Been shooting one for about 6 years now.
I load a military ball powder WC872 that i get from Jeff Bartlett at GIBrass.
It's close to the burn rate of H870 so I use the data for that powder.
130 Accubonds at 3350 from a 28 inch barrel.
Have killed 5 deer with it at ranges from 40-350 yards.
One of the 5 managed to take another step.