I have used Pyrodex extensively in all my guns, with the exception of flintlocks, of course. When I got my first muzzleloader, a percussion Charles Daly/Investarms .54 "Hawken" in 1976, it came with a can of Pyrodex P powder, a tin of caps, 100 unlubed patches that I smeared with Crisco, and a fired .45-70 shell as a powder measure. It worked great. When the patches ran out, i used old t-shirts smeared in Crisco as patches to save a buck without incident for many years. I think we tend to overcomplicate things. For the first 15 years or so of my muzzleloader journey, which was pre-internet, I just thought Pyrodex was black powder. I used it in everything, shotguns, rifles, and many cap and ball revolvers. I didn't even know what a flintlock was back then, never having seen one. Pyrodex worked just fine, I have never had a misfire or even a hangfire when using it, employing regular old #11 caps. My guns have gotten nicks and scuffs on the outside, but the barrels look as pristine today as the day they left the factory. When I finally did start shooting real black, I found it dirtier (yes, even Swiss) than Pyro. My original rifled musket can get 4 or 5 shots with Holy Black before I can no longer ram a Minie Ball, I can shoot until I am tired of ramming using Pyro P. Same with my New Model Army repros, one or two cylinders bind the gun with genuine black powder, whereas Pyro gives me many more shots before I need to slide the base pin out to lube it. Never noticed any difference between cleaning Pyro or black powder. I use Pyro for all my shooting other than flintlocks, except when I'm gathering performance data over a chrono. I don't understand the vitriol for a powder that many of us used in blissful ignorance for decades without any problems whatsoever. I'll keep shooting my Pyro and be happy, as I get it cheap, and save my expensive and hard to get black powder for my flintlock forays.