This formula is simple. You take the weight of the bullet (in grains), times the speed (in feet per second), times the diameter (in inches - like .451) and after multliplying the results, you divide by 7000 to give you a reasonable number to work with, somewhere between 1 and 100. Perhaps he used 7000 because that's how many grains makes a pound, but in any event it gives a workable number. ( TKOF = weight * speed * diameter / 7000 )
This formula is biased towards the bigger and heavier bullets, but that's what he wanted to have a scale to Knock Out big game. Plug in some light 30-06 loads and compare to some 500 S&W loads with a very heavy bullet for comparisons. Example: A 30 caliber 150 grain bullet moving at 3,000 fps = 19.3, while a 50 caliber, 630 grain bullet moving at 1300 fps = 58.5 a huge difference, but for Taylor, he felt that's what would take down big game best. If you want to save your data, print this page after you make a calculation.