Power Pistol is the best 40 powder going. Clean, meters well in anything that works properly, and offers performance from mild to wild. One drawback is flash, it has a bright white flash. Universal is good with jacketed bullets but it is a little sensitive on OAL and pressures, small changes in load can make big pressure differences. Blue Dot works OK. IMR SR4756 works well. Winchester Super Field is a VERY good 40 powder, good performance and low flash and offers very good accuracy for me and everyone that I know that has tried it. I have tried a lot more powders than above but the ones listed are the ones I have found work well.