Gregor Woods came up with his own version of the TKO called Relative Damage Potential (RDP). I haven't studied it very much but Richard Harland feels they are an improvement over TKO values. Those who are interested a description is located on pgs 167-169 or "Ndlovu" by Harland as well as in Gregor Woods' book "Rifles for Africa."

Just a few examples of RDP #'s

700 NE= 110.0
577 NE= 59.1
500Jeff= 35.9
458 WM= 23.9
375 H&H= 11.9