robhof
It's cleaner and you can use less, just add more filler. I use it in mine, be careful of compression as 777 likes light compression, heavily compressed it seems to delay fire and burn erratic. I would NOT fill my chamber with it as it's 15% stronger/hotter than real black or Pyro and the Walkers will shoot loose with many heavy rounds of hot loads. There's a reason they all say black powder only.