Pyrodex P is for pistols - uses 90% by WEIGHT of an equivalent BP charge.. Triple 7 is also good, and uses 85% by WEIGHT of an equivalent BP charge. Both clean up with water, and notwithstanding what folks say, they BOTH need a quick clean-up, post shooting.
Pyrodex P is energetic, but Triple 7, by comparison, is just plain frantic. Smells odd, too, a bit like sugar beets - not surprising, since it is a sugar-based propellant.
Your choice - I use both Pyrodex Select and Triple 7 in my two revolvers, but there really is nothing like the holy black.
tac