I chronoed my Black Diamond today -- the results:

[HKP7PSP]

240 grain XTP:

1 Pyrodex pellet: 1096fps, 639 ft/lbs at muzzle, 512 ft/lbs at 100 yards, 432 ft/lbs at 200 yards. 10 ft/lbs of recoil.

2 Pyrodex pellets: 1520fps, 1230 ft/lbs at muzzle, 836 ft/lbs at 100 yards, 614 ft/lbs at 200 yards. 26 ft/lbs of recoil.

3 Pyrodex pellets: 2075fps, 2300 ft/lbs at muzzle, 1571 at 100 yards, 1057 at 200 yards. 54 ft/lbs of recoil.

100 grains by weight (not volume) of Triple Seven, 1975fps, 2083 ft/lbs at muzzle, 1415 ft/lbs at 100 yards, 954 ft/lbs at 200 yards. 46 ft/lbs of recoil.

 

[griz]

The only black powder loads I have clocked gave very similar velocities. I used a 240 gr SWCHP and IIRC it was about 1400 FPS from 80 gr of pyrodex. Thanks for the info.