In my opinion, despite what the burn rate charts say, Power Pistol is much slower than HP38 and a little slower than Unique. Everyone thinks Power Pistol is only for "high performance" semi-auto cartridges, and it works well in those applications, but to me, it really shines in big bore revolver cartridges.
In .44 Special and Magnum, and .45 Colt, it is SUPERB. Low recoil and pressure, greater velocity over HP38 and Unique.
I do not have increased flash in those cartridges, nor in .45 Auto (which it is also good for). However, in 9mm, yes there is quite a bit of flash.
Brian Pearce has shown excellent results using PP in his "Handloader" articles for revolver cartridges. I have not yet found a load he lists that did not shoot sub 2 inch groups at 25 yards, with greater velocity than other similar powder loadings.
Just to give you an example, I chrono'd the "Skeeter" load in .44 Special of 7.5 grains of Unique under a 250 grain LSWC, and got 975 fps out of my 5.5" barreled Blackhawk. Using 8.5 grains of PP, which gave similar recoil (maybe a touch less), I got 100 fps more. That's not max loading, either.
Here's a mid-range .44 Magnum load that works like a champ in my 629.
I recommend giving PP a try. Of the powders you have, it is closest to Unique. I prefer it over Unique, now. Meters a lot better, and is cleaner.
