Power Pistol is the same size flake as Bullseye and it meters like a dream. Power Pistol does too.
As for loads, they should be easy to find both at Alliant's website and in newer manuals.
The only downside to Power Pistol that I have heard is it's flash. It seems that some folks have tried to use it for self defense rounds only to find it has some bad characteristics around sun-down!
If that doesn't matter to you, have at it!