The chart only incorpaorates the possible effects of a "permanent wound channel" or Trauma Cavity. It doesn't take into count the temporary one that is caused by the energy transferrence and resulting tissue, organ and psychological damage. The "knockdown" (misnomer) power of a cartridge is actually how much energy is absorbed by a body and how the body reacts to that energy. Thus a .17 HM2 has a TKO value of 0, according to the chart. BUT.... dump one into a coyote and check out the internal damage. Speed plus mass equals energy (E=MC2), as long as that bullet doesn't exit, all its energy is absorbed by the body and therefore KNOCKS DOWN the body. Easy explanations will often lead you slightly astray of the truth. Anyway, just my $.02

E=MC2 is energy equals mass times velocity squared. Momentum is mass times velocity.

Ft/lbs or Taylor TKO or whatever standard you choose to use is simply a way to compare individual cartridges to one another, neither is an absolute measure as shot placement, permanent and temporary wound cavity, CNS complexity of the game and so on all have a real world on game effect that a simple energy or TKO number can relate. TKO takes into account frontal diameter of the bullet, a factor lacking in a straight ft/lbs of energy figure. Shock isn't factored into either figure and there is a "hydrostatic" shock factor, that bloodshot meat is the result of that effect and it does contribute to temporary incapacitation of the animal, it doesn't kill immediately as some would say. In short it's a comparison tool we use to estimate effectiveness or suitability of a chambering against another.