There seems to be questions and discussion on these powders interspersed throughout the forum. I thought I'd give my own two cents. As always, your experience, guns, equipment etc. may vary. I have quite a bit of experience with triple 7 and Pyrodex powders. Both "rifle" and "pistol" versions in percussion revolvers and muzzleloading percussion rifles. I've used these powders in the northeast, in the humid summers and bitter winters. Here is what I've found: Triple 7 It offers more energy per volume than either Pyrodex or BP. It's fouling is very dry, almost like granulated sugar. VERY easy to clear. A single wet patch will clear the lion's share. Can form a crust ring at the chamber in rifles if compressed too tightly. Not a deal breaker as it's easy to clear. More cautious loading prevents it. Big disadvantage is that this seems to be the most finnicky powder for me in very cold temps(10s and subzeros). In these situations I often need to charge under the nipple to get it to fire or use more caps before it discharges. Its smoke is least like BP. Not as thick and it has an acrid odor. Pyrodex This is the substitute that is most like BP in performance. It's quite reliable even in cold temps for me but in this BP still has an edge. Volumetrically, its power is the mirror image to BP. There seems to be a prevailing claim that it is noticeably more energetic. I believe that this comes from revolver shooters due to pyrodex being quite a bit more compressible than BP. More volume can fit in the chamber. I can fill the powder just about to the mouth and still squeeze a ball in far enough. Contrary to another common claim, I have not found it to be more "corrosive" than BP but exactly the same. I clean my BP guns same day as I shoot them and surface rust can set in with either on bare parts over the course of hours. No guns suffered permanent rust nor pitting in my possession which I think has more to do with my choice in oil than anything. Its fouling is a tad drier and slightly less sticky than BP. Smoke profile seems just like BP. Familiar sulfuric odor. If I had to be "stuck" with a BP substitute, I feel I could make do with Pyrodex. Triple 7 can do in a pinch for me in warm weather. As I'm not, I'll choose real BP as reliability trumps all. What is everyone else's experience?