I load them to a COAL of 1.15. I've made a couple thousand this way so far - most of these are fed through my G34 and a LoneWolf 9mm conversion barrel in my G23, with some going to my 9mm ARs.
There may be better powders than Unique, but I lucked into an 8lb jug of the stuff. I have a few single pounders of other powders (bullseye and w231), but I haven't bothered with them yet since I have so much Unique.
I started my load testing with 3.7grains, which worked, but the brass was getting dropped really close to me (basically at my feet). I prefer there to be a little more "oomph" for the ejection cycle, so I bumped it up to 4.0 grains. It now ejects farther out and more consistently, so I've stuck with that. Plus, my 9mm ARs cycle it without problems, so I can't complain.
I also tested with 4.3 grains, but it didn't seem to gain me anything, so I've stuck with 4.0 grains.
-bob