I like these kinds of discussions as long as we have folks who will join in peacefully. Just for the fun of it a I ran a few figures. Take 1 1/8os shot, 35 grains of wad & 20 grains of powder. Total weight o be ejected out the barrel is then 1 oz or .078 lb. Fire this load from a 28" barrel on a 6 lb gun. Now yes I know that the ejecta would not move quite the full 28" but I used that figure anyway. While this load traveled that 28" the gun would have traveled in the opposite direction 5/16" & attained a recoil velocity of 14.4 FPS giving it a recoil energy of 20.93 ft/lbs.
Over the years I have formed the Firm conclusion that Recoil Velocity is of far greater importance than Recoil Energy. This is why the old British formula of a 96:1 ratio of gun to shot weight works. 1 oz of shot from a 6 lb gun & 2 oz of shot from a 12 lb gun if given the same muzzle velocity will recoil at essentially the same recoil velocity, though the heavier gun would have twice the recoil energy.
I have in the past shot both. The big Ten while obviously heavier in recoil was not at all uncomfortable. "IF" on the other hand one were to raise the velocity of that 1 oz in the 6 lb gun to double the energy or equal that of the big Ten, it would be Absolutely, Tetotally, Unbearable.
