Not to beat a dead horse, but the answer may depend on what type of gun you are using... flintlock, sidelock percussion, or cap & ball revolver (which is essentially an inline). Generally speaking, inlines and revolvers don't have an issue with Pyrodex. If you are getting hangfires or poor ignition with a sidelock percussion, just using hotter caps may help. If it doesn't or you aren't satisfied with the result, a duplex load of a small amount of black powder down the barrel followed by a main charge of Pyrodex may improve ignition. Some people call that little bit of black powder a "kicker." You do not want to
mix the BP and Pyrodex, just drop the BP in first. The kicker charge should be measured, and that amount should be deducted from your main charge exactly as
@R Ellis described in post #9. I have not tried Pyrodex in a flintlock, but the late John Bivins recommended a duplex load as described, with black powder in the pan.
This topic got a lot of discussion during the blackpowder shortage that occurred after the Goex plant closed, just before the pandemic.
I had a Zouave rifle come into my shop last year, or maybe the year before, with a charge in the barrel that would not "go off." I found it was loaded with a sort of "trashcan Minie" bullet, which was easy to pull with an ordinary ball screw, and with
two 50gr Pyrodex pellets under it. I had to use the ball puller to get those out, too. The Italian rifle muskets are generally breeched with a sort of chamber in the breechplug. Flash from the nipple would have had a loooong way to go to reach those pellets, and I'm guessing the flame from the cap just fizzled out before it reached the Pyrodex pellet. Which may be a good thing... The bullet was quite heavy, and over a 100gr charge, launching that thing would have probably given the shooter a pretty good thump on the shoulder. Anyway, if you are shooting a gun with a chambered breech, Pyrodex pellets may be hard to light up without some sort of BP kick-starter.
I'm not a Pyrodex fan, and have no use at all for the pellets.
Notchy Bob