Promo
I have had some very good results with Alliant's PROMO powder. It is a bulk powder, sold in 8 pound cannisters. Anywhere between 3.6 and 3.8 with a 130 grain cast bullet works great. Over 4 grains and I would switch to another powder type.
Have used Unique too, but ended up dropping the recommented load down quite a bit. Dropped it down so much, that PROMO is a little bit less with the same results.
SuperField works well too. You will probably discover that if your barrel is four inches or a little more, fast burning powder works best. My pal Len uses Bulleseye and Titegroup will good results.
The best bang for the buck stills remains PROMO.