I want to make a couple of clarifications for my post #4 since I found my shotgun slug info.
The Lightfield Commander generates 50.0 ft/lbs of free recoil. It's velocity is listed at 2000 FPS and it's muzzle energy is
3643 ft/lbs(!) WOW!
Although it was irrelevant to the OP's needs, the Brenneke K.O. generates 23.7 ft/lbs of free recoil.
Just a little FYI:------------------------------muzzle vel. --- muzzle ener.
Remington's 3" Buckhammer: 37.2 ft/lbs of recoil -- 1500 FPS -- 3232 ft/lbs
Brenneke 3" Black Magic: 37.3 ft/lbs of recoil -- 1502 FPS -- 3014 ft/lbs
Brenneke 3" Gold Magnum: 37.3 ft/lbs of recoil -- 1502 FPS -- 3014 ft/lbs