If you're running all weights, I'd suggest Solo 1000 - cheap, low SD, accurate, available, clean and meters well - as a bonus, it fills the case so a double charge will be spilling out of the case and easy to detect. If you don't run heavy weights, like 147s, try Clays - it has the same attributes as Solo 1000 (except available these days), but it's a little too fast for 147s in my experience. Both these powders are about as smoke free as you can get with lead. I've used quite a bit of 231 with lead and it's accurate, but a bit dirty and smokey as hell.