. I use 231 on all other handgun calibers. It's messy, but it gets the job done.