Actually, I've shot that bullet over 100gr. of FF, also 100gr. equivalent of 777 in my Greyhawk, and found it no more unpleasant than a 12ga. slug. Wouldn't want to shoot 100 of them, but not so bad.
The Blackhorn 209 data sheet shows 100gr. eq. (70 by wt.) at 1701 fps in a 26" barrel, and 120gr. eq. (84 by wt.) at 1909.
If you wanna get a good whack, try plain old 405gr. Remington .45/70 loads from the bench in a Browning 78 with the steel, curved, rifle butt. Now that's fun!
